identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03F2AF08FFB5FFC2C7D227B0FB98F85B.text	03F2AF08FFB5FFC2C7D227B0FB98F85B.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Simocephalus (Echinocaudus) exspinosus (De Geer 1778)	<div><p>Simocephalus (Echinocaudus) exspinosus (De Geer, 1778) s. lato</p><p>Figs. 1A–E</p><p>De Geer 1778: 457 ( Monoculus); Flössner 1972: 184–187, Fig. 87; Orlova-Bienkowskaja 2001: 76–78, Figs. 94–99, Pl. 33–34; Hudec 2010: 160–161, Fig. 32J–M; Rogers et al. 2019: 679, Figs. 16.2.18; Korovchinsky et al. 2021b: 163, Figs. 48, 9–10.</p><p>Material examined. Numerous parthenogenetic females from a pond in Permai Lake, Ipoh, Perak (4.47728° N, 101.0492° E), 28.01.2018.</p><p>This is the first record for Peninsular Malaysia. Studied specimens have typical general morphology (Fig. 1A) and morphology of postabdomen (Fig. 1B), with the outer side of the postabdominal claw bearing a pecten of spines near the base (Figs. 1C–D). Studied specimens have clusters of darkly pigmented hypodermal cells on the valves (Figs. 1A, E), but such pigmentation was not recorded in populations from temperate regions. The species was recorded in the Sarawak State, East Malaysia by Spandl (1925). In South-East Asia, it was recorded in Thailand (Sanoamuang 1998; Maiphae et al. 2008), Vietnam (Sinev &amp; Korovchinsky 2013, as  S. congener (Koch, 1841)) and Indonesia (Korovchinsky 2013). According to Orlova-Bienkowskaja (2001),  S. expinosus has a cosmopolitan distribution, as well as its sibling-species,  S. congener . These two taxa differ only in the morphology of the postabdominal claw:  S. congener has a pecten of 20–25 thin spines on the outer side instead of 8–12 large spines in  S. expinosus . In our materials, we found specimens with intermediate number of spines (15–18), which was also observed in populations from Vietnam (Sinev &amp; Korovchinsky 2013) and Central China (Dadykin et al. 2023). Thus, we consider  S. congener as possible synonym of  S. expinosus, despite this should be tested using molecular methods. For detailed description, see Orlova-Bienkowskaja (2001).</p></div>	https://treatment.plazi.org/id/03F2AF08FFB5FFC2C7D227B0FB98F85B	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFB3FFC4C7D223F0FD80FCD9.text	03F2AF08FFB3FFC4C7D223F0FD80FCD9.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Simocephalus (Simocephalus) mixtus Sars 1903	<div><p>Simocephalus (Simocephalus) mixtus Sars, 1903</p><p>Fig. 1F–J</p><p>Sars 1903b: 174; Orlova-Bienkowskaja 2001: 56–58, Figs. 85–86, Pl. I, II, VI; Rogers et al. 2019: 678, Figs. 16.2.18 I; Korovchinsky et al. 2021b: 156–157, Figs. 46, 9.</p><p>Material examined.   Four juvenile parthenogenetic females from a pond at the Lake Permai, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.0492&amp;materialsCitation.latitude=4.47728" title="Search Plazi for locations around (long 101.0492/lat 4.47728)">Ipoh</a>, Perak (4.47728° N, 101.0492° E), 28.01.2018  .</p><p>The species has been recorded in Peninsular Malaysia only once (Mizuno &amp; Mori 1970), and Idris (1983) did not include it in his monograph. Only juvenile females were present in the studied materials. Juvenile females (Fig. 1F) have no distinctive protruding backward dorsal margin, characteristic for large adult females. Studied specimens have typical of subgenus S. ( Simocephalus) morphology of head (Fig. 1G) and postabdomen (Fig. 1I), with outer side of postabdominal claw bearing uniform thin setulae (Fig. 1J). Studied specimens have the morphology of posterior-dorsal valve prominence characteristic of the species (Fig. 1H). The species was recently found in Sabah State, East Malaysia (Sinev &amp; Yusoff 2018). In South-East Asia,  S. mixtus was recorded in the North-East Thailand (Maiphae et al. 2008) and in Hainan Island (Sinev et al. 2015). For detailed description, see Orlova-Bienkowskaja (2001). Two other species of S. ( Simocephalus), S. (S.) vetulus (O. F. Muller, 1776) and  S. (S.) vetuloides Sars, 1898 were also recorded in South-East Asia (Korovchinsky 2013), but no morphological descriptions were provided for them. According to Orlova-Bienkowskaja (2001), these species are distributed in temperate regions only, so their presence in the region is doubtful.</p></div>	https://treatment.plazi.org/id/03F2AF08FFB3FFC4C7D223F0FD80FCD9	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFB3FFC4C7D2208BFACFF8D6.text	03F2AF08FFB3FFC4C7D2208BFACFF8D6.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Streblocerus spinulatus Smirnov 1992	<div><p>Streblocerus spinulatus Smirnov, 1992</p><p>Fig. 2</p><p>Idris &amp; Fernando 1981a: 237–238, Figs. 8–10 ( pygmaeus); Idris 1983: 42–43, Fig. 20 ( pygmaeus); Smirnov 1992: 126, Figs. 528–530.</p><p>Material examined.   Several parthenogenetic females from a forest waterbody near <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.9969&amp;materialsCitation.latitude=3.12474" title="Search Plazi for locations around (long 102.9969/lat 3.12474)">Muadzam Shah</a>, Pahang, (3.12474° N, 102.9969° E), 18.10.2013 ;   11 parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=2.9186&amp;materialsCitation.latitude=3.43257" title="Search Plazi for locations around (long 2.9186/lat 3.43257)">Chini Lake</a>, Pahang state (3.43257° N, 02.9186° E), 19.03.2013 ;   several parthenogenetic females from various locations in  Bera Lake, Pahang, on 1.02.2018  .</p><p>Body shape of the studied specimens (Fig. 2A–C) is typical of the genus, with a head length of about half the length of the valves. Valves and head are covered by a peculiar scale-like sculpture. The morphology of antennule, antenna and labrum is typical of the genus (Fig. 2D–E).  Streblocerus spinulatus clearly differs from the Eurasian  S. serricaudatus s. lato (see Hudec 2010 and Tiang-nga et al. 2020), Venezuelan  S. superserricaudatus Smirnov, Alvarez &amp; Castillo, 1995 (see Smirnov et al. 1995) and West African  S. inexpectatus Dumont, 1981 (see Dumont 1981) in absence of denticles on preanal margin of the postabdomen (see Fig. 2F).  Streblocerus spinulatus differs from its sibling species,  S. pigmaeus Sars, 1901, in having much longer setulae on preanal margin of the postabdomen (see Fig. 2F).</p><p>Streblocerus spinulatus was described by Idris &amp; Fernando (1981a) from Peninsular Malaysia as  S. pygmaeus Sars, 1901, although the latter is described from Brazil and is known from the Central and South America. Smirnov (1992) has proposed that this population belongs to a distinct species.  Streblocerus spinulatus is known from a few localities in Peninsular Malaysia: Chini Lake, Pahang (our data), Subang Lake, Selangor, Batang Bertunjai pond, Selangor and Mengkarak rice field and Pahang (Idris &amp; Fernando 1981a). Also, the species was observed in one locality in Sabah, East Malaysia (Sinev &amp; Yusoff 2018) and in North-East Thailand (Tiang-nga et al. 2020). Records of  Streblocerus from China in Chiang &amp; Du (1979) might also belong to  S. spinulatus and should be revised.</p></div>	https://treatment.plazi.org/id/03F2AF08FFB3FFC4C7D2208BFACFF8D6	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFB2FFC5C7D22668FE35F8D3.text	03F2AF08FFB2FFC5C7D22668FE35F8D3.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bosmina (Sinobosmina) fatalis Burckhardt 1924	<div><p>Bosmina (Sinobosmina) fatalis Burckhardt, 1924</p><p>Figs. 3A–D, 4A–B</p><p>Burckhardt 1924: 235–237, 240–241, Fig. 10 (fatalis,  fatalis var. cyanopotamia,  fatalis var. megalolimnetis); Chiang &amp; Du 1979: 170–172, Fig. 112; Lieder 1983: 127, Figs. 2, 7b, 8b; Kotov et al. 2009: 14–17, Figs. 6–8 (fatalis, fatalis cyanopotamia); Kotov et al. 2012: 69–71, Fig. 15; Korovchinsky et al. 2021b: 247–249, Figs. 72, 7–11.</p><p>Material examined.   Over 20 parthenogenetic females from Putrajaya <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.6926&amp;materialsCitation.latitude=2.94434" title="Search Plazi for locations around (long 101.6926/lat 2.94434)">Wetland</a>, Putrajaya (2.94434° N, 101.6926° E), coll. in 24.01.2018  .</p><p>This is the first record for Malaysia. The species was previously reported from the same locality by Umi et al. (2020) as  B. (Bosmina) longirostris . Studied specimens have the morphology typical of the species (Figs. 3A–D, 4A), including characteristic position of lateral head pore (Fig. 3C), and horseshoe-shaped frontal head pore (Fig. 4B). The species clearly differs from other species found in Malaysia,  B. (Liederobosmina) meridionalis, in position of the lateral head pore and shape of the frontal pore.  B. (S.) fatalis is endemic to East and Southeast Asia, distributed in Thailand, Cambodia, the Philippines, eastern China, Korea and Japan (Maiphae et al. 2008; Tanaka &amp; Ohtaka 2010; Korovchinsky et al. 2021b). For detailed description of female see Kotov et al. (2012), for description of male see Kotov et al. (2009).</p></div>	https://treatment.plazi.org/id/03F2AF08FFB2FFC5C7D22668FE35F8D3	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFB1FFC6C7D227B3FAD6F8C2.text	03F2AF08FFB1FFC6C7D227B3FAD6F8C2.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Bosmina (Liederobosmina) meridionalis Sars 1904	<div><p>Bosmina (Liederobosmina) meridionalis Sars, 1904</p><p>Figs. 3E–H, 4C–F</p><p>Sars 1904: 63–63, Pl. 34, Figs. 3a–c. Kořínek 1971: 286–289, Figs. 8A–F; Kořínek 1983: 89–90, Figs. 104–107; Kořínek, Sacherová &amp; Havel 1997: 15; figs. 2C, 4F; Kotov et al. 2009: 19–21, Figs. 9–10.</p><p>Material examined.   Several parthenogenetic females from a tin-mining lake in <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.6685&amp;materialsCitation.latitude=2.86975" title="Search Plazi for locations around (long 101.6685/lat 2.86975)">Dengkil</a>, Selangor (2.86975° N, 101.6685° E), 5.10.2013 ;   numerous parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.691&amp;materialsCitation.latitude=3.27472" title="Search Plazi for locations around (long 101.691/lat 3.27472)">Batu Dam</a> reservoir, Selangor (3.27472° N, 101.691° E), 30.11.2014 ;   numerous parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=100.6582&amp;materialsCitation.latitude=5.04147" title="Search Plazi for locations around (long 100.6582/lat 5.04147)">Bukit Merah</a> reservoir, Perak state (5.04147° N, 100.6582° E), 26.01.2018 ;   several parthenogenetic females from a pond at <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=100.7518&amp;materialsCitation.latitude=4.85679" title="Search Plazi for locations around (long 100.7518/lat 4.85679)">Taiping</a>, Perak state (4.85679° N, 100.7518° E), 04.12.2014 ;   numerous parthenogenetic females from Garden Lake, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=100.7122&amp;materialsCitation.latitude=4.91688" title="Search Plazi for locations around (long 100.7122/lat 4.91688)">Taiping</a>, Perak (4.91688° N, 100.7122°E), 26.01.2018  .</p><p>This is the first record for Malaysia. Studied specimens have the morphology typical of the species (Figs. 3E–F, 4C–F), including characteristic position of lateral head pore (Figs. 3G, 4D– E) and rounded frontal head pore (Fig. 4F).  Bosmina (Liederobosmina) meridionalis is the only species of subgenus  Liederobosmina present in the East Hemisphere, the taxon was first described from Australia and New Zealand (Sars 1904) and is common in the Indo-Malaysian Province (Sanoamuang 1998; Maiphae et al. 2008; Tanaka &amp; Ohtaka 2010; Chattergee et al. 2013). For the description of female see Kořínek (1983, 1999) and for the description of male see Kotov et al. (2009).</p></div>	https://treatment.plazi.org/id/03F2AF08FFB1FFC6C7D227B3FAD6F8C2	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFB0FFC9C7D22423FE70FD93.text	03F2AF08FFB0FFC9C7D22423FE70FD93.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Acroperus africanus Neretina & Kotov 2015	<div><p>Acroperus africanus Neretina &amp; Kotov, 2015</p><p>Fig. 5</p><p>Idris 1983: 128–130, Fig. 61 ( harpae); Neretina &amp; Kotov 2015: 517–524, Figs. 1–5; Sinev 2016: 457, Figs. 5A–D; Kotov et al. 2017: 238–240, Fig. 8.</p><p>Material examined.   Several parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.92225&amp;materialsCitation.latitude=3.43224" title="Search Plazi for locations around (long 102.92225/lat 3.43224)">Chini Lake</a>, Pahang (3,43224° N, 102,92225° E), 19.10.2013 ;   numerous parthenogenetic females, and one male from several locations at  Bera Lake, Pahang, 01.02.2018  .</p><p>Acroperus africanus was described based on the material from Ethiopia and the Republic of South Africa (Neretina &amp; Kotov 2015). Later,the species was found in South Korea (Kotov et al. 2017) and North-East Thailand (Sinev 2016; Tiang-nga et al. 2020). Earlier records of  Acroperus from South-East Asia, including Malaysia (Idris 1983), were attributed to  A. harpae (Korovchinsky 2013), but their morphology was never studied in details.  Acroperus harpae and  A. africanus clearly differ in morphology of the antenna and male postabdomen.</p><p>Morphology of the studied parthenogenetic females fully agree with that from the description of  A. africanus (see Neretina &amp; Kotov 2015), including body of moderate height for the genus and moderately developed head keel (Fig. 5A), small closely spaced denticles on posteroventral angle of valves (Fig. 5B), postabdomen morphology typical of the genus (Fig. 5C), antennal branches of similar length, presence of a short seta on basal segment of antennal exopodite, and uniform apical setae (Fig. 5D). Prior to our study, males of  A. africanus have been known only for Korean populations (Kotov et al. 2017), while males from Africa have never been described. Studied male from Malaysia slightly differs from the South Korean specimens in shape of its postabdomen, the latter have somewhat broader posterior portion (see Kotov et al. 2017, Fig.8L), but this difference can be explained by an interspecies variability. Idris (1983) described outer morphology and the shape of postabdomens of both male and female of  Acroperus from Malaysia, male morphology is the same as in studied material. For detailed description of female see Neretina &amp; Kotov (2015).</p></div>	https://treatment.plazi.org/id/03F2AF08FFB0FFC9C7D22423FE70FD93	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFBEFFC9C7D2210DFE59FAA1.text	03F2AF08FFBEFFC9C7D2210DFE59FAA1.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Anthalona spinifera Tiang-nga, Sinev & Sanoamuang 2016	<div><p>Anthalona spinifera Tiang-nga, Sinev &amp; Sanoamuang, 2016</p><p>Figs. 6A–E</p><p>Tiang-nga, Sinev &amp; Sanoamuang 2016: 94–99, Figs. 1–3; Sinev &amp; Yusoff 2018: 368, Figs. 1I–L.</p><p>Material examined.   Several parthenogenetic females from a forest waterbody near <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.9969&amp;materialsCitation.latitude=3.12474" title="Search Plazi for locations around (long 102.9969/lat 3.12474)">Muadzam Shah</a>, Pahang (3.12474° N, 102.9969° E), 18.10.2013 ;   several parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.9186&amp;materialsCitation.latitude=3.43257" title="Search Plazi for locations around (long 102.9186/lat 3.43257)">Chini Lake</a>, Pahang (3.43257° N, 102.9186° E), 19.10.2013 ;  one parthenogenetic female from pond near Pahang river, Pahang (3.44933° N, 103.0478° E), 19.10.2013;   several parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.5265&amp;materialsCitation.latitude=3.24675" title="Search Plazi for locations around (long 101.5265/lat 3.24675)">Biru Lake</a>, Selangor (3.24675° N, 101.5265° E), 30.11.2014 ;   three parthenogenetic females from  Chini Lake, Pahang (3.42026 ° N, 102.92990° N), 5.09.2022  .</p><p>This is the first record for the Peninsular Malaysia. Studied specimens have somewhat higher, more ovoid body (Fig. 6A) as compared to the specimens reported from Thailand and Malaysian Borneo, but share a characteristic morphology of labrum (Fig. 6C), postabdomen (Fig. 6D), and inner distal lobe of limb I bearing remarkable setae 1–2, ending in large spines (Fig. 6E). The latter character, shared only by  A. vandammei, clearly separates  A. spinifera from most of other East Asian  Anthalona species. The species is very close in morphology to  Anthalona vandammei (see below) but differs from it in the short posterior setae on valves and more numerous setulae (about 25) at postero-ventral angle of valves (Fig. 6B).</p><p>Rare endemic of South-East Asia, previously known from North-East Thailand (Tiang-nga et al. 2016) and Sabah, East Malaysia (Sinev &amp; Yusoff 2018). The species is associated with macrophytes. For detailed description see Tiang-nga et al. (2016).</p></div>	https://treatment.plazi.org/id/03F2AF08FFBEFFC9C7D2210DFE59FAA1	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFBEFFC9C7D2261AFD6DF823.text	03F2AF08FFBEFFC9C7D2261AFD6DF823.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Anthalona vandammei Sinev, Tiang-nga, & Sanoamuang 2023	<div><p>Anthalona vandammei Sinev, Tiang-nga, &amp; Sanoamuang, 2023</p><p>Figs. 6F–J</p><p>Maiphae, Pholpunthin &amp; Dumont 2008: 34, Fig. 2b ( Alona verrucosa); Sinev, Tiang-nga &amp; Sanoamuang 2023: 68–74, Figs. 1–5.</p><p>Material examined.   Three parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.60639&amp;materialsCitation.latitude=3.13704" title="Search Plazi for locations around (long 102.60639/lat 3.13704)">Bera Lake</a>, Pahang (3.13704° N, 102.60639° E), 01.02.2018  .</p><p>This is the first record for Malaysia. Studied specimens have a body shape typical of the species (Fig. 6F), morphology of valves (Fig. 6G), head pores (Fig. 6H), labrum (Fig. 6I) and postabdomen (Fig. 6J). The species is very close in morphology to  Anthalona spinifera but differs from this and all other East Asian species of the genus in long posterior setae on valves (Fig. 6G), with the last setae located at postero-ventral angle of valves, followed by 15 short setulae only. For detailed description see Sinev et al. (2023).</p><p>Anthalona vandammei is a rare endemic of South-East Asia, previously known from Lake Kud-Thing in Bueng Kan Province, North-East Thailand, and in Thungtong swamp in Surat Thani Province, Southern Thailand (Sinev et al. 2023). The species is associated with macrophytes.</p></div>	https://treatment.plazi.org/id/03F2AF08FFBEFFC9C7D2261AFD6DF823	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFBDFFCFC7D2256FFEB7FB63.text	03F2AF08FFBDFFCFC7D2256FFEB7FB63.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Coronatella (Coronatella) acuticostata (Sars 1903)	<div><p>Coronatella (Coronatella) acuticostata (Sars, 1903)</p><p>Figs. 7–9, 10A–G</p><p>Sars 1903a: 15, pl. I, Figs. 5, 5a–c ( Alona); Stingelin 1905: 349–350, Taf. 12, Figs. 18–19 ( Alona acuticostata var. tridentata); Idris &amp; Fernando 1981a: 250, Figs. 67–71 ( Alona monacantha); Idris 1983: 117, Fig. 35. ( Alona monacantha); Sinev &amp; Yusoff 2015: 585–586, Figs.1F–G; Sinev 2016: 467, Figs. 9A–D.</p><p>Material examined:   several parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=100.6787&amp;materialsCitation.latitude=4.9852" title="Search Plazi for locations around (long 100.6787/lat 4.9852)">Bukit Merah</a> reservoir, Perak (4.9852° N, 100.6787° E), 26.01.2018 ;   11 parthenogenetic females from Putrajaya <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.7025&amp;materialsCitation.latitude=2.97552" title="Search Plazi for locations around (long 101.7025/lat 2.97552)">Wetland</a> (02.97552° N, 101.70250° E), 3.09.2022 ;   parthenogenetic female from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.90849&amp;materialsCitation.latitude=3.42484" title="Search Plazi for locations around (long 102.90849/lat 3.42484)">Chini Lake</a>, Pahang (03.42484° N, 102.90849° E), 5.09.2022 ;  over 30 parthenogenetic females from a roadside pond, Pahang (03.45092° N, 102.86503° E), 6.09.2022;   several parthenogenetic females from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.00976&amp;materialsCitation.latitude=3.41537" title="Search Plazi for locations around (long 103.00976/lat 3.41537)">Mentiga Lake</a>, Pahang (03.41537° N, 103.00976° E), 6.09.2022 ;  parthenogenetic female from a roadside pond, Pahang (03.56735° N, 102.710508° E), 6.09.2022 .</p><p>The species was never fully described, so we provide a complete description for Malaysian populations.</p><p>Parthenogenetic female. In lateral view, body ovoid, compressed laterally, low in juveniles (Fig. 7A), moderately low in adults (Figs. 7B, 8A–F). Maximum height at mid-body or slightly before, height-to-length ratio around 0.6 in adults. Dorsal margin convex, postero-dorsal and postero-ventral angles broadly rounded. Posterior margin convex, ventral margin almost straight, antero-ventral angle rounded. Ventral margin (Figs. 7C, 8G) with 30–35 setae. About 8 anterior setae longer than others, next 10 setae short; setae in posterior half of the valve of moderate length. Postero-ventral angle (Figs. 7D, 8I–H) with one–four (in most specimens two) denticles, followed by about 20 setulae not organized into groups, the length of the denticle is less than the width of its base, distances between denticles approximately two widths of the base of the denticles. The same specimen can have different number of denticles on left and right valve. Valves in most specimens with a sculpture of well-developed narrow longitudinal lines (Figs. 8A, C, G). In some specimens, the valve lines are broad, and consist of overlapping tubercles (Fig. 8B).</p><p>Head relatively small, triangular-rounded in lateral view, rostrum short, pointing downwards (Fig. 9A). Compound eye larger than ocellus. Distance from tip of rostrum to ocellus 1.5 times longer than that between ocellus and eye.</p><p>Head shield with a maximum width behind mandibular articulation, with weakly developed tubercules (Fig. 7E). Rostrum short, broadly rounded, and posterior margin broadly rounded, slightly wavy. Three narrowly connected major head pores (Fig. 7F, 9B), median pore smaller than the others, located medially between the others. PP less than 0.5 IP. Lateral head pores located at less 1 IP distance from midline, at the level of anterior major head pore. Frontal head pore elongated, located between the bases of the antennules.</p><p>Labrum relatively large (Fig. 7G–I. 9C–D). Labral keel of moderate width (height/width ratio about 1.5), with a rounded or blunt apex. Anterior margin of keel convex, in some specimens with a pronounced blunt prominence in the upper portion, posterior margin without groups of setules.</p><p>Thorax twice as long as the abdomen. Dorsal surface of abdominal segments not saddle-shaped. Any abdominal projection absent.</p><p>Postabdomen (Fig. 7J–K, 9E–F) relatively short, subrectangular, moderately wide, weak narrowing in postanal portion. Length approximately 2.5 heights. Ventral margin almost straight to slightly convex. Distal margin convex, distal angle broadly rounded. The dorsal margin convex in postanal portion and concave in anal one, with distal part about 1.5 times longer than preanal one, anal and postanal portions of similar size. Preanal angle well-defined, soft postanal angle. Postanal margin with 2–3 large distal compound denticles followed by 3–4 groups of 2–4 small sharp denticles; length of longest denticles 1.5 times greater than width of the base of postabdominal claw. Anal portion with 2–3 broad groups of setulae. Postanal portion with 4–5 broad lateral groups of setulae, posteriormost setulae of each group of similar length with longest marginal denticles. Postabdominal claw (Fig. 8L) of moderate length, slightly shorter than preanal margin of postabdomen. Basal spine long, slender, about 0.35–0.5 times the length of the claw, a long setula located at its base.</p><p>Antennule (Fig. 7M, 9C) comparatively large, its tip almost reaching tip of rostrum, with three clusters of short setulae at anterior face. Length/width ratio c.a. 2.5. Antennular sensory seta slender, two times shorter than antennule, arising at about 2/3 distance from the base. Nine aesthetascs, two longest almost as long as antennule itself.</p><p>Antenna short (Fig. 7N, 9G). Antennal formula, setae 0–0–3/1–1–3, spines 1–0–1/0–0–1. Basal segment robust, branches short and robust. Coxal portion with two long setae. Basal segments of both branches almost two times longer than middle and apical segments. Seta arising from basal segment of endopod thin, reaching the end of the apical segment. Seta arising from middle segment of endopod shorter than apical setae. Both apical segments with three setae of similar thickness, one of them much shorter than two others. Spine on basal segment of exopodite longer than middle segment. Spines on apical segments slightly longer than respective segment.</p><p>Thoracic limbs: five pairs.</p><p>Limb I (Figs. 10 A-C) of moderate size. Epipodite oval, with a curved process longer than epipodite itself. Accessory seta short, about 1/3 length of ODL seta. IDL (Fig. 10B–C) with rudimentary seta 1 at its base. Seta 3 as long as ODL seta, seta 2 slightly shorter than seta 3. Seta 2 armed with large spines at the middle, seta 3 with single large spine, distal portion of both setae longer than mentioned spines. Endite 3 with four setae, inner seta (1) shorter than other setae (a–c). Endite 2 with seta d as long as setae a–c of endite 3, seta e long, almost as long as limb itself, seta f about 3/4 length of seta e. Endite 1 with two distally setulated 2-segmented setae (g–h) and a long flat seta (i) much longer than setae of endite 3. No naked inner setae (2–3) and sensillae on endites 1 and 2. Five–six rows of thin long setules on ventral face of limb. Two ejector hooks of unequal size. Maxillar process with a single seta.</p><p>Limb II (Fig. 10 D,E). Exopodite elongated, with a single seta twice as short as itself. Eight scraping spines armed with thin spinules: scrapers 1–5 long, increasing in length distally, scraper 3 slightly thicker than scrapers 2 and 4; scrapers 6–8 short, of similar size. Distal armature of gnathobase with four elements. Filter plate with seven setae, the two posterior ones considerably shorter.</p><p>Limb III (Fig. 10F). Epipodite oval, with a process as long as epipodite itself. Exopodite subrectangular, with six setae. Seta 3 being longest, seta 5 about 1/3 length of seta 3, seta 4 about 1/4 length of seta 3. Setae 1–4 plumose, seta 5 armed with thick setules in distal portion, seta 6 naked. Morphology of inner portion of the limb typical for the subgenus  Coronatella (Coronatella) .</p><p>Limb IV (Fig. 10G). Preepipodite setulated; epipodite oval, with a process longer than epipodite itself. Exopodite rounded, with six setae. Seta 3 longest, setae 1 and 2 about 4/5 length of seta 3, seta 5 about 1/3 length of seta 3, setae 4 and 6 short. Setae 1–4 flattened, plumose, setae 5 and 6 slender, without setulae. Morphology of inner portion of the limb typical for the subgenus C. ( Coronatella).</p><p>Limb V (Fig. 10H). Preepipodite setulated, epipodite oval, with a process 1.5 times longer than exopodite. Exopodite oval, slightly bilobed, with four plumose setae, evenly decreasing in size basally, seta 4 four times shorter than seta 1. Inner limb portion as broad rounded lobe, with setulated inner margin.At inner face, two short setae, one 1.5 times longer than another. Filter plate absent.</p><p>Ephippial female, male. Unknown.</p><p>Size. In studied material, juvenile female II length 0.19–0.21 mm, height 0.12–0.13 mm; adult parthenogenetic female length 0.24–0.31 mm, height 0.15–0.19 mm.</p><p>Differential diagnosis.  Coronatella (C.) acuticostata belongs to the  monacantha -clade of C. ( Coronatella), and shares main character of the group, presence of denticles on posteroventral margin of valves (Sinev 2020). Known species of the group include Neotropical  C. (C.) monacantha (Sars, 1901) and  C. (C.) undata Sousa, Elmoor-Loureiro &amp; Santos, 2015, and African  C. (C.) hardingi (Brehm, 1957) .  Coronatella (C.) acuticostata differs from both Neotropical species in a variable number of denticles on the posteroventral angle of valves –  C. (C.) monacantha always has a single denticle, while  C. (C.) undata always has two denticles spaced very close to each other (see Sousa et al. 2015).  Coronatella (C.) hardingi (see Van Damme 2016) has uniformly convex, not wavy posterior margin of valves, shorter basal spine of postabdomen, and 1 or 2 narrower denticles on posteroventral angle of valves (if there are two denticles, they are spaced very close to each other), and longer antennal spines, spine of basal segment of exopodite reach to the middle of apical segment, and apical spines 1.5 times longer, than apical segments.</p><p>Taxonomic notes.  Coronatella (Coronatella) acuticostata was described from Sumatra (Sars 1903a) as  Alona acuticostata . Later, Stingelin (1905) described Thailand populations with three denticles on the posteroventral angle of valves as a special variety,  Alona acuticostata var. tridentata . During the XXth century, this taxon was accepted as a synonym of  Alona monacantha Sars, 1901 (Smirnov 1971; Idris 1983; Maiphae et al. 2008). However, recent studies of the  monacantha -group (Sinev 2004; Sousa et al. 2015; Van Damme 2016) led to a re-evaluation of the status of Neotropical and African species of this group. Our data fully confirms the independent status of  C. (C.) acuticostata, suggested during previous studies of Indo-Malaysian fauna (Sinev &amp; Yusoff 2015; Sinev 2016).</p><p>Detailed morphological study of  Coronatella (Coronatella) acuticostata is conducted for the first time. The species was described from Sumatra, so the studied populations are distributed quite close to the type locality. Our data confirm both an independent status of the species and its position within the  monacantha -clade. The  monacantha -group is distributed in Neotropical, Afrotropical and Indo-Malaysian Provinces. Recent revisions of the  monacantha -group (Sousa et al. 2015; Van Damme 2016) and our data once again fully confirm the “Frey’s non-cosmopolitanism paradigm” (Frey 1982, 1987b) for  Chydoridae . Taxonomic status of the  monacantha -clade populations recorded from India and Sri Lanka is unclear at the moment, but they probably belong to  Coronatella (Coronatella) acuticostata as well. Interestingly, the most widely distributed tropical  Aloninae clades are also present in Australia, but not the  monacantha -group (Smirnov &amp; Timms 1983). The only Australian species of C. ( Coronatella) is  C. (C.) novaezealandiae (Sars, 1904) (Sinev 2022) .</p><p>Distribution and ecology.  Coronatella acuticostata is a littoral species, associated with vegetation, distributed in Indo-Malaysian region. Our data suggests that all earlier records of  Alona monacantha from South-East Asia (see Koronchinsky 2013) refer to С (С.)  acuticostata . Taxonomic status of  monacantha -group populations from India remains unclear, as the level of present descriptions is not sufficient to clarify the taxonomic status of local populations.</p></div>	https://treatment.plazi.org/id/03F2AF08FFBDFFCFC7D2256FFEB7FB63	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFB8FFCFC7D2265DFE53F800.text	03F2AF08FFB8FFCFC7D2265DFE53F800.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Karualona serrulata Van Damme, Maiphae & Sa-adrit 2013	<div><p>Karualona serrulata Van Damme, Maiphae &amp; Sa-adrit, 2013</p><p>Fig. 10I–L</p><p>Sinev &amp; Korovchinsky 2013: Fig. 2 H–K ( Karualona sp.); Van Damme et al. 2013: 182–186, Fig 4–8; Sinev 2016: 473, Fig. 11I–K.</p><p>Material examined:   A single parthenogenetic female from a lake full of lotus, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.63171&amp;materialsCitation.latitude=2.8582" title="Search Plazi for locations around (long 101.63171/lat 2.8582)">Paya Indah Wetland</a>, Selangor (2.85820° N, 101.63171° E), 03.09.2022  .</p><p>This is the first record for Malaysia.  Karualona serrulata is habitually similar to other East Asian species of the genus (Fig. 10I), but it can be easily distinguished from them by a peculiar morphology of the posteroventral angle of valves (Fig. 10J). It also differs from most common species of the region,  K. fatimae Sinev &amp; Semenyuk, 2023 (earlier recorded as  K. karua King, 1853) in the absence of a spinule on anterior margin of labrum (Fig 10K) and in a well-developed basal spine of the postabdominal claw (Fig. 10L). For detailed description see Van Damme et al. (2013).</p><p>Karualona serrulata is a rare species, an endemic of South-East Asia, so far known from South and North-East Thailand, Vietnam and Laos (Sinev 2016). The species is found in swamps and shallow lakes, littoral species, associated with vegetation.</p></div>	https://treatment.plazi.org/id/03F2AF08FFB8FFCFC7D2265DFE53F800	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
03F2AF08FFA7FFD7C7D22526FAE7FD0F.text	03F2AF08FFA7FFD7C7D22526FAE7FD0F.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Chydorus obscurirostris subsp. tasekberae Frey 1987	<div><p>Chydorus obscurirostris tasekberae Frey, 1987</p><p>Fig. 11–14</p><p>Idris &amp; Fernando 1981a: 243–246, Figs. 44–46 (faviformes); Idris,1983: (faviformes); Frey 1987a: 369–371, Fig. 78–85, 88– 115, 130–143; Kotov 2006: Fig. 4a –ж.</p><p>Material examined:   over 30 parthenogenetic females from several localities in  Chini Lake, Pahang state  .</p><p>Description. Parthenogenetic female.</p><p>Body shape is typical of the genus  Chydorus, oval in juveniles (Fig. 11A) and rounded in adults (Fig. 11B–C, 12A–D) in lateral view, height/length ratio about 0.9, maximum height at midline. In frontal and posterior view (Fig. 12E–F, 13A), body subtriangular, with weakly convex dorsal surface and moderately developed egg locules, which narrow significantly in the ventral half. Valves and head shield completely covered by numerous honeycomb-like meshes, not organized into ridges or collars (Fig. 13B–C). Height of mesh walls of variable height, about 20 µm in highest meshes. Mesh walls edge with irregularly spaced, very short dense setulae. Surface of valves and head shield inside the meshes with a characteristic, irregular spider web-like patterns of tiny ridges of variable height. Valves. Anterior angle broadly rounded, with a submarginal flange at inner side. Ventral margin of valves with about 50 setae; 10–12 anterior setae very thin, short, located on the inner side of valves close to margin, followed by about ten very short setae located maginally. Posterior group consists of about 28 long setae, armed bilaterally with long setules (Fig. 11D), located on inner side of valve; maximum length of setae in the middle of the group. Two–three posteriormost setae straight, thick, spine-like. Postero-ventral angle without denticles. Valves covered by a honeycomb-like polygonal sculpture, about 120 cells per valve. Largest cells are located at egg locules, at the border with head shield, size of cell gradually decreases toward outer margins of valves.</p><p>Head with a short rostrum, protruding downward and posteriorly (Fig. 11E, 13B). Length of rostrum about 1.5 length of antennule. Ocellus 1.5 times smaller than eye. Head shield large, with maximum width at the middle of posterior portion; its posteriormost portion widely oval (Fig. 12F, 13A). Rostrum (Fig. 11E, 13B) wide triangular in frontal view, apex divided into two small asymmetric lobes, lateral meshes obscure lateral margins of rostrum. Head shield covered by a honeycomb-like polygonal sculpture of less than 100 asymmetrically spaced, irregularly varying in size meshes (Fig. 13A). Largest meshes are located at posterior margin of head shield. Two major head pores (Fig. 13D), each at the break of mesh wall between two meshes on surface of head shield. PP is about 1 IP. Lateral head pores minute (Fig. 13E), located asymmetrically, close to midline of head shield, at the middle between anterior and posterior major head pores. Labrum with a small, oval labral keel (Fig. 11F) having a rounded apex. Height of keel about 1.5 widths. Anterior margin of labral keel convex, posterior margin weakly convex.</p><p>Postabdomen (Fig. 11G, 13F) short, rather narrow, weakly narrowing distally. Length about 3.5 heights. Ventral margin clearly concave. Base of claws delimited from the distal margin by a clear incision. Distal margin convex, distal angle rounded. Dorsal margin straight in postanal portion and weakly concave in the anal one. Distal part of postabdomen about 1.5 times longer than the preanal portion, postanal portion two times shorter than anal portion. Preanal angle well-expressed, triangular, well-prominent; postanal angle not defined. Preanal margin unequally concave. Dorsal margin with about eight narrow sharp denticles and 2–3 broad groups of short setules in anal portion. Length of longest denticles slightly greater than width of base of postabdominal claw. A row of 7–8 lateral groups of short setulae, the number of setulae in the group increases basally.</p><p>Postabdominal claw (Fig. 13F) slender, weakly curved, slightly shorter than preanal portion of postabdomen, with a distinctive pecten of setules on dorsal margin. The basal portion of pecten consists of about 10 short spinules, distal portion of about 15 longer setules. Several long setulae located ventrally near the claw end. Two basal spines; distal spine length 0.25 length of the claw, proximal spine two times shorter.</p><p>Antennula (Fig. 11H) of moderate size; length about two widths. Antennular seta thin, about half length of antennule, arising at 2/3 distance from the base. Nine terminal aesthetascs, six of them about 2/3 length of antennule, three about 1/3 length of antennule.</p><p>Antenna is relatively short (Fig. 11I–J). Antennal formula: setae 0-0-3/0-1-3; spines 1-0-1/0-0-1. Branches relatively short; proximal segment of both branches 1.5 times longer and thicker than two others. Seta arising from middle segment of endopodite as long as most apical setae. Apical segment of endopodite with a single subapical seta and two apical setae, one of apical setae two times shorter and thinner than two others. Apical segment of exopodite with a single subapical seta and two apical setae of similar size. All antennal spines very short.</p><p>Thoracic limbs: five pairs.</p><p>Limb I of moderate size (Fig. 14A–C). Epipodite oval, with process 1.5 times longer than exopodite itself. ODL with two setae, one of them very small. IDL with three setae and several clusters of setules. IDL (Fig.14 B-C) with setae 1–2 thin, about 1/3 and 1/2 length of longest ODL seta, respectively; seta 3 thick, strong, claw-like, little shorter than longest ODL seta, armed with about 20 hard setulae in the distal part. Base of IDL seta 3 two times wider than base of setae 1–2. A small sensillum located near bases of IDL setae 2–3. Endite 3 with four setae, inner seta (1) (Fig.14A) shorter than outer setae (a–c) (Fig. 14B). Endite 2 with seta d (Fig.14B) slightly longer than setae of endite 1, setae e–f (Fig.14A) almost as long as limb body, seta e slightly longer than seta f, and an inner seta (2) on anterior face of limb. Endite 1 with three two-segmented setae (g-i) (Fig.14B), flattened shorter seta i close to limb base (Fig.14A), and an inner seta armed with spinules (3) on anterior face of limb. Six-seven rows of thin long setules on ventral face of limb. Two ejector hooks, first one slightly shorter than the other one.</p><p>Limb II subtriangular (Fig. 14D). Exopodite oval, with seta two times longer than exopodite. Eight scraping spines; spines 1–3 long, slightly decreasing in size basally, armed with fine spinules; spines 4–8 short, with length of setae 4–5 and 7–8 evenly decreasing basally, seta 6 much thinner and shorter than neighbours; seta 5 thicker than others, armed with thick spinules, seta 4 and 6–8 armed with spinules of moderate size. An elongated sensillum located between spines 3 and 4. Distal armature of gnathobase with four elements. Filter plate II with eight setae, the two posteriormost members much shorter than others, about 1/2 and 2/3 lengths of other setae, respectively.</p><p>Limb III (Fig. 14E–F). Epipodite oval, without projection. Exopodite subquadrangular, with three lateral (1–3) and four terminal (4–7) setae. Seta 4 being longest; setа 6 slightly shorter than seta 4, setae 1–2 and 7 subequal in length, about 2/3 length of seta 4, setae 3 and 5 about 1/2 length of seta 4. Setae 1–5 flattened, plumose; seta 6 slender, with row of very long, thick setules at the middle and small spinules in distal portion; seta 7 slender, naked. Distal endite with 3 scraping setae (1–3) and two small sensillae located between their bases, setae 1–2 (Fig.14E) slender, of similar length, with small denticles in distal part, seta 3 (Fig.14F) small and thin, three times shorter than setae 1–2. Basal endite with six plumose setae (a–f) (Fig.14E) slightly increasing in size basally. Four pointed inner setae (4–7) (Fig.14F) increasing in size basally; an elongated sensillum near the base of seta 4. Distal armature of gnathobase (Fig.14F) with four elements: one very large sensillum with curved distal portion, strongly geniculated seta, short spine and sensillum of moderate size. Filter plate III with eight setae.</p><p>Limb IV (Fig. 14G–H). Pre-epipodite setulated; epipodite elongated, with process longer than epipodite itself. Exopodite rounded with seven setae; seta 1 being longest, length of setae decreases evenly from seta 1 to seta 4; seta 4 about 2/3 length of seta 1; seta 5 and 7 about 1/3 length of seta 1; seta 6 about 1/2 length of seta 1. Setae 1–5 flat, plumose; seta 6 setulated unilaterally in basal part, seta 7 naked. Inner portion of limb IV with four setae. Scraping seta (1) slender; three flaming-torch setae (2–4) slightly increasing in size basally, each armed with 7–8 thick long setulae. Small sensilla located near base of seta 3. Four inner setae (a–d) increasing in length basally. Gnathobase with one 2–segmented setae, a small hillock distally, and two small sensillae. Filter plate with six setae.</p><p>Limb V (Fig. 14I–J). Pre-epipodite setulated; epipodite oval, with two processes protruding at the different sides of exopodite, one as long as epipodite, another two times longer. Exopodite ovoid, with four setae, length of setae 1–3 evenly decreasing basally, seta 3 about 2/3 length of seta 1, seta 4 as long as seta 3. Setae 1–3 plumose, seta 4 bilaterally armed with thick setulae in distal poirtion. Two small hillocks with thick setulae located on basal side of exopodite near seta 4. Inner lobe long, narrow, with setulated inner margin. At inner face, two setae of similar length, in distal portion armed unilaterally with thick setulae. Filter plate with four setae.</p><p>Ephippial female and male unknown.</p><p>Size. Length of females (excluding honeycomb meshes) in studied material was up to 0.38 mm, height up to 0.3 mm; length of smallest juvenile female 0.24 mm, height 0.2 mm. According to Frey (1987a), length of adult females from Bera Lake was 0.28–0.39 mm.</p><p>Taxonomic notes. The morphology of thoracic limbs for most species of the  faviformis -group was described only by Frey (1987a); a full set of drawings was provided only for  C. obscurirostris obscurirostris Frey, 1987 . Frey (1987a) did not find any significant differences between the species of the  faviformis -group in limb morphology, except in the morphology of IDL seta. Comparison of limb morphology of C. o.  obscurirostris (Frey, 1987a: fig. 86– 94) with that in our populations reveals that C. o. tasekberae has a more robust seta 1 of IDL of limb I. Despite Frey (1987a) did not give information on epipodite morphogy in  C. obscurirostris, our study shows unusual structure of epipodite V in C. o. tasekberae, which has been never reported for any other  Chydorus taxa. Within  Cladocera, doubled epipodite process occurs very rarely: to date, it was observed in limb I of rare African  Aloninae Matralona simoneae (Dumont, 1981) (Van Damme &amp; Dumont 2009) and in thoracic limb I of  Bosminopsis Richard, 1895 (see Garibian et al. 2021; Kotov &amp; Garibian 2021).</p><p>The only detailed description of thoracic limbs for the  faviformis -group was produced for  C. izvekovae Sinev, Novichkova &amp; Chertoprud, 2022 (Sinev et al. 2022) recently described from North-East Russia. In  Chydorus, differences in the thoracic limb morphology between species of the same group are generally either absent(Klimovsky &amp; Kotov 2015), or sometimes closely related species, like these of the eurynotus -group, differ by proportions of IDL setae (Sinev 2014). However, there are numerous differences between limbs of  C. obscurirostris tasekberae and  C. izvekovae, which are summarized in Table 1. These two species differ in morphology of IDL setae of limb I, in proportions of limb I endites setae, in morphology of scrapers of limb II, and in proportions of setae of exopodite III.  Chydorus izvekovae has epipodite V with single process, as common for the majority of  Chydoridae .</p><p>Recent studies of the genus  Chydorus (Sinev 2014; Sousa et al. 2024) revealed that two species, South-East Asian  C. breviceps (Stingelin, 1905) and African  C. tilhoi Rey &amp; Saint-Jeans, 1969 have numerous differences from the majority of the genus in outer morphology, morphology of head pores, postabdomen and appendages, and probably should be placed into a separate genus. These authors did not discuss taxonomic status of the  faviformis - group. Morphology of thoracic limbs of  C. obscurirostris tasekberae (our data) and  C. izvekovae (Sinev et al. 2022) is generally similar to that of  C. sphaericus group (see Klimovsky &amp; Kotov 2015; Sousa et al. 2024). While outer morphology of  faviformis -group species is outstanding, the group shares main characters of  Chydorus s. str. in morphology of head pores, postabdomen, labrum and head appendages, and its position within the genus is wellsupported.</p><p>Distribution and ecology.  Chydorus obscurirostris tasekberae Frey, 1987 was described from Bera Lake in Peninsular Malaysia (Frey 1987a). It was recorded in North-East Thailand (Maiphae et al. 2008; Kotov 2006) and Vientiane Province, Laos (Kotov et al. 2013), but the latter record is doubtful, as provided illustrations show specimens with central meshes of the valves only slightly larger than meshes near valve edges. In Malaysia,  C. obscurirostris tasekberae is found only in Bera Lake and Chini Lake among macrophytes, it is quite rare there.</p></div>	https://treatment.plazi.org/id/03F2AF08FFA7FFD7C7D22526FAE7FD0F	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.		MagnoliaPress via Plazi	Sinev, Artem Y.;Dadykin, Ivan A.;Umi, Wahidah A. D.;Yusoff, Fatimah M.	Sinev, Artem Y., Dadykin, Ivan A., Umi, Wahidah A. D., Yusoff, Fatimah M. (2025): New data on Cladocera (Crustacea: Branchiopoda) of Peninsular Malaysia. Zootaxa 5604 (3): 255-284, DOI: 10.11646/zootaxa.5604.3.3, URL: https://doi.org/10.11646/zootaxa.5604.3.3
