identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03E5B718FFB2A31BC2B3F926FE4BF947.text	03E5B718FFB2A31BC2B3F926FE4BF947.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pseudomystus stenomus	<div><p>Pseudomystus stenomus (Valenciennes in Cuvier &amp; Valenciennes, 1840)</p><p>(Fig. 1)</p><p>Bagrus stenomus Valenciennes in Cuvier &amp; Valenciennes, 1840: 415 (type locality: Java); Bleeker, 1858: 165; Roberts, 1993: 27, Fig. 61.</p><p>Leiocassis ellenriederii Bleeker, 1860:10 (type locality: Lahat, Sumatra).</p><p>Leiocassis stenomus: Bleeker, 1862 –63: 54, Pl. 67 Fig. 3; Weber &amp; de Beaufort, 1913: 355 (in part); Jayaram, 1968: 364 (in part).</p><p>Liocassis breviceps Regan, 1913: 551 (type locality: Deli [= Medan], Sumatra; in part)</p><p>Leiocassis breviceps (non Regan, 1913): Weber &amp; de Beaufort, 1913: 361 (in part); Jayaram, 1968: 363 (in part).</p><p>Pseudomystus breviceps (non Regan, 1913): Ng &amp; Rachmatika, 1999: 178 (in part); Ng &amp; Lim, 2005: 16 (in part); Ferraris, 2007: 103 (in part); Lim &amp; Ng, 2008: 45 (in part); Kottelat, 2013: 265 (in part).</p><p>Pseudomystus stenomus: Tan &amp; Ng, 2000: 281; Ng &amp; Lim, 2005: 17 (in part); Lim &amp; Ng, 2008: 46 (in part); Tan &amp; Kottelat, 2009: 20; Grant, 2009: 16, Figs. 1 –5, 8; Kottelat, 2013: 266; Iqbal et al., 2018: 108, Figs. 434–435, 437.</p><p>Material examined. RMNH 2986, holotype, 69.1 mm SL; Java . – BMNH 1889.11.12.65, paralectotype of Liocassis breviceps, 67.2 mm SL; Sumatra : Deli [=Medan]. – ZRC 44163, 50, 54.4–82.6 mm SL; ZRC 44166, 21, 29.0– 42.4 mm SL; Sumatra: Jambi, Sungai Alai. – ZRC 46251, 18, 25.2–42.8 mm SL; Sumatra: Jambi .</p><p>5 mm</p><p>A B</p><p>Fig. 2. Dorsal views of nuchal plates showing shape in: a, Pseudomystus stenomus (ZRC 44163, 58.9 mm SL illustrated); b, P. breviceps, P. flavipinnis, and P. nuchalis ( P. breviceps, ZRC 27674, 54.2 mm SL illustrated). Scale bar represents 5 mm.</p><p>Diagnosis. Pseudomystus stenomus is distinguished from all congeners except for P. breviceps, P. flavipinnis, P. moeschii, P. myersi, P. nuchalis, P. tuberosus, and P. vaillantii in having a colour pattern of pale yellow patches on the body (vs. uniformly-coloured body, or with either pale transverse bands or pale longitudinal stripes). It differs from P. breviceps, P. flavipinnis, and P. nuchalis in having a narrower nuchal plate with slightly concave lateral margins (vs. broader nuchal plate with straight or slightly convex margins; Fig. 2), and further differs from P. breviceps in having a slenderer caudal peduncle (7.8–9.7% SL vs. 9.2–11.5), from P. flavipinnis in having a broader snout (width 56–59% HL vs. 48–53; Fig. 3), adipose fin more anteriorly positioned relative to the anal fin (adipose-fin origin at vertical through anal-fin origin vs. posterior to vertical) and the pale yellow patches on the body never coalescing to form bands (vs. frequently coalescing to form irregular bands), and from P. nuchalis in lacking (vs. having) a nuchal concavity (compare Figs. 1 and 4). Pseudomystus stenomus is distinguished from P. moeschii in lacking (vs. having) a supracleithral process, and from P. myersi in having an adipose fin with a shorter base (12.7–17.4% SL vs. 31.5–34.1) whose posterior insertion is separate from (vs. adnate to) the dorsal procurrent caudal-fin rays. It differs from P. tuberosus in having an evenly sloping (vs. strongly humped) predorsal profile, the absence (vs. presence) of rounded tubercles on the head and flanks, an adipose fin with a shorter base (12.7–17.4% SL vs. 23.3–26.1) and a deeper caudal peduncle (7.8–9.7% SL vs. 5.5–6.0), and from P. vaillantii in having a shorter head (21.7–26.2% SL vs. 27.0–29.0) and adipose-fin base (12.7–17.4% SL vs. 20.3–26.7).</p><p>Description. Morphometric data as in Table 1. Head depressed; dorsal profile evenly sloping or very gently convex. Ventral profile almost straight. Snout broadly rounded when viewed dorsally, width 56–59% HL. Bony elements of dorsal surface of head covered with thin skin. Midline of cranium with fontanelle extending from behind snout to just anterior to level of posterior orbital margin. Supraoccipital process of moderate width, with gently converging sides and notched tip; in contact with nuchal plate. Eye ovoid, horizontal axis longest, subcutaneous; located entirely in dorsal half of head. Gill openings wide, extending from post-temporal to beyond isthmus. Gill membranes free from isthmus. First branchial arch with 3+7 (3), 3+8 (1) or 4+8 (2) gill rakers.</p><p>Mouth subterminal. Oral teeth small and villiform, in irregular rows on all tooth-bearing surfaces. Premaxillary tooth band rounded, of equal width throughout. Dentary tooth band much narrower at symphysis than premaxillary tooth band, tapering laterally. Vomerine tooth band unpaired, continuous across midline; smoothly arched along anterior margin, tapering laterally to point extending posteriorly past level of premaxillary band; band width at midline narrower than premaxillary band, widening laterally and then tapering to sharp point postero-laterally.</p><p>Barbels in four pairs. Nasal barbel slender, extending to middle of pectoral-fin base. Maxillary barbel slender, extending to level of midpoint between base of last pectoral-fin ray and pelvic-fin origin. Inner mandibular-barbel origin close to midline, thicker and longer than nasal barbel, extending to base of last pectoral-fin ray. Outer mandibular barbel originating postero-lateral of inner mandibular barbel, extending beyond base of last pectoral-fin ray.</p><p>Body terete, becoming more compressed toward caudal peduncle. Dorsal profile gently convex from tip of snout to origin of dorsal fin, sloping gently ventrally from origin of dorsal fin to end of caudal peduncle. Ventral profile slightly convex to anal-fin base, then sloping slightly dorsally to end of caudal peduncle. Skin smooth. Lateral line complete, mid-lateral in position. Vertebrae 18+20=38 (2), 19+20=39 (5), 20+19=39 (2), 19+21=40 (3), 20+20=40 (8), 20+21=40 (5), 19+22=41 (2), 21+20=41 (3), or 21+21=42 (1).</p><p>Dorsal fin with spinelet, spine, and 5,i (4), 6 (1), 6,i (15) or 7 (10) rays. Origin of dorsal fin anterior to mid-body, at about one-third of body length. Dorsal fin distal margin convex, usually with anterior branch of fin rays longer than other branches. Dorsal fin spine of moderate length, gently curved, slender, its posterior edge with 4–7 small, retrorse serrations. Nuchal plate narrowly triangular, with slightly concave lateral margins. Pectoral fin with stout spine, sharply pointed at tip, and 6 (1), 6,i (11) or 7 (18) rays. Anterior spine margin smooth; posterior spine margin with 9–14 retrorse serrations along entire length. Pectoral fin margin straight anteriorly, convex posteriorly. Humeral process narrowly triangular, with slightly concave dorsal margin, extending for half of pectoral-spine length. Pelvic fin origin at vertical posterior to posterior end of dorsal-fin base, with i,5 (30) rays, its margin slightly convex; tip of adpressed fin not reaching anal-fin origin. Anal and urogenital opening located at vertical through posterior third of adpressed pelvic fin. Males with elongate genital papilla reaching to anal-fin base. Adipose fin with convex margin for entire length, with deeply-incised posterior portion, origin separate from base of last dorsal-fin ray; fin-base of moderate length, spanning one-third of postdorsal distance. Anal fin origin at vertical through origin of adipose fin, with v,9 (1), v,10,i (2), vi,9,i (8), v,10,ii (1), v,11,i (1), vii,9,i (1), vi,10,i (13), vi,11,i (2) or vii, 10,i (1) rays, its posterior margin curved. Caudal peduncle of moderate depth. Caudal fin deeply forked, with i,7,8,i (30) principal rays; upper and lower lobes slender, pointed. Procurrent rays extending anterior to fin base, with evenly-sloping anterior margins.</p><p>Colour. In 70% ethanol: head and body dark brown above, fading to pale yellow on ventral third of head and body. Abdomen pale yellow, lateral margins speckled with brown melanophores. Faint, irregularly-shaped yellowish, patches on either side of nape. Single faint ovoid yellowish patch on sides of body behind tympanic region and below dorsal fin (absent in some individuals). Series of paired faint, irregularly-shaped yellowish patches on body: first series above and below lateral line on interdorsal region (between dorsal and adipose fins), second series above and below lateral line below posterior portion of adipose-fin base, third series on dorsal and ventral procurrent caudal-fin rays (absent in some individuals). Dorsal fin with dark brown base and dark brown submarginal bar. Pectoral and pelvic fins with dark brown base and scattered brown melanophores on middle third of fin rays, forming diffuse submarginal brown band. Adipose fin dark brown, with narrowly ellipsoid yellowish patch on dorsal surface at anterior origin (absent in some individuals), its posterior margin hyaline. Anal fin hyaline with both a dark brown base and diffuse brown melanophores on proximal three-quarters of fin rays. Caudal fin hyaline, with diffuse brown melanophores on fin rays.</p><p>Distribution. Pseudomystus stenomus is known from an unspecified river drainage (very likely either the Ciliwung or</p><p>Cisadane drainage) in western Java and the Deli and Batang Hari drainages in Sumatra (Fig. 5). It is likely to be found in river drainages between these two systems in Sumatra and Java (e.g., the Indragiri, Musi, and Tulang Bawang river drainages in Sumatra). The species, however, is likely extirpated in Java (Ng, 2020) .</p></div>	https://treatment.plazi.org/id/03E5B718FFB2A31BC2B3F926FE4BF947	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	Ng, Heok Hee	Ng, Heok Hee (2025): Clarifying the identity of Pseudomystus stenomus, with the description of a new species of Pseudomystus from Borneo (Actinopterygii: Bagridae). Raffles Bulletin of Zoology 73: 318-335, DOI: 10.26107/RBZ-2025-0023
03E5B718FFB6A316C2FEF97BFD82F7C7.text	03E5B718FFB6A316C2FEF97BFD82F7C7.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pseudomystus breviceps (Regan 1913)	<div><p>Pseudomystus breviceps (Regan, 1913)</p><p>(Fig. 6)</p><p>Liocassis breviceps Regan, 1913: 551 (type locality: Deli [= Medan], Sumatra; in part)</p><p>Liocassis stenomus (non Valenciennes in Cuvier &amp; Valenciennes, 1840): Duncker, 1904: 305.</p><p>Leiocassis breviceps: Weber &amp; de Beaufort, 1913: 361 (in part); Jayaram, 1968: 363 (in part).</p><p>Leiocassis stenomus (non Valenciennes in Cuvier &amp; Valenciennes, 1840): Weber &amp; de Beaufort, 1913: 355 (in part); Jayaram, 1968: 364 (in part); Suvatti, 1981: 90.</p><p>Pseudomystus breviceps: Ng &amp; Rachmatika, 1999: 178 (in part); Ng &amp; Lim, 2005: 16 (in part); Ferraris, 2007: 103 (in part); Lim &amp; Ng, 2008: 45 (in part); Kottelat, 2013: 265 (in part).</p><p>Pseudomystus stenomus (non Valenciennes in Cuvier &amp; Valenciennes, 1840): Smith, 1945: 381, Fig. 54; Ng &amp; Tan, 1999: 359; Kulabtong et al., 2015: 689; Zakaria-Ismail et al., 2019: 177, Fig. 243; Azmai et al., 2020: 81; Panitvong, 2022: 429; Ahmad et al., 2023: 105; Aqmal-Naser et al., 2024: 55.</p><p>Material examined. BMNH 1889.11.12.64, lectotype (here designated), 76.0 mm SL; Sumatra: Deli [= Medan] . – ZRC 51595, 1, 57.6 mm SL; Thailand: Chantaburi, Pong Nam Ron area . – CMK 5598, 2, 48.8–52.2 mm SL; Thailand: Surat Thani Province, Cheow Lan [= Rajjaprabha] Dam, Khlong Sang . – ZRC 23494–23496, 3, 33.6–64.6 mm SL; ZRC 24510, 1, 49.5 mm SL; ZRC 38735, 2, 40.9–48.6 mm SL; Malaysia: Terengganu, Sungai Sekayu, outside <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.95861&amp;materialsCitation.latitude=4.9652777" title="Search Plazi for locations around (long 102.95861/lat 4.9652777)">Sekayu Waterfall Park</a>, 4°57′55″N 102°57′31″E . – ZRC 27673–27682, 10, 38.8–96.5 mm SL: Malaysia: Selangor, Sungai Bernam headworks . – ZRC 55862, 2, 45.5–50.1 mm SL; Malaysia: Pahang, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.211105&amp;materialsCitation.latitude=3.6944444" title="Search Plazi for locations around (long 102.211105/lat 3.6944444)">Sungai Lompat</a>, 3°41′40″N 102°12′40″E . ZRC 55870, 1, 70.1 mm SL; Malaysia: Pahang, Pahang River drainage, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=102.225&amp;materialsCitation.latitude=3.7083335" title="Search Plazi for locations around (long 102.225/lat 3.7083335)">Sungai Lompat in Krau Game Reserve</a>, 3°42′30″N 102°13′30″E . – ZRC 66524, 1, 67.0 mm SL; Malaysia: Pahang, Rompin River drainage, Bukit Ibam, Kampung Aur . – ZRC 40184, 15, 24.0– 75.9 mm SL; Malaysia: Pahang, Sungai Belat, 26 km from Kuantan . – ZRC 22047, 6, 28.0– 35.4 mm SL; Malaysia: Pahang, stream immediately west of the junction of Kuantan–Segamat road and Kuantan – Kuala Lumpur road . – ZRC 7586, 1, 88.6 mm SL; Malaysia: Johor, Segamat . – ZRC 23102, 1, 34.4 mm SL; Malaysia: Johor, Muar River drainage, Sungai Tui, along Muar – Labis road . – ZRC 21476, 2, 39.6–40.9 mm SL; Malaysia: Johor, Endau River drainage, Sg. Jasin . – ZRC 42760, 22, 29.0– 76.8 mm SL; ZRC 42784, 30, 19.7–82.4 mm SL; ZRC 44195, 3, 36.2–39.5 mm SL; ZRC 46132, 16, 22.8–40.1 mm SL; ZRC 56899, 9, 31.2–85.6 mm SL; Malaysia: Johor, Sungai Kahang and tributary, about 44.4 km from Mersing turnoff to <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.52639&amp;materialsCitation.latitude=2.0655556" title="Search Plazi for locations around (long 103.52639/lat 2.0655556)">Kluang</a> just before side road to <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.52639&amp;materialsCitation.latitude=2.0655556" title="Search Plazi for locations around (long 103.52639/lat 2.0655556)">Endau Rompin Taman Negara</a>, km 96 from <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.52639&amp;materialsCitation.latitude=2.0655556" title="Search Plazi for locations around (long 103.52639/lat 2.0655556)">Mersing</a> to <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.52639&amp;materialsCitation.latitude=2.0655556" title="Search Plazi for locations around (long 103.52639/lat 2.0655556)">Batu Pahat</a>, 2°3′56″N 103°31′35″E .</p><p>Diagnosis. Pseudomystus breviceps is distinguished from all congeners except P. flavipinnis, P. moeschii, P. myersi, P. nuchalis, P. stenomus, P. tuberosus, and P. vaillantii in having a colour pattern of pale yellow patches on the body (vs. a uniformly brown body, or with either pale yellow transverse bands or longitudinal stripes). It differs from P. flavipinnis in having a broader snout (54–60% HL vs. 48–53; Fig. 3), adipose fin more anteriorly positioned relative to the anal fin (adipose-fin origin at vertical through anal-fin origin vs. posterior to vertical) and the pale yellow patches on the body never coalescing to form bands (vs. frequently coalescing to form irregular bands), from P. nuchalis in lacking (vs. having) a nuchal concavity (compare Figs. 4 and 6), and from P. stenomus in having a broader nuchal plate with straight or slightly convex margins (vs. narrower nuchal plate with slightly concave lateral margins; Fig. 2) and a deeper caudal peduncle (9.2–11.5% SL vs. 7.8–9.7). Pseudomystus breviceps is distinguished from P. moeschii in lacking (vs. having) a supracleithral process, and from P. myersi in having an adipose fin with a shorter base (15.1–19.8% SL vs. 31.5–34.1) whose posterior insertion is separate from (vs. adnate to) the dorsal procurrent caudal-fin rays. It differs from P. tuberosus in having an evenly sloping (vs. strongly humped) predorsal profile, the absence (vs. presence) of rounded tubercles on the head and flanks, an adipose fin with a shorter base (15.1–19.8% SL vs. 23.3–26.1) and a deeper caudal peduncle (9.1–11.5% SL vs. 5.5–6.0), and from P. vaillantii in having a shorter head (22.8–26.2% SL vs. 27.0–29.0) and adipose-fin base (15.1–19.8% SL vs. 20.3–26.7).</p><p>Description. Morphometric data as in Table 1. Head depressed; dorsal profile evenly sloping or slightly convex. Ventral profile almost straight. Snout broadly rounded when viewed dorsally, width 54–60% HL. Bony elements of dorsal surface of head covered with thin skin. Midline of cranium with fontanelle extending from behind snout to beyond level of posterior orbital margin. Supraoccipital process of moderate width, with gently converging sides and notched tip; in contact with nuchal plate. Eye ovoid, horizontal axis longest, subcutaneous; located entirely in dorsal half of head. Gill openings wide, extending from post-temporal to beyond isthmus. Gill membranes free from isthmus. First branchial arch with 3+7 (3) or 3+8 (1) gill rakers.</p><p>Mouth subterminal. Oral teeth small and villiform, in irregular rows on all tooth-bearing surfaces. Premaxillary tooth band rounded, of equal width throughout. Dentary tooth band much narrower than premaxillary tooth band at symphysis, tapering laterally. Vomerine tooth band unpaired, continuous across midline; smoothly arched along anterior margin, tapering laterally to point extending posteriorly past level of premaxillary band; band width narrower than premaxillary band at midline, widening laterally and then tapering to sharp point postero-laterally.</p><p>Barbels in four pairs. Nasal barbel slender, extending nearly to tip of supraoccipital process. Maxillary barbel slender, extending slightly beyond tip of humeral process. Inner mandibular-barbel origin close to midline, thicker and longer than nasal barbel and extending to pectoral-spine base. Outer mandibular barbel originates postero-lateral of inner mandibular barbel, extending slightly beyond base of last pectoral-fin ray.</p><p>Body terete, becoming more compressed toward caudal peduncle. Dorsal profile straight or gently convex from tip of snout to origin of dorsal fin, sloping gently ventrally from origin of dorsal fin to end of caudal peduncle. Ventral profile slightly convex to anal-fin base, then sloping slightly dorsally to end of caudal peduncle. Skin smooth. Lateral line complete and mid-lateral in position. Vertebrae 18+21=39 (1), 19+20=39 (5), 20+19=39 (1), 19+21=40 (5), 20+20=40 (8), 19+22=41 (3), 20+21=41 (9) or 20+22=42 (1).</p><p>Dorsal fin with spinelet, spine, and 5,i (3), 6 (8), 6,i (21) or 7 (1) rays. Origin of dorsal fin anterior to mid-body, at about one-third of body length. Dorsal fin margin convex, usually with anterior branch of fin rays longer than other branches. Dorsal fin spine of moderate length, gently curved and slender, posterior edge with 0–9 small, retrorse serrations. Nuchal plate triangular, with straight or slightly convex lateral margins. Pectoral fin with stout spine, sharply pointed at tip, and 6 (1), 6,i (12) or 7 (20) rays. Anterior spine margin smooth; posterior spine margin with 9–15 retrorse serrations along entire length. Pectoral fin margin straight anteriorly, convex posteriorly. Humeral process narrowly triangular, with slightly concave dorsal margin and extending for half to two-thirds of pectoral-spine length. Pelvic fin origin at vertical posterior to posterior end of dorsal-fin base, with i,5 (33) rays and slightly convex margin; tip of adpressed fin not reaching anal fin origin. Anal and urogenital openings located at vertical through posterior third of adpressed pelvic fin. Males with elongate genital papilla reaching to anal-fin base. Adipose fin with convex margin for entire length, with deeply-incised posterior portion and origin separate from base of last dorsal-fin ray; fin-base of moderate length, spanning one-third of postdorsal distance. Anal fin origin at vertical through origin of adipose fin, with v,9,i (6), iv,10,ii (1), v,10,i (11), vi,9,i (7), vi,10,i (3), vii,9,i (2), vi,10,ii (1), vii,10,i (1) or viii,10,i (1) rays and curved posterior margin. Caudal peduncle of moderate depth. Caudal fin deeply forked, with i,7,8,i (33) principal rays; upper and lower lobes slender and pointed. Procurrent rays extend anterior to fin base, with evenly-sloping anterior margins</p><p>Colour. In 70% ethanol: head and body dark brown above, fading to pale yellow on ventral third of head and body. Abdomen pale yellow, lateral margins speckled with brown melanophores. Faint irregularly-shaped yellowish patches on either side of nape, frequently coalescing to form irregular band. Single faint ovoid yellowish patch on sides of body behind tympanic region and below dorsal fin (absent in some individuals). Series of paired faint irregularly-shaped yellowish patches on body: first series above and below lateral line on interdorsal region (between dorsal and adipose fins), second series above and below lateral line below posterior portion of adipose-fin base, third series on dorsal and ventral procurrent caudal-fin rays (absent in some individuals). Yellowish markings on body indistinct in some individuals, with head and body nearly uniformly dark brown (Fig. 7). Dorsal fin with dark brown base and dark brown submarginal bar. Pectoral and pelvic fins with dark brown base and scattered brown melanophores on middle third of fin rays forming diffuse brown band on middle third of fins. Adipose fin dark brown, with narrowly ellipsoid yellowish patch on dorsal surface at anterior origin (absent in some individuals), its posterior margin hyaline. Anal fin hyaline with both a dark brown base and diffuse brown melanophores on proximal three-quarters of fin rays. Caudal fin hyaline with diffuse brown melanophores on fin rays.</p><p>Habitat. Pseudomystus breviceps inhabits forest streams, usually those with a swift current (Ng &amp; Tan, 1999; Ahmad et al., 2024).</p><p>Distribution. Pseudomsytus breviceps is known from the Deli River drainage in northern Sumatra, the Chantaburi River drainage in southeastern Thailand, and river drainages in the Malay Peninsula from the Tapi River drainage southwards to the Endau River drainage (Fig. 5).</p></div>	https://treatment.plazi.org/id/03E5B718FFB6A316C2FEF97BFD82F7C7	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	Ng, Heok Hee	Ng, Heok Hee (2025): Clarifying the identity of Pseudomystus stenomus, with the description of a new species of Pseudomystus from Borneo (Actinopterygii: Bagridae). Raffles Bulletin of Zoology 73: 318-335, DOI: 10.26107/RBZ-2025-0023
03E5B718FFBBA316C140FF1AFA28F7C7.text	03E5B718FFBBA316C140FF1AFA28F7C7.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pseudomystus flavipinnis Ng & Rachmatika 1999	<div><p>Pseudomystus flavipinnis Ng &amp; Rachmatika, 1999</p><p>(Figs. 8, 9)</p><p>Pseudomystus flavipinnis Ng &amp; Rachmatika, 1999: 175, Fig. 5 (type locality: Sungai Embaloh at Benua Martinus, Kalimantan Barat, Borneo); Ng &amp; Lim, 2005: 16; Ferraris, 2007: 103; Kottelat, 2013: 265.</p><p>Leiocassis stenomus (non Valenciennes in Cuvier &amp; Valenciennes, 1840): Vaillant, 1902: 15; Weber &amp; de Beaufort, 1913: 355 (in part); Jayaram, 1968: 364 (in part).</p><p>Pseudomystus cf. stenomus: Kottelat &amp; Widjanarti, 2005: 160.</p><p>Pseudomystus stenomus (non Valenciennes in Cuvier &amp; Valenciennes, 1840): (?) Parenti &amp; Lim, 2005: 190.</p><p>Material examined. MZB 6593, holotype, 47.0 mm SL; Borneo: Kalimantan Barat, Sungai Embaloh at Benua Martinus . – ZRC 61229, 10, 22.9–37.2 mm SL; Borneo: Kalimantan Barat, vicinity of Ketapang . – ZRC 54544, 14, 26.0– 62.5 mm SL; Borneo: Kalimantan Tengah, Kahayan River drainage, Rungan River watershed . – ZRC 65444, 1, 68.5 mm SL; Borneo: Kalimantan Tengah, Kahayan River drainage, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=113.79722&amp;materialsCitation.latitude=-2.0297222" title="Search Plazi for locations around (long 113.79722/lat -2.0297222)">Rungan River watershed</a>, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=113.79722&amp;materialsCitation.latitude=-2.0297222" title="Search Plazi for locations around (long 113.79722/lat -2.0297222)">Tahai area</a>, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=113.79722&amp;materialsCitation.latitude=-2.0297222" title="Search Plazi for locations around (long 113.79722/lat -2.0297222)">Sungai Buyot</a>, feeding to <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=113.79722&amp;materialsCitation.latitude=-2.0297222" title="Search Plazi for locations around (long 113.79722/lat -2.0297222)">Danau Sagumang</a>, 2°1′47″S 113°47′50″E .</p><p>Diagnosis. Pseudomystus flavipinnis is distinguished from all congeners except P. breviceps, P. moeschii, P. myersi, P. nuchalis, P. stenomus, P. tuberosus, and P. vaillantii in having a colour pattern of pale yellow patches on the body (vs. a uniformly brown body, or with either pale yellow transverse bands or longitudinal stripes). It differs from P. breviceps, P. nuchalis, and P. stenomus in having a narrower snout (48–53% HL vs. 54–60; Fig. 3), adipose fin more posteriorly positioned relative to the anal fin (adipose-fin origin posterior to vertical through anal-fin origin vs. at vertical) and the yellow patches on the body frequently (vs. never) coalescing to form irregular bands. Pseudomystus flavipinnis is further distinguished from P. nuchalis in lacking (vs. having) a nuchal concavity (compare Figs. 4 and 8), and from P. stenomus in having a broader nuchal plate with straight or slightly convex margins (vs. narrower nuchal plate with slightly concave lateral margins; Fig. 2). It differs from P. moeschii in lacking (vs. having) a supracleithral process, and from P. myersi in having an adipose fin with a shorter base (14.9–19.5% SL vs. 31.5–34.1) whose posterior insertion is separate from (vs. adnate to) the dorsal procurrent caudal-fin rays. Pseudomystus flavipinnis is distinguished from P. tuberosus in having an evenly sloping (vs. strongly humped) predorsal profile, the absence (vs. presence) of rounded tubercles on the head and flanks, an adipose fin with a shorter base (14.9–19.5% SL vs. 23.3–26.1) and a deeper caudal peduncle (7.8–9.4% SL vs. 5.5–6.0), and from P. vaillantii in having a shorter head (23.5–25.9% SL vs. 27.0–29.0) and adipose-fin base (14.9–19.5% SL vs. 20.3–26.7).</p><p>Description. Morphometric data as in Table 1. Head depressed; dorsal profile evenly sloping or slightly convex. Ventral profile almost straight. Snout broadly rounded when viewed dorsally, width 48–53% HL. Bony elements of dorsal surface of head covered with thin skin. Midline of cranium with fontanelle extending from behind snout to beyond level of posterior orbital margin. Supraoccipital process of</p></div>	https://treatment.plazi.org/id/03E5B718FFBBA316C140FF1AFA28F7C7	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	Ng, Heok Hee	Ng, Heok Hee (2025): Clarifying the identity of Pseudomystus stenomus, with the description of a new species of Pseudomystus from Borneo (Actinopterygii: Bagridae). Raffles Bulletin of Zoology 73: 318-335, DOI: 10.26107/RBZ-2025-0023
03E5B718FFB8A310C1A7FA7CFECFF7C4.text	03E5B718FFB8A310C1A7FA7CFECFF7C4.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Pseudomystus nuchalis Ng 2025	<div><p>Pseudomystus nuchalis, new species</p><p>(Fig. 4)</p><p>Holotype. MZB 17249, 86.2 mm SL; Borneo: Kalimantan Tengah, Barito River drainage, a small tributary of <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.71667&amp;materialsCitation.latitude=-0.3491667" title="Search Plazi for locations around (long 114.71667/lat -0.3491667)">Sungai Laung</a>, 0°20′57″S 114°43′00″E; D. Siebert et al., 16 July 1992.</p><p>Paratypes. BMNH 2001.1.15.2248–2261, 14, 36.3–74.3 mm SL; Borneo: Kalimantan Tengah, Barito River drainage, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.73499&amp;materialsCitation.latitude=-0.3663889" title="Search Plazi for locations around (long 114.73499/lat -0.3663889)">Sungai Laung</a> at <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.73499&amp;materialsCitation.latitude=-0.3663889" title="Search Plazi for locations around (long 114.73499/lat -0.3663889)">Desa Maruwei</a>, 0°21′59″S 114°44′06″E; D. Siebert et al., 15 July 1992 . – BMNH 2001.1.15.2323–2325, 3, 81.8–86.9 mm SL; Borneo: Kalimantan Tengah, Barito River at <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.736664&amp;materialsCitation.latitude=-0.5927777" title="Search Plazi for locations around (long 114.736664/lat -0.5927777)">Muara Laung</a>, 0°35′34″S 114°44′12″E; D. Siebert et al., 20 February 1991 . – BMNH 2001.1.15.2327–2346, 20, 50.7–91.3 mm SL; Borneo: Kalimantan Tengah, Barito River at <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.736664&amp;materialsCitation.latitude=-0.5927777" title="Search Plazi for locations around (long 114.736664/lat -0.5927777)">Muara Laung</a>, 0°35′34″S 114°44′12″E; D. Siebert et al., 8 July 1992 . – BMNH 2001.1.15.2104, 1, 78.8 mm SL; Borneo: Kalimantan Tengah, Barito River drainage, Sungai Pangaren, a small tributary of Sungai Laung, approximately 1 km from Muara Laung; D. Siebert et al., 7 July 1992 . – BMNH 2001.1.15.2347–2352, 6, 70.1–94.0 mm SL; Borneo: Kalimantan Tengah, Barito River drainage, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.73944&amp;materialsCitation.latitude=-0.6155556" title="Search Plazi for locations around (long 114.73944/lat -0.6155556)">Barito River</a> at <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=114.73944&amp;materialsCitation.latitude=-0.6155556" title="Search Plazi for locations around (long 114.73944/lat -0.6155556)">Purukcahu</a>, 0°36′56″S 114°44′22″E; D. Siebert et al., 12 July 1992 . – ZRC 38875, 10, 29.8–65.4 mm SL; Borneo: Kalimantan Tengah, Barito River drainage, market at Purukcahu; M. Kottelat, 22 June 1995 .</p><p>Diagnosis. Pseudomystus nuchalis is distinguished from all congeners except P. breviceps, P. flavipinnis, P. moeschii, P. myersi, P. stenomus, P. tuberosus, and P. vaillanti in having a colour pattern of pale yellow patches on the body (vs. a uniformly-coloured body, or with either pale yellow transverse bands or longitudinal stripes). It differs from P. breviceps, P. flavipinnis, P. moeschii, P. myersi, and P. stenomus in having (vs. lacking a nuchal concavity; compare Figs. 1, 4, 6 and 8), further differing from P. flavipinnis in having a broader snout (55–63% HL vs. 48–53; Fig. 3), adipose fin more anteriorly positioned relative to the anal fin (adipose-fin origin at vertical through anal-fin origin vs. posterior to vertical) and the pale yellow patches on the body never (vs. frequently) coalescing to form irregular bands, from P. moeschii in lacking (vs. having) a supracleithral process, from P. myersi in having an adipose fin with a shorter base (13.2–19.0% SL vs. 31.5–34.1) whose posterior insertion is separate from (vs. adnate to) the dorsal procurrent caudal-fin rays, and from P. stenomus in having a broader nuchal plate with straight or slightly convex margins (vs. narrower nuchal plate with slightly concave lateral margins; Fig. 2). Pseudomystus nuchalis is distinguished from P. vaillantii in having a shorter head (22.1–24.5% SL vs. 27.0–29.0) and adipose-fin base (13.2–19.0% SL vs. 20.3–26.7).</p><p>Description. Morphometric data as in Table 2. Head depressed; dorsal profile with distinct nuchal concavity. Ventral profile almost straight. Snout broadly rounded when viewed dorsally, width 55–63% HL. Bony elements of dorsal surface of head covered with thin skin. Midline of cranium with fontanelle extending from behind snout to level of posterior orbital margin. Supraoccipital process of moderate width, with gently converging sides and emarginate tip; not reaching nuchal plate. Eye ovoid, horizontal axis longest, subcutaneous; located entirely in dorsal half of head. Gill openings wide, extending from post-temporal to beyond isthmus. Gill membranes free from isthmus. First branchial arch with 4+8 (1), 4+9 (1) or 4+10* (1) gill rakers.</p><p>Mouth subterminal. Oral teeth small and villiform, in irregular rows on all tooth-bearing surfaces. Premaxillary tooth band rounded, of equal width throughout. Dentary tooth band much narrower than premaxillary tooth band at symphysis, tapering laterally. Vomerine tooth band unpaired, continuous across midline; smoothly arched along anterior margin, tapering laterally to point extending posteriorly past level of premaxillary band; band width narrower than premaxillary band at midline, widening laterally and then tapering to sharp point postero-laterally.</p><p>Barbels in four pairs. Nasal barbel slender, extending to tip of supraoccipital process. Maxillary barbel slender, extending to slightly beyond tip of humeral process. Inner mandibular-barbel origin close to midline, thicker and longer than nasal barbel and extending slightly beyond pectoral-spine base. Outer mandibular barbel originates postero-lateral of inner mandibular barbel, extending slightly beyond base of last pectoral-fin ray.</p><p>Body terete, becoming more compressed towards caudal peduncle. Dorsal profile straight from tip of snout to about one and a half eye diameter postorbitally, with distinct concavity in profile in nuchal region, sloping gently ventrally from origin of dorsal fin to end of caudal peduncle. Ventral profile slightly convex to anal-fin base, then sloping slightly dorsally to end of caudal peduncle. Skin smooth. Lateral line complete and mid-lateral in position. Vertebrae 19+20=39 (1), 20+19=39 (1), 19+21=40 (1), 19+22=41 (1) or 20+21=41* (3).</p><p>Dorsal fin with spinelet, spine, and 6,i (10) rays. Origin of dorsal fin anterior to mid-body, at about one-third of body length. Dorsal fin margin convex, usually with anterior branch of fin rays longer than other branches. Dorsal fin spine of moderate length, gently curved; posterior edge with 5–10 small, retrorse serrations. Nuchal plate triangular, with straight or slightly convex lateral margins. Pectoral fin with stout spine, sharply pointed at tip, and 6,i (4) or 7* (6) rays. Anterior spine margin smooth; posterior spine margin with 10–16 retrorse serrations along entire length. Pectoral fin margin straight anteriorly, convex posteriorly. Humeral process narrowly triangular, with slightly concave dorsal margin and extending for half to two thirds of pectoral-spine length. Pelvic fin origin at vertical through posterior end of dorsal-fin base, with i,5 (10) rays and slightly convex margin; tip of adpressed fin not reaching anal fin origin. Anal and urogenital openings located at vertical through posterior third of adpressed pelvic fin. Males with elongate, conical genital papilla reaching to anal-fin base. Adipose fin with convex margin for entire length, with deeply-incised posterior portion and origin separate from base of last dorsal-fin ray; fin-base of moderate length, spanning one-third of postdorsal distance. Anal fin origin at vertical through origin of adipose fin, with iv,11 (1), v,9,i (3), v,10 (1), v,10,i (1), vi,9,i* (1) or vi,10 (3) rays and curved posterior margin. Caudal peduncle of moderate depth. Caudal fin deeply forked, with i,7,8,i (10) principal rays; upper and lower lobes slender and pointed. Procurrent rays extend anterior to fin base, with evenly-sloping anterior margins.</p><p>Colour. In 70% ethanol: head and body dark brown above, fading to pale yellow on ventral third of head and body. Abdomen pale yellow, lateral margins speckled with brown melanophores. Faint irregularly-shaped yellowish patches on either side of nape, frequently coalescing to form irregular band. Single faint ovoid yellowish patch on sides of body behind tympanic region and below dorsal fin (absent in some individuals). Series of paired faint irregularly-shaped yellowish patches on body: first series above and below lateral line on interdorsal region (between dorsal and adipose fins), second series above and below lateral line below posterior portion of adipose-fin base, third series on dorsal and ventral procurrent caudal-fin rays (absent in some individuals). Dorsal fin with dark brown base and dark brown submarginal bar. Pectoral and pelvic fins with dark brown base and scattered brown melanophores on middle third of fin rays forming diffuse brown band on middle third of fins. Adipose fin dark brown, with narrowly ellipsoid yellowish patch on dorsal surface at anterior origin (absent in some individuals), its posterior margin hyaline. Anal fin hyaline with both a dark brown base and diffuse brown melanophores on proximal three-quarters of fin rays. Caudal fin hyaline with diffuse brown melanophores on fin rays.</p><p>Distribution. Pseudomystus nuchalis is known from the Barito River drainage in southeastern Borneo (Fig. 5).</p><p>Etymology. The Latin noun ‘nucha’ means ‘the nape of the neck’. The name is used to refer to the nuchal concavity seen in this species.</p></div>	https://treatment.plazi.org/id/03E5B718FFB8A310C1A7FA7CFECFF7C4	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	Ng, Heok Hee	Ng, Heok Hee (2025): Clarifying the identity of Pseudomystus stenomus, with the description of a new species of Pseudomystus from Borneo (Actinopterygii: Bagridae). Raffles Bulletin of Zoology 73: 318-335, DOI: 10.26107/RBZ-2025-0023
