Terebellides norvegica, Parapar & Capa & Nygren & Moreira, 2020

Parapar, Julio, Capa, Maria, Nygren, Arne & Moreira, Juan, 2020, To name but a few: descriptions of five new species of Terebellides (Annelida, Trichobranchidae) from the North East Atlantic, ZooKeys 992, pp. 1-58 : 1

publication ID	https://dx.doi.org/10.3897/zookeys.992.55977
publication LSID	lsid:zoobank.org:pub:0F038B5B-120E-4583-8E85-4092C9798566
persistent identifier	https://treatment.plazi.org/id/659C513E-01DD-43A0-AC29-D1A744EDA9B0
taxon LSID	lsid:zoobank.org:act:659C513E-01DD-43A0-AC29-D1A744EDA9B0
treatment provided by	ZooKeys by Pensoft
scientific name	Terebellides norvegica
status	sp. nov.

Treatment

Terebellides norvegica sp. nov. Figs 1 View Figure 1 , 2 View Figure 2 , 3G View Figure 3 , 9 View Figure 9 , 10 View Figure 10 , 14C-D View Figure 14 , 17E View Figure 17 , 18C View Figure 18 , 19C View Figure 19 , 22 View Figure 22 , 23 View Figure 23 ; Table 1; Suppl. material 1: Table S1; Suppl. material 2: Table S2

Species 8 - Nygren et al. 2018: 18-22, figs 5, 6, 10, Suppl. material 1: Table S1.

Material examined.

Type material. Holotype: ZMBN116378. Paratypes (36 specs): Barents Sea (ZMBN11636, ZMBN116365, ZMBN116366, ZMBN116367); Norwegian coast (GNM146323, NTNU-VM61388, NTNU-VM61389, NTNU-VM61390, NTNU-VM66569, NTNU-VM66573, NTNU-VM66574, NTNU-VM68197, NTNU-VM68198, ZMBN116362, ZMBN116363, ZMBN116368, ZMBN116369, ZMBN116370, ZMBN116371, ZMBN116372, ZMBN116373, ZMBN116374, ZMBN116375, ZMBN116376, ZMBN116377, ZMBN116379, ZMBN116380, ZMBN116381, ZMBN116382, ZMBN116383, ZMBN116384); Skagerrak (GNM14637, GNM15131, GNM15232, GNM15134, ZMBN116361).

Holotype. Complete specimen, 19.0 mm long and 1.5 mm wide (Figs 3G View Figure 3 , 19C View Figure 19 ); female with oocytes in body cavity.

GenBank accession numbers of material examined (COI).

Holotype: MG025148. Paratypes: MG025119, MG025120, MG025122, MG025124, MG025126, MG025127, MG025128, MG025129, MG025131, MG025132, MG025134, MG025135, MG025136, MG025137, MG025138, MG025139, MG025140, MG025141, MG025142, MG025143, MG025144, MG025145, MG025146, MG025147, MG025149, MG025151, MG025152, MG025153, MG025154, MG025155, MG025156. Additional material: MG025117, MG025118, MG025121, MG025123, MG025125, MG025130, MG025133, MG025150.

Diagnostic features of type material.

Complete individuals ranging from 20.0-50.0 mm in length and 1.2-5.0 mm in width (Fig. 17E View Figure 17 ). Branchial dorsal lobes lamellae with well-developed anterior papillary projections (Fig. 22C View Figure 22 ). Ventral branchial lobes hidden (Figs 19C View Figure 19 , 22A, B View Figure 22 ) or not (Fig. 3G View Figure 3 ) by dorsal ones. Lateral lappets and dorsal projection low marked, only partially present on TC2 (Fig. 22A, D View Figure 22 ). Geniculate chaetae acutely bent, with poorly marked capitium (Fig. 23A, B View Figure 23 ). Ciliated papilla dorsal to thoracic notopodia not observed. Thoracic uncini in one row (Fig. 23C View Figure 23 ) with rostrum/capitium length ratio of approximately 2: 1 and capitium with a first row of two or three medium-sized teeth, followed by several progressively smaller teeth (Fig. 23D View Figure 23 ). Abdomen with 29-38 chaetigers with type 2 uncini (Fig. 23E View Figure 23 ). Epibiont ciliates observed in some specimens (Fig. 23F View Figure 23 ).

Nucleotide diagnostic features.

All sequences of T. norvegica sp. nov. share the unique apomorphic nucleotides in positions 48 (C) and 285 (G) of the alignement.

Typ e locality.

Rogaland (Norway); at depths of between 226 and 242 m (Fig. 18C View Figure 18 ).

Distribution and bathymetry.

Barents Sea, Norwegian coast, Skagerrak; 190-1,268 m deep ( Nygren et al. 2018) (Figs 9 View Figure 9 , 18C View Figure 18 ; Suppl. material 1: Table S1).

Etymology.

The name of the new species refers to the country where members of this lineage were found, along the Norwegian coast from the Barents Sea to the Skagerrak Strait.

Remarks.

Terebellides norvegica sp. nov. is characterised by the presence of marginal papillae in the anterior region of branchial dorsal lamellae, thoracic uncini of type 3 and abdominal uncini of type 2, and by lacking ciliated papilla dorsal to thoracic notopodia (Table 1 View Table 1 ). These features are shared with species of subgroup A2: T. europaea , T. ronningae sp. nov. and T. scotica sp. nov. (Table 1 View Table 1 ), apart from the thoracic uncini type that is different in T. ronningae sp. nov. Furthermore, T. norvegica sp. nov., T. europaea and T. scotica sp. nov. also show the same variability in whether ventral branchial lobes are hidden or not by dorsal lobes. Therefore, it seems that members of these three species can only be distinguished according to the DNA sequences. However, they show little overlapping in their geographic distribution and bathymetric ranges (Figs 9 View Figure 9 , 18A, C, D View Figure 18 ). Terebellides norvegica sp. nov. inhabits deep-water habitats (mostly below 200 m) along the Norwegian coast; its distribution only overlaps with that of T. europaea in southern waters (Skagerrak). As stated before, T. europaea has a broader distribution reaching to the South NW Iberian Peninsula and is generally found in shallower habitats (<100 m) similarly to T. scotica sp. nov. Ciliate epibionts attached over dorsal body surface were also observed (Fig. 23F View Figure 23 ).

On the other hand, the internal anatomy of T. norvegica sp. nov. has been examined by transparency in one alive specimen (Fig. 14D View Figure 14 ). The digestive tract is divided in an oesophagus clearly distinguishable between TC1 and TC3, that is followed by the stomach and the associated digestive gland (TC4-TC7) and then by the intestine (from TC11). Regarding the circulatory system, a double dorsal blood vessel is present in anterior body end from which arise four afferent vessels at the level of branchial stem and into the branchiae; the coelomic cavity bears oocytes from TC11. All these internal features agree with those described by Jouin-Toulmond and Hourdez (2006) and Parapar and Hutchings (2014) for other species of the genus.

Forty sequences (see Suppl. material 2: Table S2), in 33 haplotypes, have been attributed to this species ( Nygren et al. 2018). They show 0-3.1% intraspecific divergence, larger than in other Terebellides species, and a minimum of 10.5% uncorrected genetic distance, with its closest relative being T. scotica sp. nov. (Fig. 1 View Figure 1 ).