identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03D0903AC53BB81CEE131C9A0AFEF94A.text	03D0903AC53BB81CEE131C9A0AFEF94A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cadlinidae (Bergh 1891)	<div><p>Family Cadlinidae (Bergh, 1891)</p><p>Cadlina laevis (Linné, 1767) Figure 2B</p><p>Material examined: One specimen, HAT, 22 April 2023, 21 mm, FB, NUIT-1277 (Figure 2B); Two specimens, HAM, 03 July 2023, 19, 20 mm, FB, NUIT-1292, NUIT-1293; One specimen, HAM, 06 August 2023, 39 mm, FB, NUIT-1312 .</p><p>Localities: HAM, HAT</p><p>Distribution and remarks: Cadlina laevis has previously been recorded along most of the Norwegian coast including the Tromsø region (Evertsen &amp; Bakken 2005; Artskart 2024). In Tromsø, animals were mainly observed under rocks in the stony intertidal where they were associated with the sponge Halisarca Johnston, 1842 . The observations in this study verify the species presence in the region.</p></div>	https://treatment.plazi.org/id/03D0903AC53BB81CEE131C9A0AFEF94A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC53BB81CEFF819FA09ADFB0A.text	03D0903AC53BB81CEFF819FA09ADFB0A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dorididae (Rafinesque 1815)	<div><p>Family Dorididae (Rafinesque, 1815)</p><p>Doris pseudoargus (Rapp, 1827) Figure 2A</p><p>Material examined: One specimen, THA, 08 February 2022, 19 mm, FB, NUIT-1122; One specimen, HIH, 12 February 2022, 75 mm, FB, NTNU-VM-84407/NUIT-1126 (Figure 2A); One specimen, HIL, 08 April 2022, 22 mm, FB, NTNU-VM-85652/NUIT-1157; One specimen; HIL, 26 May 2022, 15 mm, FB, NTNU-VM-85693/ NUIT-1164 .</p><p>Localities: EFJ, ESU, HIH, HIL, KFJ, TLA, TPR, TTE</p><p>Distribution and remarks:</p><p>Doris pseudoargus is widely distributed along the Norwegian coast from the Swedish border in the south to the Russian border in the north (Evertsen &amp; Bakken 2005). While reported in Russian waters for the first time as late as 2000 (Redkin &amp; Martynov 2001) D. pseudoargus is now considered a common species there. In Tromsø, animals were frequently observed all year round. Observations were made both in the intertidal and at fouling communities where animals were mainly found associated with the sponge Halichondria panicea Pallas, 1766 . Spawning was observed at all seasons. Together with other recent records from northern Norway (Artskart 2024) the findings of the present study demonstrate that D. pseudoargus has a well-established presence in the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC53BB81CEFF819FA09ADFB0A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC53BB81CEFBD1F5A0CC1FDEA.text	03D0903AC53BB81CEFBD1F5A0CC1FDEA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Goniodorididae H. Adams & A. Adams 1854	<div><p>Family Goniodorididae (H. &amp; A. Adams, 1854)</p><p>Ancula gibbosa (Risso, 1818) Figure 2C</p><p>Material examined: One specimen, HIL, 08 October 2021, FB, NTNU-VM-85735/NUIT-1009 (Figure 2C); One specimen, HIL, 27 November 2021, 6 mm, FB, NTNU-VM-84547/NUIT-1073; One specimen, TPO; 16 February 2022, 15 mm, FB; NUIT-1136; One specimen, SHE, 10 June 2022, 14 mm, FB, NTNU-VM-85643/NUIT-1171; One specimen, HIL, 15 October 2022, 7 mm, FB, NUIT-1252 .</p><p>Localities: EKJ, HIL, KVA, SHE, TPO, TTE</p><p>Distribution and remarks: Ancula gibbosa has previously been reported to occur along most of the Norwegian coast including the Tromsø region (Evertsen &amp; Bakken 2005). Animals were found both in the intertidal and at fouling community localities where they were typically observed in low numbers on Saccharina latissima . All examined specimens were of the pale variant. Animals were found all year round. Prior to this study, only a single unverified record made in June 2018 by the Ocean Genome Legacy Collection exists from Tromsø (Artskart 2024). The records by the present study confirm the presence of A. gibbosa in the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC53BB81CEFBD1F5A0CC1FDEA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC53BB812EC811AFA0A71FD2A.text	03D0903AC53BB812EC811AFA0A71FD2A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Onchidorididae (J. E. Gray 1854)	<div><p>Family Onchidorididae (J. E. Gray, 1854)</p><p>Acanthodoris pilosa (Abildgaard, 1789) Figure 2D</p><p>Material examined: One specimen, ESU, 29 September 2021, FB, NTNU-VM-85732/NUIT-1063; One specimen, ESU, 14 October 2021, FB, NTNU-VM-84417/NUIT-1002; One specimen, UTE, 17 November 2021, 16 mm, FB, NTNU-VM-84546/NUIT-1019 (Figure 2D); One specimen, UTE, 04 June 2022, 18 mm, FB, NTNU- VM-85670/NUIT-1174; One specimen, UTE, 04 July 2022, 29 mm, FB, NUIT-1184; Two specimens, UTE, 28 October 2022, 19, 18 mm, FB, NUIT-1239, NUIT-1240 .</p><p>Localities: EKJ, ESU, HIL, SGU, TLA, TTE, UTE</p><p>Distribution and remarks: Acanthodoris pilosa is a commonly occurring species along the entire Norwegian coast (Evertsen &amp; Bakken 2005, Artskart 2024). It is also fairly common along the Murman coast in Russia (Martynov et al. 2006). In Tromsø, animals were observed all year round in the intertidal. Animals were mainly found associated with the bryozoan Flustrellidra hispida Fabricius, 1780 in the Ascophyllum nodosum belt. This study verifies the presence of A. pilosa in the Tromsø region.</p><p>Onchidoris bilamellata (Linnaeus, 1767) Figure 2E</p><p>Material examined: One specimen, SGU, 24 May 2020, FB, photographic record (Figure 2E); Three specimens, TVK, 12 December 2021, 27, 18, 22 mm, FB, NTNU-VM-85734/NUIT-1079, NUIT-1080, NTNU-VM-84587/NUIT-1081; One specimen, HIL, 03 December 2022, 30 mm, FB, NUIT-1253 .</p><p>Localities: EKJ, ESU, HAK, RAK, SGU, SHE, THA, TLA, TTE, TVK, UTE</p><p>Distribution and remarks: Onchidoris bilamellata occur along the entire Norwegian coast (Evertsen &amp; Bakken 2005; Artskart 2024) and has also been recorded in Russia (Martynov et al. 2006). In the present study, animals were found both in the intertidal and at fouling communities. The species was recorded all year round. Spawning was frequently observed in spring and autumn. Animals were mainly associated with the barnacles Balanus crenatus Bruguière, 1789 and Balanus balanus Linnaeus, 1758 . The present records are the first published records from the Tromsø region.</p><p>Onchidoris muricata (Müller, 1776) Figure 2F</p><p>Material examined: One specimen, THA, 06 November 2021, 16 mm, FB, photographic record (Figure 2F); One specimen, KVA, 14 November 2021, 11 mm, FB, NTNU-VM-85737/NUIT-1027; One specimen, THA, 25 November 2021, 14 mm, FB, NTNU-VM-84488/ NUIT-1069; One specimen, EKJ, 06 March 2022, 17 mm, FB, NUIT-1145 .</p><p>Localities: EKJ, ESU, HIH, HIL, KVA, RAK, SHE, THA, TPO, TPR, TTE, TVK, UTE</p><p>Distribution and remarks: Onchidoris muricata is widely distributed along the entire Norwegian coast (Evertsen &amp; Bakken 2005). The present study found the species to be commonly occurring at all months of the year where it was predominantly found on Saccharina latissima at fouling community localities.</p></div>	https://treatment.plazi.org/id/03D0903AC53BB812EC811AFA0A71FD2A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC535B812EE071ABA093EFA8A.text	03D0903AC535B812EE071ABA093EFA8A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Aegiridae (P. Fischer 1883)	<div><p>Family Aegiridae (P. Fischer, 1883)</p><p>Aegires punctilucens (Orbigny, 1837) Figure 2G</p><p>Material examined: One specimen, 19 February 2021, 6 mm, FB, NTNU-VM-84437/NUIT-1001 (Figure 2G); One specimen, 14 November 2023, 5.5 mm, FB, NUIT-1336.</p><p>Localities: HIL, KVA</p><p>Distribution and remarks: Aegires punctilucens is known to occur in southern to mid-Norway (Evertsen &amp; Bakken 2005) and has also been reported north to Saltstraumen in Nordland (Moen &amp; Svensen 2020). Observations are very few due to the small size and the exceptionally good camouflage of the species. The only previously known observations from intertidal waters stem from the conscientious investigations by Carl Dons in Trøndelag (Dons 1932, 1942a). The observations by the present study are the first records from the Tromsø region and significantly extends the northern range of A. punctilucens .</p></div>	https://treatment.plazi.org/id/03D0903AC535B812EE071ABA093EFA8A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC535B812EFCC1D1A0BA1F98A.text	03D0903AC535B812EFCC1D1A0BA1F98A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Polyceridae (Alder & Hancock 1845)	<div><p>Family Polyceridae (Alder &amp; Hancock, 1845)</p><p>Limacia clavigera (O. F. Müller, 1776) Figure 2H</p><p>Material examined: One specimen, HIS, 31 July 2023, 9 mm, FB, NUIT-1308 (Figure 2H) .</p><p>Localities: HIS</p><p>Distribution and remarks: Limacia clavigera is a commonly occurring species along most of the Norwegian coast north to southern Troms. Further north, only a single unverified record from Finnmark has been reported (Artskart 2024) and the study region seem to constitute the current northern limit in the species distribution. The specimen was found on Saccharina latissima with encrusting bryozoans. The present finding is the first documented record from the Tromsø region and the northernmost published record of the species.</p><p>Palio dubia (M. Sars, 1829) Figure 2I</p><p>Material examined: One specimen, ESU, 26 August 2020, FB, photographic record (Figure 2I); One specimen, HIL, 08 April 2022, 16 mm, FB, NTNU-VM-85686/NUIT-1159; One specimen, 28 October 2022, 24 mm, FB, NUIT-1238.</p><p>Localities: EKJ, ESU, HIL, KVA, THA, TPR, UTE</p><p>Distribution and remarks: Palio dubia has previously been found along the entire Norwegian coast (Evertsen &amp; Bakken 2005) including one online record from Tromsø (Artskart 2024). P. dubia has been reported to occur on hard-bottom at 10 – 100 m depth (Moen &amp; Svensen 2020; Lundin &amp; Malmberg 2021) with most observations deeper than 20 m (Evertsen &amp; Bakken 2005). By contrast, this study found most specimens in the Ascophyllum nodosum belt where they were often found emersed above water between tides. Animals were observed at all months of the year except during summer. This study verifies the species presence in the region.</p><p>Palio nothus (Johnston, 1838) Figure 2J</p><p>Material examined: One specimen, KVA, 23 October 2021, 8 mm, FB, NUIT-1040; One specimen, UTE, 17 November 2021, 7 mm, FB, NUIT-1018; One specimen, HIL, 15 October 2022, 9 mm, FB, NUIT-1227; One specimen, HIL, 24 September 2023, 7 mm, FB, NUIT-1326 (Figure 2J) .</p><p>Localities: HIL, KVA, UTE</p><p>Distribution and remarks: Palio nothus has sometimes been confused with the more common and widespread Palio dubia in the literature. Consequently, when historical records of P. nothus from Norway were reviewed only two records of P. nothus were found from Norwegian waters (Evertsen &amp; Bakken 2005). In addition, a third, more recent, observation from Vestland County was reported in 2013 (Evertsen &amp; Bakken 2013) suggesting that the species is very rare in Norway. A few unpublished online records from southern Norway also exist (Artskart 2024). All four specimens recorded by the present study were found during autumn (September – November.) One specimen was found in the Ascophyllum nodosum belt in the intertidal. The other three were found at fouling community localities on bare surfaces or on Desmarestia aculeata encrusted with Electra pilosa . The present records are the first records from the Tromsø region and significantly extends the known range of distribution of the species to 69 degrees N.</p></div>	https://treatment.plazi.org/id/03D0903AC535B812EFCC1D1A0BA1F98A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC535B813EC281E1908C2F9CA.text	03D0903AC535B813EC281E1908C2F9CA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Polycera norvegica (Sorensen, Rauch, Pola & Malaquias 2020)	<div><p>Polycera norvegica (Sørensen, Rauch, Pola &amp; Malaquias, 2020)</p><p>Figure 2K</p><p>Material examined: One specimen, HIL, 27 November 2021, FB, NUIT-1071; Four specimens, HIL, 04 September 2022, 22, 27, 25, 22 mm, FB, NTNU-VM-85678/NUIT-1213, NTNU-VM-85659/NUIT-1216, NTNU-VM-85663/NUIT-1217, NTNU-VM-85641/NUIT-1218 (Figure 2K); One specimen, HIL, 15 October 2022, 20 mm, FB, NTNU-VM-85673/NUIT-1234; Two specimens, EKJ, 21 September 2023, 24, 23 mm, FB, NUIT-1323, NUIT-1324; One specimen, HIL, 14 November 2023, 16 mm, FB, NUIT-1339 .</p><p>Localities: EKJ, HIL, TVK</p><p>Distribution and remarks: Polycera norvegica is a newly described species which was recently separated from Polycera quadrilineata (Sørensen et al. 2020) . Earlier records of the species are, therefore, naturally sparse. The present study found P. norvegica to be a commonly occurring nudibranch in the Tromsø region during autumn and winter. Animals were typically found associated with the bryozoans Electra pilosa and Membranipora membranacea growing on Desmarestia aculeata and Saccharina latissima respectively. Specimens belonging to chromatic variants II, III, and IV (Korshunova et al. 2021) were observed. In addition, several very dark specimens, presumably belonging to a previously unknown chromatic variant, were recorded (e.g. NTNU-VM-85659/NUIT-1216, NUIT-1323, NUIT-1324). The current observations are the first published records of Polycera norvegica from the Tromsø region.</p><p>Polycera quadrilineata (Müller, 1776) Figure 2L</p><p>Material examined: One specimen, TVK, 09 October 2020, FB, photographic record (Figure 2L); One specimen, KVA, 14 November 2021, 20 mm, FB, NUIT-1023; One specimen, SKI, 06 August 2022, 23 mm, FB, NTNU-VM-85700/NUIT-1201; One specimen, EKJ, 05 October 2022, 14 mm, FB, NTNU-VM-85667/NUIT-1223 .</p><p>Localities: EKJ, HIH, HIL, KFS, KVA, SKI, THA, TPO, TPR, TTE, TVK, UTE</p><p>Distribution and remarks: Considered a southernly species (Evertsen &amp; Bakken 2005), Polycera quadrilineata has recently been recorded north to Lofoten (Artsdatabanken 2021) and southern Troms (Moen &amp; Svensen 2020; Sørensen et al. 2020; Lundin &amp; Malmberg 2021). In Russian waters the species was observed for the first time in 2005 (Martynov et al. 2006). Previous records of Polycera quadrilineata are, however, in need re-examination as recent taxonomic revision has recently separated a morphologically similar species Polycera norvegica (see this species) from P. quadrilineata (Sørensen et al. 2020; Korshunova et al. 2021; Malaquias et al. 2021). The present study found both “true” P. quadrilineata and P. norvegica sympatrically in the same habitat. Whereas both species were found mainly on Saccharina latissima encrusted with Membranipora membranacea, P. quadrilineata seemed to prefer M. membranacea while P. norvegica was more often observed associated with Electra pilosa . Specimens of P. quadrilineata observed during this study belonged mainly to chromatic variants II and IV as described by Korshunova et al. (2021). A few individuals of variants V and VI as well as one specimen of variant VII were also observed. The present records are the first records of P. quadrilineata from the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC535B813EC281E1908C2F9CA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC534B813EC281A790CF7FAAA.text	03D0903AC534B813EC281A790CF7FAAA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dendronotus europaeus (Korshunova, Martynov, Bakken & Picton 2017)	<div><p>Dendronotus europaeus (Korshunova, Martynov, Bakken &amp; Picton, 2017)</p><p>Dendronotus cf. europaeus</p><p>Figure 3B</p><p>Material examined: One specimen, KFJ, 13 October 2020, 85 mm, FB, photographic record (Figure 3B); One specimen, TPR, 19 December 2021, 54 mm, FB, NTNU-VM-83919/NUIT-1092; One specimen, KFJ, 17 November 2022, 80 mm, FB, NTNU-VM-85640/ NUIT-1244; One specimen, THA, 19 November 2022, 52 mm, FB, NTNU-VM-85658/NUIT-1248; One specimen, HIL, 03 December 2022, 65 mm, FB, NTNU-VM-85664/NUIT-1262 .</p><p>Localities: EKJ, HIL, KFJ, THA, TPO, TPR</p><p>Distribution and remarks: Dendronotus europaeus was described as a new species in 2017. It is currently not possible to reliably identify specimens based solely on external morphology (Korshunova et al. 2017c). Large animals (typically between 50 - 90 mm in total body length) displaying all external morphological features typical for Dendronotus europaeus (Korshunova et al. 2017c) are, nevertheless, reported here as Dendronotus cf. europaeus indicating likely identity. Specimens were observed mainly during autumn, both in the intertidal and at fouling communities. The present records are the first records from the Tromsø region and represent a new northernly distribution record for the species.</p></div>	https://treatment.plazi.org/id/03D0903AC534B813EC281A790CF7FAAA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC534B813EE211EDA0CC4FE2A.text	03D0903AC534B813EE211EDA0CC4FE2A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Heroidae (Gray 1857)	<div><p>Family Heroidae (Gray, 1857)</p><p>Hero formosa (Lovén, 1844) Figure 3A</p><p>Material examined: One specimen, THA, 17 February 2021, FB, NUIT-1044 (Figure 3A); One specimen, SFJ, 04 July 2021, FB, NTNU-VM-84428/NUIT-1047 .</p><p>Localities: SFJ, THA</p><p>Distribution and remarks: Hero formosa is regarded a rare and mainly deep-water species, both in Norway and elsewhere in the Northeast Atlantic (Lundin et al. 2020; Moen &amp; Svensen 2020;</p><p>Lundin &amp; Malmberg 2021; Picton &amp; Morrow 2023). Previous records are few and mainly from southern Norway Evertsen &amp; Bakken 2005). The findings by the present study show that H. formosa may also be found in shallow waters. Spawning was observed. Krause (1895) reported four specimens of H. formosa from Skattøra in Tromsø 129 years ago and to my knowledge his record is the only previous observation of the species from Tromsø. The present study verifies the presence of H. formosa in the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC534B813EE211EDA0CC4FE2A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC534B811EC281D390D17F78A.text	03D0903AC534B811EC281D390D17F78A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Dendronotus frondosus (Ascanius 1774)	<div><p>Dendronotus frondosus (Ascanius, 1774)</p><p>Dendronotus cf. frondosus</p><p>Figure 3C</p><p>Material examined: One specimen, THA, 17 August 2021, 15 mm, FB, photographic record; Two specimens, THA, 28 July 2022, 16, 10 mm, FB, NTNU-VM-85688/NUIT-1189, NTNU-VM-85684/ NUIT-1190; One specimen, EKJ, 08 August 2022, 24 mm, FB, NTNU-VM-85642/NUIT-1199 (Figure 3C) .</p><p>Localities: EKJ, ESU, HIL, KFH, KFJ, KFS, KVA, RAK, SGU, SKI, THA, TLA, TPO, TPR, TTE, TVK, UTE</p><p>Distribution and remarks: The three species Dendronotus frondosus, Dendronotus europaeus and Dendronotus lacteus cannot reliably be identified without radula examination or molecular analysis (Korshunova et al. 2017c). Specimens displaying all external morphological features typical for D. frondosus are here reported as D. cf. frondosus indicating likely identity. D. frondosus has previously been reported to be commonly occurring along the whole Norwegian coast, including Tromsø, as well as on the Murman coast in northern Russia. However, in light of newly emerged taxonomic knowledge great care must be taken when assessing the information on the reported distribution and earlier records of D. frondosus in the literature may include records of other species. The present study found the species to be a commonly occurring nudibranch in the 2020). For the Tromsø region, Krause (1895) reported D. robustus region at all months of the year. from the area in the late 19 th century (Krause 1895) but whether this and other records previously reported from the Norwegian mainland (Evertsen &amp; Bakken 2005) refer to D. velifer or to true D. robustus Dendronotus lacteus (W. Thompson, 1840) remains unknown. This study presents the first reliably documented Dendronotus cf. lacteus records of true D. robustus from the Norwegian mainland. Specimens Figure 3D were found exclusively on Saccharina latissima with encrusting bryozoans at fouling communities. Animals were observed during Material examined: One specimen, EKJ, 13 November 2021, FB, the same time period over several consecutive years with juveniles NTNU-VM-83913/NUIT-1038; One specimen, TVK, 12 December starting to appear in July. Specimens then gradually grew in size 2021, 58 mm, FB, NTNU-VM-83915/NUIT-1083; One specimen, until they disappeared in late October – early November. The species HIL, 04 September 2022, 55 mm, FB, NTNU-VM-85681/NUIT-1219; is, therefore, considered to have a well-established presence in the One specimen, BRE, 31 July 2023, FB, photographic record (Figure Tromsø region and is anticipated to have a wider distribution along the 3D). coast of the Norwegian mainland than is currently known.</p><p>Localities: BRE, EKJ, HIL, KFJ, KVA, RAK, THA, TVK</p><p>Distribution and remarks: Previous works do not list</p><p>Dendronotus lacteus as part of the Norwegian fauna (Evertsen &amp; Family Dotidae (Gray, 1853)</p><p>Bakken 2005). Currently, however, D. lacteus is thought to occur along most of the Norwegian coast (Bakken et al. 2024a) and the Doto coronata (Gmelin, 1791)</p><p>fact that D. lacteus was not previously included in the Norwegian Figure 3F</p><p>fauna is possibly because it had previously been recorded as D.</p><p>frondosus. More recent studies have further demonstrated challenges Material examined: One specimen, EKJ, 27 January 2021, 10 in identifying sympatric Dendronotus species without additional mm, FB, photographic record; One specimen, TPR, 17 August 2021, radula examination or molecular analysis (Korshunova et al. 2017c). 12 mm, FB, photographic record; Three specimens, HIL, 26 May Only large animals displaying all external morphological features 2022, 14, 11, 12 mm, FB; NTNU-VM-85690/NUIT-1165 (Figure 3F), and coloration patterns characteristic for D. lacteus are therefore NTNU-VM-85691/NUIT-1166, NTNU-VM-85692/NUIT-1168 .</p><p>here reported as Dendronotus cf. lacteus . Uniformly milky white Localities: EKJ, ESU, HIH, HIL, KVA, ROS, SFJ, THA, TPO, individuals as well as deep-red animals with large white spots dorsally TPR, TVK</p><p>on the body dominated. The present records are the first records from Distribution and remarks: Doto coronata has previously been the Tromsø region and represent a new northernmost distribution reported to be common along the entire Norwegian coast, including record for the species. The identity should, however, be confirmed by Troms, all year round from shallow waters down to ca 200 m (Evertsen radula examination or molecular analysis. &amp; Bakken 2005). This study found animals at all months of the year, both in the intertidal and at fouling community localities. The present records confirm the presence in the Tromsø region.</p><p>Dendronotus robustus (Verrill, 1870)</p><p>Figure 3E</p><p>Doto fragilis (Forbes, 1838)</p><p>Material examined: One specimen, EKJ, 10 August 2021, 27 Doto cf. fragilis</p><p>mm, FB, NTNU-VM-83910/NUIT-1014 (Figure 3E); One specimen, Figure 3G, 3H</p><p>EKJ, 16 October 2021, 37 mm, FB, NTNU-VM-83912/NUIT-1037;</p><p>One specimen, THA, 28 July 2022, 12 mm, FB, NTNU-VM-85660/ Material examined: One specimen, THA, 09 February 2021, NUIT-1188; One specimen, EKJ, 08 August 2022, 16 mm, FB, NTNU- 4 mm, FB, NUIT-1042 (Figure 3G); Four specimens, SFJ, 04 July VM-85656/NUIT-1203; One specimen, EKJ, 17 September 2022, 16 2021, FB, NTNU-VM-84447/NUIT-1057, NTNU-VM-84506/NUITmm, FB, NUIT-1222; One specimen, EKJ, 29 July 2023, 25 mm, 1058 (Figure 3H), NUIT-1059, NUIT-1060; One specimen, THA, 08 FB, NUIT-1304; One specimen, TPO, 09 August 2023, 19 mm, FB, February 2022, 10 mm, FB, NTNU-VM-85711/NUIT-1123 .</p><p>NUIT-1314. Localities: SFJ, THA, TPR</p><p>Localities: EKJ, THA, TPO Distribution and remarks: Doto fragilis has previously been Distribution and remarks: There has been considerable reported from most of Norway (Evertsen &amp; Bakken 2005; Lundin et confusion in the literature about this species and several old records al. 2020; Moen &amp; Svensen 2020). Further to the northeast, in Russian have turned out to be misidentifications. For example, records from waters, D. fragilis was observed for the first time in 2006 (Martynov et southern Norway were revised and demonstrated to be D. frondosus al. 2006). In addition, larvae have been detected in the meroplankton already in 1926 (Odhner 1926). Furthermore, in a recent paper Lundin in the Barents Sea (Descôteaux et al. 2021). Ongoing taxonomic work et al. (2017) demonstrated that two different distinct species have indicate that D. fragilis belongs to a species complex with three separate previously been mixed up under the name “ Dendronotus robustus ”; clades; a “white morph”, a “red morph” and also Doto hystrix Picton &amp; namely Dendronotus robustus and Dendronotus velifer Sars, 1878 . Brown, 1981 which, despite absence of detectable differences is still Lundin and co-workers found D. velifer to occur in deep waters (50 treated as a separate species (Martinsson et al. 2021). Considering the – 300 m) whereas “true” D. robustus was found to inhabit shallower ongoing taxonomic challenges in the D. fragilis complex, the specimens waters. According to the authors, “true” D. robustus have never recorded by the present study are here reported as Doto cf. fragilis . Both been positively reported from shallow areas of Norway or Sweden. “white morph” (Figure 3G) and “red morph” (Figure 3H) individuals, as True D. robustus has, however, reliably been reported from areas in outlined by Martinsson et al. (2021) were found. The present records are the high Arctic such as Svalbard and Jan Mayen (Moen &amp; Svensen the first records of the species from the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC534B811EC281D390D17F78A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC531B816EF8A18FA0AF5FC89.text	03D0903AC531B816EF8A18FA0AF5FC89.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Doto maculata (Montagu 1804)	<div><p>Doto maculata (Montagu, 1804)</p><p>Doto cf. maculata</p><p>Figure 3I</p><p>Material examined: One specimen, THA, 16 March 2022, 6.5 mm, FB, NTNU-VM-85736/NUIT-1147 (Figure 3I); One specimen, THA, 04 June 2022, 6 mm, FB, NTNU-VM-85694/NUIT-1170; One specimen, THA, 14 January 2023, 6 mm, FB, NTNU-VM-85696/ NUIT-1267 .</p><p>Localities: THA</p><p>Distribution and remarks: Doto maculata has been reported from southern to mid Norway (Artskart 2024). Drifting larvae has also been recorded from the Barents Sea (Descôteaux et al. 2021). Recent work on species delimitation of Doto, however, indicate that extreme care should be taken regarding identification of D. maculata (Martinsson et al. 2021) . Specimens in the present study fully matched the morphological description of D. maculata and had neither pigment dots on apical tubercules nor red markings on the inner side of the dorsolateral appendages but are nevertheless reported here as Doto cf. maculata . The present records are the first records from the Tromsø region and the first records of adult animals from northern Norway.</p></div>	https://treatment.plazi.org/id/03D0903AC531B816EF8A18FA0AF5FC89	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC531B816EF8A1B1A09EAFAEA.text	03D0903AC531B816EF8A1B1A09EAFAEA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Doto millbayana (Lemche 1976)	<div><p>Doto millbayana (Lemche, 1976)</p><p>Doto cf. millbayana</p><p>Figure 3J</p><p>Material examined: One specimen, ESU, 26 August 2021, 24 mm, FB, photographic record (Figure 3J); One specimen, EKJ, 29 July 2023, 15 mm, FB, NUIT-1303 .</p><p>Localities: EKJ, ESU</p><p>Distribution and remarks: Doto millbayana has previously only been recorded from southern Norway (Artskart 2024). All morphological characters of the specimens examined in the present study fully match the description for Doto millbayana . However, due to insufficient knowledge on the taxonomy of the genus specimens are reported here only as Doto cf. millbayana . The present records are the first records from the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC531B816EF8A1B1A09EAFAEA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC531B816EE021DFA0DACFF4A.text	03D0903AC531B816EE021DFA0DACFF4A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Tritoniidae (Lamarck 1809)	<div><p>Family Tritoniidae (Lamarck, 1809)</p><p>Candiella plebeia (G. Johnston, 1828) Figure 3K</p><p>Material examined: Three specimens, KVA, 19 February 2021, 2.5, 15, 20 mm, FB, NTNU-VM-84397/NUIT-1049-1, NTNU- VM-84397/NUIT-1049-2, NTNU-VM-84397/NUIT-1049-3; One specimen, KVA, 30 January 2022, 7 mm, FB, NTNU-VM-84398/ NUIT-1120; KVA, 26 December 2022, 26 mm, FB, NTNU-VM-85710/ NUIT-1260; One specimen, KVA, 25 November 2023, 22 mm, FB, NUIT-1345 (Figure 3K) .</p><p>Localities: HIL, KVA, TVK</p><p>Distribution and remarks: Candiella plebeia has previously been recorded north to Trøndelag in mid-Norway (Evertsen &amp; Bakken 2005; Lundin et al. 2020; Moen &amp; Svensen 2020). Relatively few observations are known, possibly because of the species superb camouflage which makes it very difficult to observe. All specimens were found in direct association with its preferred prey Alcyonium digitatum Linnaeus, 1758 . As A. digitatum is only very infrequently found in such shallow waters as those investigated by this study it seems plausible that the species has a well-established presence in the region. The present records are the first from the Tromsø region and significantly extends the known range in distribution for the species.</p></div>	https://treatment.plazi.org/id/03D0903AC531B816EE021DFA0DACFF4A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC531B817EC2819190A1AFD8A.text	03D0903AC531B817EC2819190A1AFD8A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Aeolidia filomenae (Kienberger, Carmona, Pola, Padula, Gosliner and Cervera 2016)	<div><p>Aeolidia filomenae (Kienberger, Carmona, Pola, Padula, Gosliner and Cervera, 2016)</p><p>Figure 3L</p><p>Material examined: One specimen, HIL, 08 October 2021, FB, NTNU-VM-84388/NUIT-1140 (Figure 3L); One specimen, HIL, 09 January 2022, 45 mm, FB, NTNU-VM-84446/NUIT-1113; One specimen, HIL, 08 April 2022, 36 mm, FB, NTNU-VM-85645/ NUIT-1158; One specimen, HIL, 12 June 2022, 50 mm, FB, NTNU- VM-85741/NUIT-1177 . One specimen, HIS, 04 August 2023, 11 mm, FB, NUIT-1311 .</p><p>Localities: ESU, HIH, HIL, HIS, KFS, KVA, TPO, TVK</p><p>Distribution and remarks: Aeolidia filomenae was recently described when the cosmopolitan species Aeolidia papillosa was shown to be part of a species complex of four sibling species (Kienberger et al. 2016). While information on the distribution is naturally sparse, recent records indicate a fairly wide distribution in Norway (Moen &amp; Svensen 2020; Artskart 2024). The present study found A. filomenae to be a common species all year round both in the intertidal and at fouling community localities. Specimens were often found sandwiched between blue mussels. Spawning was mainly observed during spring and summer. The present records are the first from the Tromsø region and constitute a new northerly distribution record for the species.</p><p>Aeolidia papillosa (Linnaeus, 1761) Figure 4A</p><p>Material examined: One specimen, KVA, 06 March 2021, 85 mm, FB, photographic record Two specimens, HIL, 27 November 2021, 25, 50 mm, FB, NTNU-VM-84508/NUIT-1076, NTNU-VM-84517/ NUIT-1077; Three specimens, TVK, 12 December 2021, 20, 40, 60 mm, FB, NTNU-VM-84477/NUIT-1086, NTNU-VM-84486/NUIT-1087, NTNU-VM-84408/NUIT-1088; Three specimens, HIL, 09 January 2022, 20, 30, 50 mm, FB, NTNU-VM-84518/NUIT-1106, NTNU-VM-84526/NUIT-1107, NTNU-VM-84527/NUIT-1108; One specimen, THA, 16 March 2022, 30 mm, NTNU-VM-85674/NUIT-1146 . One specimen, KVA, 26 November 2022, 50 mm, NUIT-1257 (Figure 4A) .</p><p>Localities: ESU, HIH, HIL, HMY, KFH, KVA, RAK, SGU, THA, TPO, TTE, TVK</p><p>Distribution and remarks: Aeolidia papillosa is known from all the coast of Norway (Evertsen &amp; Bakken, 2005) and northwestern Russia (Martynov et al. 2006). A. papillosa was, however, recently shown to be part of a species complex of four sibling species (Kienberger et al. 2016). Previous records of A. papillosa may, therefore, refer to either A. papillosa or A. filomenae . The species was commonly observed all year round both in the intertidal and at fouling community localities. Spawning was observed from April – July and juveniles were typically observed in November - December. This study documents the presence of “true” A. papillosa in the Tromsø region.</p><p>Aeolidiella glauca (Alder &amp; Hancock, 1845) Figure 4B</p><p>Material examined: One specimen, HIS, 31 July 2023, 52 mm, FB, NUIT-1309 (Figure 4B) .</p><p>Localities: HIS</p><p>Distribution and remarks: Aeolidiella glauca is an uncommon species in Norway with a scattered distribution range (Evertsen &amp; Bakken 2005). The relatively few records are from southern and western Norway. The specimen in the present study was found on Saccharina latissima growing at a fouling community. The present record constitutes a new northernmost distribution record and a significant range extension for the species.</p></div>	https://treatment.plazi.org/id/03D0903AC531B817EC2819190A1AFD8A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC530B817ECA21A3A0B78FB0A.text	03D0903AC530B817ECA21A3A0B78FB0A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Coryphellidae (Bergh 1889)	<div><p>Family Coryphellidae (Bergh, 1889)</p><p>Coryphella browni (Picton, 1980) Figure 4F</p><p>Material examined: One specimen, ESU, 08 January 2022, 50 mm, FB, NTNU-VM-83908/NUIT-1103; One specimen, HIL, 09 January 2022, 15 mm, FB, NTNU-VM-84427/NUIT-1104 (Figure 4F); One specimen, HIL, 25 December 2023, 40 mm, FB, NUIT-1347 .</p><p>Localities: ESU, HIL</p><p>Distribution and remarks: The information on Coryphella browni in the literature is confusing. The species was considered not to be part of the Norwegian nudibranch fauna by Evertsen and Bakken (2005), but after rectification of misidentifications it is now considered an abundant species with a wide distribution (T. Bakken, NTNU, pers. comm., 2024). The present study found the species at most seasons of the year. The present records are the first records from the Tromsø region and constitute a new northernmost distribution record of the species.</p></div>	https://treatment.plazi.org/id/03D0903AC530B817ECA21A3A0B78FB0A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC530B817EE0F1A1A0D18FDAA.text	03D0903AC530B817EE0F1A1A0D18FDAA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Facelinidae (Bergh 1889)	<div><p>Family Facelinidae (Bergh, 1889)</p><p>Facelina auriculata (Müller, 1776) Figure 4C</p><p>Material examined: One specimen, KVA, 14 November 2021, 15 mm, FB, NUIT-1031; One specimen, HIL, 12 February 2022, 15 mm, FB, NUIT-1127; One specimen, HIL, 12 June 2022, 30 mm, FB, NTNU-VM-85680/NUIT-1175 (Figure 4C); One specimen, SKI, 06 August 2022, 28 mm, FB, NTNU-VM-85699/NUIT-1200 .</p><p>Localities: HIL, KFS, KVA, SFJ, SGU, SKI, THA, TPR</p><p>Distribution and remarks: Facelina auriculata has previously been recorded from most of the Norwegian coast (Evertsen &amp; Bakken 2005) but not from Russian waters. In this study, F. auriculata was a commonly encountered species. It was found all year round both in the intertidal and at fouling communities. Spawning was mainly observed in July and juveniles were predominantly found in November - December. The present records are, however, the first documented records from the Tromsø region.</p><p>Facelina bostoniensis (Couthouy, 1838) Figure 4D</p><p>Material examined: Four specimens, HIL, 18 October 2020, FB, photographic record (Figure 4D); One specimen, HIL, 03 December 2022, 22 mm, FB, NTNU-VM-85712/NUIT-1255 .</p><p>Localities: HIL, KFS, TVK</p><p>Distribution and remarks: Facelina bostoniensis has previously been recorded north to Nordland (Evertsen &amp; Bakken 2005) with a few recent unverified observations as far north as Troms (Artskart 2024). In the present study, animals were found associated with Ectopleura larynx Ellis &amp; Solander, 1786 at fouling communities. All records were made during autumn – winter. The present records are the first documented records of the species from the Tromsø region.</p><p>Favorinus branchialis (Rathke, 1806) Figure 4E</p><p>Material examined: One specimen, HIL, 18 October 2020, FB, photographic record (Figure 4E); Three specimens, KVA, 14 November 2021, 7, 10, 5 mm, FB, NTNU-VM-85706/NUIT-1028, NTNU-VM-85721/NUIT-1029, NUIT-1030; One specimen, HIL, 10 April 2022, 9 mm, FB, NTNU-VM-85662/NUIT-1154; One specimen, HIL, 12 June 2022, 14 mm, FB, NUIT-1172; One specimen, HIL, 14</p><p>November 2023, 7 mm, FB, NUIT-1341.</p><p>Localities: EKJ, HIL, KFS, KVA, TVK, UTE</p><p>Distribution and remarks: Favorinus branchialis has been reported from most of the Norwegian coast north to Nordland (Evertsen &amp; Bakken 2005; Moen &amp; Svensen 2020). Old records from Russian waters were later removed due to misidentifications (Martynov et al. 2006). In the present study, F. branchialis was found to be a fairly common nudibranch occurring all year round. Specimens were found mainly during autumn in association with eggs by Onchidoris muricata and Polycera spp. on Saccharina latissima . The present records are the first records from the Tromsø region and the northernmost known observations of the species.</p></div>	https://treatment.plazi.org/id/03D0903AC530B817EE0F1A1A0D18FDAA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC530B815EC281C990ADEF9AA.text	03D0903AC530B815EC281C990ADEF9AA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Coryphella chriskaugei (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrodl & Picton 2017)	<div><p>Coryphella chriskaugei (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl &amp; Picton, 2017)</p><p>Figure 4G</p><p>Material examined: One specimen, HIL, 18 October 2020, FB, photographic record (Figure 4G); One specimen, HIL, 27 November 2021, 22 mm, FB, NUIT-1072; Three specimens, HIL, 15 October 2022, 22, 31, 15 mm, FB, NUIT-1226, NUIT-1233, NTNU-VM-85704/ NUIT-1250; One specimen, HIL, 14 November 2023, 16 mm, FB, NUIT-1340 .</p><p>Localities: HIL, SFJ</p><p>Distribution and remarks: Coryphella chriskaugei was described as recently as in 2017 (Korshunova et al. 2017a). While described under the name Fjordia chriskaugei it is currently placed under the genus Coryphella (Ekimova et al. 2022; WoRMS 2024). Prior to 2017 it was included under the name Flabellina lineata Lovén, 1846 . However, following recent major revision and reclassification (Korshunova et al. 2017a) animals previously recorded as Flabellina lineata may now refer to any of several different species. According to the review by Evertsen and Bakken (2005), Flabellina lineata was found to be distributed along the entire Norwegian coast, including the Tromsø region but as indicated above it is not known which species was recorded. In this study, C. chriskaugei was observed mainly during winter in association with Ectopleura larynx but was also found once during summer on Tubularia indivisa Linnaeus, 1758 . The present records are the first records from Tromsø and the northernmost known records of the species.</p><p>Coryphella gracilis (Alder &amp; Hancock, 1844) Figure 4H</p><p>Material examined: One specimen, THA, 28 September 2020, FB, photographic record; One specimen, TPR, 22 November 2021, 7 mm, FB, NTNU-VM-85715/NUIT-1066 (Figure 4H); Two specimens, TPO, 16 February 2022, 11, 10 mm, NTNU-VM-84568/NUIT-1134, NUIT-1135; One specimen; THA, 24 March 2022, 9 mm, FB, NTNU- VM-85682/NUIT-1151; One specimen; TPO, 07 October 2023, 10 mm, FB, NUIT-1328</p><p>Localities: ESU, HIH, HIL, THA, TPO, TPR</p><p>Distribution and remarks: Records of Coryphella gracilis are relatively few and the species has been categorized as having a southernly distribution in Norway (Evertsen &amp; Bakken 2005). Using DNA barcoding, larvae of C. gracilis have, however, recently been detected in the meroplankton in the Barents Sea (Descôteaux et al. 2021, 2022). The present study found C. gracilis to be a commonly occurring nudibranch in the Tromsø region. Animals were observed all year around where they were mainly associated with Eudendrium sp. hydroids. Spawning was mainly observed during April – June but was also observed in the autumn. The present records are the first records from the Tromsø region and constitute a new northernmost distribution record of adult specimens of the species.</p><p>Coryphella lineata (Lovén, 1846) Figure 4I</p><p>Material examined: One specimen, HIL, 15 October 2022, 36 mm, FB, NUIT-1232 (Figure 4I) .</p><p>Localities: HIL</p><p>Distribution and remarks: Coryphella lineata was, together with several other species, previously known under the name Flabellina lineata . Flabellina lineata has been recorded from the entire Norwegian coast including one record from Tromsøsundet in 1885 (Sparre-Schneider 1885). All old records are, however in need of re-examination to be able to verify species identity. Following the characters given in the recent taxonomic reassessment of the family Flabellinidae (Korshunova et al. 2017a), the present record is the first published record of Coryphella lineata from the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC530B815EC281C990ADEF9AA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC532B815EF841E390BBDFE6A.text	03D0903AC532B815EF841E390BBDFE6A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Coryphella monicae (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrodl & Picton 2017)	<div><p>Coryphella monicae (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl &amp; Picton, 2017)</p><p>Coryphella cf. monicae</p><p>Figure 4J</p><p>Material examined: One specimen, TPO, 25 March 2023, 31 mm, FB, NUIT-1275 (Figure 4J) .</p><p>Localities: TPO</p><p>Distribution and remarks: The species was described in 2017 and was placed in a new genus Gulenia which then comprised three different species; Gulenia borealis, Gulenia monicae and Gulenia orjani . More recent work has placed the species in the genus Coryphella under the name Coryphella monicae (Ekimova et al. 2022) . While C. monicae and C. orjani cannot reliably be identified to species level without DNA barcoding, subtle differences in external morphology may aid in identification (Korshunova et al. 2017a). The animal found in the present study had a narrow body and short cerata suggesting Coryphella monicae . The specimen is, however, recorded here only as Coryphella cf. monicae indicating likely identity. Coryphella monicae is so far only known from a few specimens found in southern Norway from Sognefjorden to Trondheimsfjorden (Picton &amp; Morrow 2023; Artskart 2024). The present record is the first record from the Tromsø region and represents a significant range extension in distribution.</p></div>	https://treatment.plazi.org/id/03D0903AC532B815EF841E390BBDFE6A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC532B80AEC281A790AE8FEEA.text	03D0903AC532B80AEC281A790AE8FEEA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Coryphella orjani (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrodl & Picton 2017)	<div><p>Coryphella orjani (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl &amp; Picton, 2017)</p><p>Coryphella cf. orjani</p><p>Figure 4K</p><p>Material examined: One specimen, THA, 08 February 2022, 15 mm, FB, NTNU-VM-85713/NUIT-1124 (Figure 4K) .</p><p>Localities: THA</p><p>Distribution and remarks: The species was described in 2017 and was placed in a new genus Gulenia which then comprised three different species; Gulenia borealis, G. monicae and G. orjani . More recent work has placed the species in the genus Coryphella under the name Coryphella orjani (Ekimova et al. 2022) . While C. orjani and C. monicae cannot reliably be identified to species level without DNA barcoding, subtle differences in external morphology may aid in identification (Korshunova et al. 2017a). The animal found in the present study had a broad body, long cerata and a fairly long tail, suggesting Coryphella orjani . The specimen is, however, recorded here only as Coryphella cf. orjani indicating likely identity. Coryphella orjani is so far known only from a handful different localities in southern Norway north to Trondheimsfjorden (Picton &amp; Morrow 2023; Artskart 2024). The present record is the first record from the Tromsø region and represents a significant range extension in distribution.</p><p>Coryphella verrucosa (M. Sars, 1829) Figure 4L /5A</p><p>Material examined: Three specimens, ESU, 07 November 2021, 38, 30, 25 mm, FB, NTNU-VM-84467/NUIT-1007, NTNU-VM-84418/ NUIT-1012, NTNU-VM-84578/NUIT-1013; One specimen, KVA, 14 November 2021, 35 mm, FB, NTNU-VM-85709/NUIT-1050; One specimen, TPR, 19 December 2021, 40 mm, FB, NTNU-VM-85714/ NUIT-1101; One specimen, HIL, 09 January 2022, 20 mm, FB, NUIT-1110; Two specimens, HIL, 03 December 2022, 32, 30 mm, FB, NTNU-VM-85676/NUIT-1261 (Figure 5A), NTNU-VM-85655/ NUIT-1263 (Figure 4L); Two specimens, HIL, 14 November 2023, 22, 22 mm, FB, NUIT-1337, NUIT-1338 .</p><p>Localities: EKJ, ESU, HIH, HIL, HMY, KVA, SGU, SKI, THA, TLA, TPO, TPR, TTE, TVK, UTE</p><p>Distribution and remarks: Coryphella verrucosa has previously been reported from almost the entire Norwegian coast (Evertsen &amp; Bakken 2005; Moen &amp; Svensen 2020). In Tromsø, C. verrucosa was found to be a commonly occurring species. Both the long-cerata “rufibranchialis” (Figure 4L) and short-cerata “verrucose” (Figure 5A) morphological morphs were found. The “rufibranchialis” morph was, however, by far the most common. Occasionally, individuals with bright lemon-yellow cerata were observed alongside other individuals with more typical reddish cerata. The species was found at all months of the year in a wide variety of habitats. Spawning was mainly observed in April – July with juveniles typically appearing in the autumn. Adult animals were very common during winter. The present study verifies the presence of C. verrucosa in the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC532B80AEC281A790AE8FEEA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC52DB80AECA318FA0D8FFBAA.text	03D0903AC52DB80AECA318FA0D8FFBAA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cuthonellidae (Miller 1971)	<div><p>Family Cuthonellidae (Miller, 1971)</p><p>Cuthonella concinna (Alder and Hancock, 1843) Figure 5D</p><p>Material examined: One specimen, UTE, 03 November 2021, 10 mm, FB, NUIT-1011 (Figure 5D); Three specimens, UTE, 17 November 2021, 11, 10, 8 mm, FB, NTNU-VM-84576/NUIT-1020, NTNU-VM-84566/NUIT-1021, NTNU-VM-84577/NUIT-1022; One specimen, ESU, 05 May 2022, 11 mm, FB, NTNU-VM-85698/ NUIT-1163; One specimen, RAK, 29 May 2022, 24 mm, FB, NTNU- VM-85701/NUIT-1169 .</p><p>Localities: ESU, RAK, SGU, UTE</p><p>Distribution and remarks: Cuthonella concinna was previously reported only from southern Norway (Evertsen &amp; Bakken 2005). Recent observations indicate also a more northerly distribution (Lundin et al. 2020; Artskart 2024). C. concinna has also been reported from northern Russia (Martynov et al. 2006) and larvae have been detected in the meroplankton in the Barents Sea (Descôteaux et al. 2021). These findings agree well with the results from this study where C. concinna was found to be a common species in the Tromsø region. Most animals were found in close proximation to the hydroid Dynamena pumila Linnaeus, 1758 in the Ascophyllum nodosum belt. Animals were recorded all year round. Spawning occurred from May – July and juvenile animals appeared in October – November. Animals were often found emerged above water during low tide, also in winter when they could be found totally surrounded by ice crystals. The present records are the first records from the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC52DB80AECA318FA0D8FFBAA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC52DB80AECAA1C3A0C51F82A.text	03D0903AC52DB80AECAA1C3A0C51F82A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Cuthonidae (Odhner 1934)	<div><p>Family Cuthonidae (Odhner, 1934)</p><p>Cuthona nana (Alder and Hancock, 1842) Figure 5E</p><p>Material examined: Two specimens, TPO, 16 February 2022, 6, 10 mm, FB, NTNU-VM-85731/NUIT-1131, NUIT-1137; Three specimens, THA, 10 November 2022, 9, 15, 13 mm, FB, NUIT-1241, NTNU-VM-85646/NUIT-1242 (Figure 5E), NUIT-1245; One specimen, THA, 14 January 2023, 13 mm, FB, NTNU-VM-85647/ NUIT-1268 .</p><p>Localities: HIL, KVA, THA, TPO, TPR</p><p>Distribution and remarks: Cuthona nana has previously been reported from the entire Norwegian coast (Evertsen &amp; Bakken 2005). There are also three known records from the Barents Sea (Martynov et al. 2006). The species is typically found on hermit crab shells where it feeds on Hydractinia echinata Fleming, 1828 (Lundin et al. 2020). Despite being reported to be found mainly at ca 10-35 m depth and almost exclusively on places with colonies of Hydractinia echinata the present study found C. nana to be commonly occurring in shallow waters. Animals were typically found crawling on artificial surfaces with little identifiable prey. In such habitats, specimens were, nonetheless, observed both copulating and spawning. The species was observed during all seasons except summer and reproduction seemed to occur almost all year round. The present study verifies the presence of C. nana in the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC52DB80AECAA1C3A0C51F82A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC52DB80AEE0119FA0A88F82A.text	03D0903AC52DB80AEE0119FA0A88F82A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Flabellinidae (Bergh 1889)	<div><p>Family Flabellinidae (Bergh, 1889)</p><p>Carronella (Korshunova, Martynov, Bakken, Evertsen, Fletcher, Mudianta, Saito, Lundin, Schrödl &amp; Picton, 2017) Carronella sp.</p><p>Figure 5B</p><p>Material examined: One specimen, HIL, 09 January 2021, FB, photographic record; One specimen, HIL, 27 November 2021, 17 mm, FB, NTNU-VM-84536/NUIT-1070; Two specimens, HIL, 09 January 2022, 27, 20 mm, FB, NUIT-1114, NTNU-VM-84537/NUIT-1115; One specimen, THA, 08 February 2022, 35 mm, FB, NTNU-VM-84466/ NUIT-1121 (Figure 5B); One specimen, HIL, 12 February 2022, 25 mm, FB, NTNU-VM-84507/NUIT-1129; One specimen, HIL, 03 December 2022, 34 mm, FB, NUIT-1256 .</p><p>Localities: HIL, THA, TPO</p><p>Distribution and remarks: There are two known species within the genus Carronella; Carronella pellucida Alder and Hancock, 1843 and Carronella enne Korshunova et al. 2017 . It is currently not possible to identify the two Carronella species based on external morphology (Korshunova et al. 2017a). Both species have, however, been recorded from Norway based on DNA barcoding (Bakken et al. 2024a). Prior to 2017, the two species were treated as one under the name Flabellina pellucida . F. pellucida has been recorded north to Trøndelag in mid-Norway (Evertsen &amp; Bakken 2005). Recently, F. pellucida was also reported from Russian waters for the first time (Ekimova et al. 2019). The present study found Carronella to be commonly occurring in the Tromsø region, thus bridging the gap in distribution between mid-Norway and Russia. Animals were found all year round except during summer. Spawning was observed in spring. True identity of the specimens collected in the present study (here reported as Carronella sp.) as well as from other regions remains to be ascertained. The records in the present study are the first of Carronella from the Tromsø region.</p><p>Edmundsella pedata (Montagu, 1816) Figure 5C</p><p>Material examined: One specimen, SFJ, 04 July 2021, FB, NUIT-1035 (Figure 5C) .</p><p>Localities: SFJ</p><p>Distribution and remarks: Edmundsella pedata has, under the name Flabellina pedata, previously been recorded in southern Norway (Evertsen &amp; Bakken 2005; Lundin et al. 2020). Moen and Svensen (2020) also mention observations north to Nordland. The present record is the first record from the Tromsø region and represents a significant range extension in distribution.</p></div>	https://treatment.plazi.org/id/03D0903AC52DB80AEE0119FA0A88F82A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC52FB808EF8A18B90C5DF80A.text	03D0903AC52FB808EF8A18B90C5DF80A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Amphorina andra (Korshunova, Malmberg, Prkic, Petani, Fletcher, Lundin & Martynov 2020)	<div><p>Amphorina andra (Korshunova, Malmberg, Prkić, Petani, Fletcher, Lundin &amp; Martynov, 2020)</p><p>Figure 5F /5G/5H</p><p>Material examined: Two specimens, KVA, 19 February 2021, FB, NTNU-VM-84496/NUIT-1006-1 (Figure 5H), NTNU-VM-84496/ NUIT-1006-2; One specimen, ESU, 29 September 2021, FB, NTNU- VM-84468/NUIT-1032 (Figure 5G), One specimen, ESU, 08 January 2022, 12 mm, FB, NTNU-VM-84558/NUIT-1102; One specimen, UTE, 26 August 2022, FB, photographic record; Two specimens, UTE, 24 October 2022, 20, 26 mm, FB, NTNU-VM-85702/NUIT-1236 (Figure 5F); NTNU-VM-85672/NUIT-1237 . One specimen, UTE, 24 September 2023, 18 mm, FB, NUIT-1322 .</p><p>Localities: ESU, KVA, UTE</p><p>Distribution and remarks: Amphorina andra was described as recently as 2020 (Korshunova et al. 2020b). Records of the species are therefore sparse but include findings north to Trondheimsfjorden (Moen &amp; Svensen 2020) and Bodø in Nordland (Lundin et al. 2020). The species occurs in several different colour forms and subdivisions (Korshunova et al. 2020b). In Tromsø, three different colour forms were observed; a uniformly bright golden yellow form (Figure 5F), a uniformly transparent-white form with a completely pale body and cerata (Figure 5G) and a moderately transparent white form with orange-yellow pigment on the tips of the cerata (Figure 5H). In the literature, a strict water depth differentiation between A. andra and the closely related Amphorina viriola has been described. While A. viriola has been found associated with low salinity above the halocline, A. andra is associated with higher salinity below the halocline (Korshunova et al. 2020b). In the present study, A. andra was found to be commonly occurring in the Ascophyllum nodosum belt in the intertidal where animals and spawn were occasionally even found emersed above water between tides. The species may thus inhabit more shallow waters than previously known. The present observations are the first records from the Tromsø region and represent a new northerly distribution record for the species.</p><p>Amphorina pallida (Alder and Hancock, 1842) Figure 5I /5J</p><p>Material examined: One specimen, EKJ, 12 December 2020, FB, photographic record (Figure 5I); One specimen, KVA, 23 October 2021, FB, NTNU-VM-85730/NUIT-1062; Three specimens, KVA, 14 November 2021, 9, 8, 7 mm, FB, NTNU-VM-84556/NUIT-1051, NTNU-VM-85668/NUIT-1052, NTNU-VM-84588/NUIT-1053; One specimen, THA, 19 December 2021, 7 mm, FB, NTNU-VM-84567/ NUIT-1091; One specimen, KVA, 01 February 2022, FB, photographic record (Figure 5J) .</p><p>Localities: EKJ, ESU, HIL, KFH, KVA, THA, TVK, UTE</p><p>Distribution and remarks: Amphorina pallida has been reported from most of the Norwegian coast (Evertsen &amp; Bakken 2005; Lundin et al. 2020). The species exists in different colour variations (Korshunova et al. 2020b). In the present study, two different colour forms were observed. The most common form included specimens with extensive red-brown pigment (Figure 5I). A less frequent form included pale specimens with white pigment on the head and cerata but with none or few small reddish pigment dots on the body (Figure 5J). The species has been described as sparse and occurring mainly on hard bottom at 20-50 m depth (Moen &amp; Svensen 2020; Lundin et al. 2020). In the present study, A. pallida was, however, found to be common in shallow waters, both at fouling communities and in the intertidal. The species was recorded during all months of the year. The present records are the first records from the Tromsø region.</p><p>Eubranchus exiguus (Alder &amp; Hancock, 1848) Figure 5K</p><p>Material examined: One specimen, THA, 17 February 2021, FB, photographic record; One specimen, HIL, 14 November 2023, 4 mm, FB, NUIT-1334 (Figure 5K) .</p><p>Localities: HIL, THA</p><p>Distribution and remarks: Eubranchus exiguus has previously been reported from most of Norway (Evertsen &amp; Bakken 2005) and also from the Murman coast in Russia (Martynov et al. 2006). However, recent revision of the genus demonstrated the existence of a pseudocryptic new species hidden under the name E. exiguus (Grishina et al. 2022) . The new species, Eubranchus scintillans, was previously considered a colour form of E. exiguus . As both species are found sympatrically in the Barents and the North Seas (Grishina et al. 2022) earlier published records of E. exiguus may refer to either of the two species and are in need of re-examination to verify identity. Only two specimens of “true” E. exiguus were recorded by this study. The present observations are the first published records of “true” E. exiguus from the Tromsø region. The distributional status of “true” E. exiguus in Norway remains to be investigated.</p><p>Eubranchus rupium (Møller, 1842) Figure 5L</p><p>Material examined: One specimen, THA, 17 August 2021, 11 mm, FB, photographic record (Figure 5L); One specimen, UTE, 17 November 2021, 9, 5 mm, FB, NTNU-VM-84438/NUIT-1016; Two specimens, EKJ, 05 May 2022, 12, 11 mm, FB, NTNU-VM-85703/ NUIT-1161, NTNU-VM-85650/NUIT-1162; One specimen, HIL, 12 June 2022, 13 mm, FB, NUIT-1179; One specimen, TPO, 16 March 2023, 11 mm, FB, NUIT-1274; One specimen, EKJ, 29 July 2023, 10.5 mm, FB, NUIT-1305 .</p><p>Localities: EKJ, HIH, HIL, SKI, THA, TPO, UTE</p><p>Distribution and remarks: Eubranchus rupium was reported as a new species for the Norwegian fauna in 2013 (Evertsen &amp; Bakken 2013). In Russia, E. rupium has been reported from the Barents and White Sea (Martynov et al. 2006). Using DNA barcoding Descôteaux and co-workers also recently found E. rupium larvae north of the polar front (Descôteaux et al. 2021). The present study found E. rupium to be a commonly occurring nudibranch both at fouling communities and in the intertidal. Animals were found all year round, mainly in association with Obelia hydroids growing on Saccharina latissima . Spawning was mainly observed in May – August but was also recorded during October - November. These observations together with recent information on the species in Norway (Evertsen &amp; Bakken 2013, Bakken et al. 2024a) strongly indicate that the distribution of E. rupium in Norway is much wider than previously known. The records from the present study are however the first known records of E. rupium from the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC52FB808EF8A18B90C5DF80A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC52EB809EF8A1CF909BEF88A.text	03D0903AC52EB809EF8A1CF909BEF88A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Eubranchus scintillans (Grishina, Schepetov & Ekimova 2022)	<div><p>Eubranchus scintillans (Grishina, Schepetov &amp; Ekimova, 2022)</p><p>Figure 6A</p><p>Material examined: One specimen, THA, 19 December 2021, 4 mm, FB, NTNU-VM-85739/NUIT-1094; One specimen, THA, 16 March 2022, 3 mm, FB, photographic record; One specimen, THA, 21 June 2022, 10 mm, FB, NTNU-VM-85695/NUIT-1183 (Figure 6A); One specimen, TPO, 07 October 2023, 6 mm, FB, NUIT-1327 .</p><p>Localities: EKJ, ESU, HIL, KVA, NIP, SKI, THA, TPO, TPR, TTE, UTE</p><p>Distribution and remarks: Eubranchus scintillans is a newly described species which was until recently considered a colour form of E. exiguus (Grishina et al. 2022) . Recent records of the species are therefore few although Grishina and co-workers noted that both species occur together in the Barents and the North Seas (Grishina et al. 2022). In Tromsø, E. scintillans was found to be a commonly occurring species. Animals were found at all seasons of the year and were mainly found associated with Obelia hydroids growing on Saccharina latissima . The present records are the first records of E. scintillans in the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC52EB809EF8A1CF909BEF88A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC52EB809EF8A1FDA0C07F98A.text	03D0903AC52EB809EF8A1FDA0C07F98A.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Tergipes tergipes	<div><p>Tergipes tergipes (Forsskål in Niebuhr, 1775) Figure 6B</p><p>Material examined: One specimen, THA, 06 September 2020,</p><p>5 mm, FB, photographic record; One specimen, THA, 25 November 2021, 5 mm, FB, NTNU-VM-84516/NUIT-1068 (Figure 6B); One specimen, THA, 19 November 2022, 6 mm, FB, NTNU-VM-85651/ NUIT-1246 .</p><p>Localities: EKJ, HIL, KVA, NIP, RAK, ROS, THA, TPO, TPR</p><p>Distribution and remarks: Tergipes tergipes is known from most of the Norwegian coast (Evertsen &amp; Bakken 2005) and has also been reported to be common along the Murman coast (Martynov et al. 2006). In Tromsø, the species was commonly encountered all year round. Specimens were mainly associated with Obelia hydroids growing on Saccharina latissima . Spawning was observed most seasons of the year. The present records are, however, the first records from the Tromsø region.</p></div>	https://treatment.plazi.org/id/03D0903AC52EB809EF8A1FDA0C07F98A	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
03D0903AC52EB80CEC821E1A0A96F9EA.text	03D0903AC52EB80CEC821E1A0A96F9EA.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Trinchesiidae (F. Nordsieck 1972)	<div><p>Family Trinchesiidae (F. Nordsieck, 1972)</p><p>Catriona aurantia (Alder and Hancock, 1843) Figure 6C</p><p>Material examined: One specimen, 18 October 2020, HIL, FB, photographic record (Figure 6C); Two specimens, HIL, 27 November 2021, 24, 16 mm, FB, NTNU-VM-84458/NUIT-1074, NTNU-VM-85717/NUIT-1075; One specimen, HIL, 26 May 2022, 8 mm, FB, NTNU-VM-85687/NUIT-1167; One specimen, HIL, 15 October 2022, 22 mm, FB, NUIT-1231 .</p><p>Localities: HIL, SFJ</p><p>Distribution and remarks: Catriona aurantia has been reported to have a wide but scattered distribution in Norway (Evertsen &amp;</p><p>Bakken 2005; Moen &amp; Svensen 2020; Lundin et al. 2020). Very few Zelentia pustulata (Alder &amp; Hancock, 1854) records exist from northern Norway. A single specimen was collected Figure 6F from Dalne-Zelenetskaya Inlet, Russia in 2006 (Martynov et al. 2006). The present study found the species all year round. Animals were Material examined: One specimen, TPR, 30 December 2020, always found in close association with the hydroid Ectopleura larynx . FB, photographic record; One specimen, TPO, 16 February 2022, 13 Spawning was observed continuously over the year and egg masses mm, FB, NUIT-1133 (Figure 6F). were found close to the basal stolons of the Ectopleura colonies. The Localities: TPO, TPR present records are the first records from the Tromsø region. Distribution and remarks: Zelentia pustulata is a rare species in</p><p>Norway with only a few scattered observations (Evertsen &amp; Bakken</p><p>2005; Artskart 2024). The species has also been registered around Jan Trinchesia foliata (Forbes &amp; Goodsir, 1839) Mayen and Svalbard in the Arctic. The records by the present study Figure 6D were made during winter at fouling community localities and are the first records of the species from the Tromsø region. Material examined: One specimen, HIL, 29 July 2020, FB, photographic record; One specimen, KVA, 23 October 2021, 4 mm, FB, NUIT-1055; Two specimens, KVA, 25 December 2021, 5, 2 DISCUSSION mm, FB, NTNU-VM-84538/NUIT-1098, NTNU-VM-85725/NUIT-1099; One specimen, HIL, 09 January 2022, 2.8 mm, FB, NTNU- This study presents an annotated and illustrated inventory of the VM-85705/NUIT-1116; One specimen, KVA, 30 January 2022, 3.5 marine nudibranch fauna in shallow water habitats of the Tromsø mm, FB, NUIT-1118; One specimen, HIL, 03 December 2022, 5 mm, region. Data were collected during field surveys from land between FB; NUIT-1254; One specimen, HIL, 14 November 2023, 6 mm, FB; May 2020 and December 2023. In total, 49 species or taxa, belonging NUIT-1335 (Figure 6D). to 19 different families were recorded during the study period. This Localities: ESU, HIL, KVA, SFJ, TVK corresponds to more than double the number of species previously Distribution and remarks: Trinchesia foliata has previously reported from northern Norway. New northerly distribution records been recorded north to Helgeland (Evertsen &amp; Bakken 2005) and are presented for approximately a quarter of the Norwegian nudibranch Lofoten (Lundin et al. 2020) in Norway. Only very few and scattered fauna. In the most recent review of nudibranch distribution and records exist. In the Tromsø region, T. foliata was found to occur all diversity along the Norwegian coast, 18 different species have year round at fouling community localities. The present records are previously been recorded from the Tromsø region (Evertsen &amp; Bakken the first from the Tromsø region and significantly extends the known 2005). Thirteen of these 18 species were observed also by the present range in distribution for the species northwards to 69 degrees N. study, whereas six of the species were not found (Table 2). These all include deep-water species. Online records from the Tromsø region</p><p>(Artskart 2024) have recorded three further species or taxa not Zelentia ninel (Korshunova, Martynov &amp; Picton, 2017) recorded by the present study: Atalodoris pusilla Alder &amp; Hancock, Figure 6E 1845, Okenia nodosa Montagu, 1808 and Rostanga sp. Bergh, 1879.</p><p>When comparing the findings of this study with the latest available Material examined: One specimen, TPR, 19 December 2021, checklists from neighboring areas to the north (Svalbard, Palerud et 7.0 mm, FB, NUIT-1097; Two specimens, THA, 16 March 2022, al. 2004) and north-east (Russia, Martynov et al. 2006), almost all 4, 6 mm, FB, NTNU-VM-85727/NUIT-1148, NUIT-1149 (Figure species reported from these areas were also found in Tromsø. By such 6E); One specimen, TTE, 02 April 2022, 4.9 mm, FB, NTNU- direct comparisons as above, the species richness recorded by this VM-85644/NUIT-1153; One specimen, THA, 10 November 2022, 6 study, is considerably higher than what has previously been reported mm, FB, NUIT-1243; Three specimens, THA, 29 December 2022, from the Tromsø region. In fact, the number of recorded species 1.9, 7.1, 3.8 mm, FB, NTNU-VM-85653/NUIT-1264, NUIT-1265, compare more favorably with areas such as the Maldivian Archipelago NTNU-VM-85665/NUIT-1266; Two specimens, THA, 14 January in the Indian Ocean, where 52 different species of nudibranchs were 2023, 5.0, 6.5 mm, FB, NTNU-VM-85675/NUIT-1269, NUIT-1270; collected (Cunha et al. 2023). Similarly, from the Gujarat coast in One specimen, TPO, 03 March 2023, 2.9 mm, FB, NUIT-1271; India, 65 different nudibranch species were presented in a recent One specimen, TPO, 16 March 2023, 5.1 mm, FB, NUIT-1273; One checklist based on sampling from the area between 2014-2019 (Vadher specimen, EKJ, 29 July 2023, 5.9 mm, FB, NUIT-1302; One specimen, et al. 2020). While such comparisons make little or no sense, the TPO, 09 August 2023, 5.0 mm, FB, NUIT-1313. reason for the high species richness found in the shallow waters Localities: EKJ, HMY, KVA, THA, TPO, TPR, TTE investigated in the Tromsø region needs to be addressed. Several Distribution and remarks: Zelentia ninel was described as a reasons may explain the high species richness. First of all, rapid new species in 2017 and was then only known from the Barents Sea advances in DNA-based taxonomy and phylogeny over the past coast of northern Russia (Korshunova et al. 2017d). The first records decades, has dramatically increased the knowledge on species from Norway, where Z. ninel was reported to occur in Troms and diversity. Consequently, several new nudibranch taxa have recently Finnmark, were recently published (Broms et al. 2023). In Tromsø, been uncovered in northern and Arctic regions (e.g. Ekimova et al. the species was observed both at fouling community localities and in 2015, 2019, 2022; Shipman &amp; Gosliner 2015; Kienberger et al. 2016; the stony intertidal. Animals were mainly encountered during winter Korshunova et al. 2016, 2017a, 2017b, 2017c, 2017d, 2018, 2020a, but were also occasionally found during summer. Adult animals with 2020b, 2020c, 2021, 2023a, 2023b; Lundin et al. 2017; Martynov &amp; eggs inside their bodies were observed at all seasons. Together with Korshunova 2017; Sørensen et al. 2020; Descôteaux et al. 2021; recently published records from the Tromsø region these records Martinsson et al. 2021; Neuhaus et al. 2021; Korshunova &amp; Martynov constitute a new southernmost distribution record and a considerable 2022). While it is beyond the scope of this study to compile or update range extension for the species. checklists outside of the study area, the true diversity in the larger geographic region of the high north is unquestionably far higher than what is reflected by regional checklists. The fact that most regional checklists are outdated in nomenclature and composition gives rise to several concerns that must be kept in mind when comparing older taxonomic inventories with more recent ones. When a species is split into several new species, old records should ideally be re-examined to avoid spurious occurrence data, but are typically left with the name they were recorded under. For example, many of the “old” records in Table 2 are records of species which has later undergone splitting, so that it is impossible to reliably compare records without re-examination. In this study, the nature of such records has, to the best of my knowledge, been addressed. It is, however, important to acknowledge that updated information of the fauna in a region is a necessary prerequisite, before it is possible to make direct comparisons or attribute new distributional data as shifts in geographical ranges (Nakhaev 2016). Indeed, many recent studies have ascribed previously low sampling effort as one of the chief factors, explaining observations of higher recorded diversity in an area compared with previous knowledge (Bouchet et al. 2002; Evertsen &amp; Bakken 2013; Cunha et al. 2023). Other influencing factors include sampling methodology, as well as spatial and temporal variations in populations (e.g. Nybakken 1978; Evertsen &amp; Bakken 2002; Domenech et al. 2002; Betti et al. 2017; Cyrne et al. 2018; Lombardo &amp; Marletta 2021). As for methodology, all sampling in the present study was conducted from land in very shallow waters, with most observations being made at depths no greater than 0.5 meters. Surveys were also to a large degree conducted at fouling community localities. Such localities are difficult to compare with natural habitats, as they may be affected by anthropogenic activities which can increase connectivity between distant localities (Bishop et al. 2017). Of the few studies that have investigated nudibranch diversity in shallow waters, Clarke (1975) found that the maximum occurrence of most species occurred in a zone extending from the low subtidal to a depth of about 3 m below mean low water. Whereas highest diversity was found in this shallow belt, most species did not utilize the actual intertidal zone despite the presence of food items there (Clarke 1975). The low diversity of intertidal species was instead explained by the high thermal sensitivity of nudibranchs, and the wide temperature range of the intertidal. Other studies have reported high diversity in the intertidal (Morley &amp; Hayward 2015). Some nudibranchs have even been found to tolerate emersion above water during low tides (Cyrne et al. 2018). This phenomenon was frequently observed also in the present study. Even in wintertime in Tromsø, when ice formed rapidly between tides, several species ( Acanthodoris pilosa, Cuthonella concinna, Dendronotus frondosus and Palio dubia) were found to tolerate emersion between tides (F. Broms, personal observation). Previous studies from northern Norway have emphasized SCUBA-diving as a crucial methodology for documentation of this otherwise difficult to sample species group (Evertsen &amp; Bakken, 2002). The area investigated by the present study, have next to no overlap with previous sampling conducted by SCUBA divers, or traditional sampling techniques from research vessels. The diversity recorded here is, therefore, likely to only represent a fraction of the true diversity of the region. Yet, while SCUBA diving probably remains the most versatile sampling method for nudibranchs, it may, nonetheless, under-sample shallow habitats. While sampling in shallow waters miss out on deeper living species, the accessibility of the habitat makes it possible to carry out more exhaustive surveys. The risk of overlooking small species is also reduced compared with SCUBA diving. Of even higher importance is probably spatial and temporal variations in populations. If we want to understand species richness in an area, long-term observations of populations are crucial, but such data is very scarce in the literature. Most nudibranch species are short-lived, and sudden and dramatic changes in nudibranch populations have been widely reported by many authors (Nybakken 1978; Todd 1981; Claverie &amp; Kamenos 2008). Peaks in occurrence are therefore easily missed, unless long-term monitoring of populations are conducted (Larkin et al. 2017). In addition, annual and interannual variation in water temperature may have profound effects on dispersal, settling and survival of larvae and thus diversity (Clarke 1975). The present study is by no means a complete inventory of the nudibranch fauna of the Tromsø region. Long term survey efforts of assemblages are needed to study whether newly recorded occurrences reflect actual range expansions, or only temporary appearances due to favorable environmental conditions. Whereas it is beyond the scope of the present study to investigate seasonal occurrence in the area, locality surveys were nevertheless performed at all seasons of the year, during both night and day during a total study period spanning 44 months. It is therefore likely that this study was able to document most of the species occurring in shallow water habitats in the region. While all the above-mentioned factors may influence the diversity recorded in regional inventories, the high diversity recorded in the Tromsø region is, nonetheless, striking. While no comparative measurements of diversity were performed, species richness was found to be high both at fouling community localities and in the intertidal. Maximum number of recorded species during a single locality survey was 24 species. The fact that a higher number of species was recorded on a single locality visit, than the number of species previously recorded historically from the two northernmost counties in Norway pooled together, is noticeable. Such species richness compares, or even exceeds, that recorded at the biodiversity hot spot “Scoglio del Corallo” in the Tyrrhenian Sea, Italy. There, 23 different species of nudibranchs were found using SCUBA-diving during a project period spanning between 2013 – 2015 (Furfaro &amp; Mariottini 2016). Other recent studies reporting high diversity, include a survey from the coastal western Mediterranean where 16 nudibranch species were recorded throughout a year (Salvador et al. 2022). A survey across the Indonesian coral reef ecosystem recorded 18 nudibranch species from 16 localities (Dharmawan et al. 2021). While many new records presented by the present study are, likely, a result of increased sampling effort, there is also strong reason to believe that several species have expanded their distribution northwards in recent years. Many of the species found in Tromsø for the first time were fairly large and conspicuous and were found in easily accessible habitats. Such factors, together with the fact that many of the records were made of spawning populations over several consecutive years, indicate possible real shifts in distribution patterns. Several of the species that were found to be commonly occurring in Tromsø, while never previously recorded from the region, include species that have recently been found for the first time in Arctic Russia. Such species, where poleward range extensions have been attributed to climate warming (Martynov et al. 2006; Ekimova et al. 2019; Korshunova et al. 2021), include Catriona aurantia, Carronella sp., Doris pseudoargus, Doto fragilis, Eubranchus scintillans, Polycera quadrilineata and Tergipes tergipes . These species do, in all probability, have a wide distribution along all the coast from Tromsø to the Russian border. Several other species are likely to belong to the same category, e.g.: Aeolidia filomenae, Amphorina andra, Candiella plebeia, Coryphella browni, Coryphella chriskaugei, Coryphella gracilis, Coryphella lineata, Dendronotus europaeus, Dendronotus lacteus, Dendronotus robustus, Facelina auriculata, Favorinus branchialis and Polycera norvegica . None of these species have previously been recorded in the Tromsø region, yet they were found to be commonly occurring during this study. These species are therefore anticipated to have a wider distribution along the Norwegian coast than currently known. However, as pointed out in the Results, re-examination of old records is needed to establish if these species have already been recorded in northern Norway, but under other names.Yet other, more inconspicuous species, such as Cuthonella concinna, Doto cf. maculata, Eubranchus rupium, Trinchesia foliata and Zelentia ninel probably also have well established populations in northern Norway. Because of their tiny size and low sampling effort in shallow waters, they may simply have been overlooked previously. Most of these species have also been recorded from Russian waters, and the present findings from Tromsø do not imply any recent change in distribution. Species only rarely encountered in this study such as Aegires punctilucens, Aeolidiella glauca, Coryphella cf. monicae, Coryphella cf. orjani, Doto cf. millbayana, Edmundsella pedata, Eubranchus exiguus, Facelina bostoniensis, Hero formosa, Limacia clavigera, Palio nothus and Zelentia pustulata probably reflect true rarity, spatio-temporal rarity, or species that are only infrequently encountered in such shallow waters as those investigated by the present study. In conclusion, this study reports on a high species richness from a region which is positioned in a biogeographic transition area from boreal to Arctic waters (Spalding et al. 2007; Jirkov 2013). While several studies have found recent shifts in nudibranch distribution ranges to be explained by climate change, or other changes in environmental factors (Schultz et al. 2011; Nimbs &amp; Smith 2018; Goddard et al. 2018), range shifts have also been explained by the lack of pre-existing baseline data or improvement of previous knowledge due to increased search effort and differences in sampling methodology (Bertsch 2014; Nekhaev 2016; Chow et al. 2022; Salvador et al. 2022; Cunha et al. 2023). In light of this, the results from this study highlights the importance of an updated understanding of the distribution of marine species for effective monitoring of marine systems. As such knowledge requires reliable identifications, this study underscores the indispensability of adding molecular methods, such as DNA barcoding, to delimit species in future studies. Furthermore, the need for long term monitoring of spatial and temporal variability in nudibranch occurrences, is crucial in order to understand the persistence of species in their new ranges and determine whether the observed occurrences are persistent or temporary. Long term monitoring in relation to life history traits and environmental factors should be investigated across a wider biogeographical region in the sub-Arctic and Arctic sectors of the Northeast Atlantic. By presenting baseline biodiversity data of nudibranchs from the Tromsø region for the first time, this study hopes to serve as a baseline for more detailed studies focused on monitoring biodiversity in the Arctic region in the future.</p></div>	https://treatment.plazi.org/id/03D0903AC52EB80CEC821E1A0A96F9EA	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Broms, Fredrik	Broms, Fredrik (2024): Diversity of nudibranchs in shallow water habitats in the region of Tromsø, northern Norway. Fauna norvegica 43: 84-109, DOI: 10.5324/fn.v43i0.5840, URL: https://doi.org/10.5324/fn.v43i0.5840
