Clarias microspilus, Ng & Hadiaty, 2011
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publication ID |
https://doi.org/ 10.11609/JoTT.o2386.1577-84 |
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persistent identifier |
https://treatment.plazi.org/id/03DC8795-FFC2-FFCE-FEAA-FB67FB06FE3D |
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treatment provided by |
Carolina |
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scientific name |
Clarias microspilus |
| status |
sp. nov. |
Clarias microspilus View in CoL sp. nov.
( Image 1 View Image 1 )
Type material
Holotype: MZB 8706, 136.1mm SL; Sumatra: Nangroe Aceh Darussalam Province , Kabupaten Aceh Selatan, Sungai Lembang at Pasilembang (301 ’N & 97021 ’E), coll. S. Wirjoatmodjo et al., 26.ii.1999.
Paratypes: MZB 4768 View Materials (3), 118.7–125.5 mm SL ; ZRC 46418 (1), 127.4mm SL; Sumatra: Nangroe Aceh Darussalam province. Kabupaten Aceh Selatan , Kandang (306 ’N & 97021 ’E), coll. H.B. Munaf, 15.xi.1982 . MZB 8705 View Materials (1), 175.7mm SL; Sumatra: Nangroe Aceh Darussalam Province, Kabupaten Aceh Selatan, Sungai Lembang at Pucuk Lembang (306 ’N & 97028 ’E), coll . R. K. Hadiaty & A. Mun’im, 02.ix.1997 . MZB 8713 View Materials (1), 233.2mm SL; Sumatra: Nangroe Aceh Darussalam Province, Kabupaten Aceh Selatan , swamp at Suaq Belimbing (304 ’N & 97026 ’E), coll. S. Wirjoatmodjo, 21.ii.1999 . ZRC 51917 (4), 127.6–141.6 mm SL; Sumatra: Nangroe Aceh Darussalam Province, Kabupaten Aceh Selatan , Desa Ujung Padang , blackwater swamp along Tapaktuan – Subulussalam road (301 ’55.2”N & 97020 ’17.6”E), coll . T. Sim et al., 18.iv.2009 .
Diagnosis
Clarias microspilus can be distinguished from all Southeast Asian congeners, except for C. intermedius , C. insolitus , C. meladerma , C. olivaceus and C. planiceps , in having a serrated (vs. smooth or rugose, with irregular bumps) anterior margin of the pectoral spine. It differs from C. intermedius and C. meladerma by a longer distance between the tip of the occipital process and the base of the first dorsal-fin ray (6.5–9.2 % SL vs. 2.8–5.6), from C. insolitus , C. olivaceus and C. planiceps by a deeper body (14.9–18.9 % SL vs. 9.7– 15.2) and wider head (18.6–21.7 % SL vs. 14.0–18.7). Clarias microspilus further differs from C. intermedius in having fewer rays in the median fins (64–68 vs. 70– 72 dorsal-fin rays and 51–56 vs. 61–62 anal-fin rays), from C. insolitus in having a shorter distance between the tip of the occipital process and the base of the first dorsal-fin ray (6.5–9.2 % SL vs. 10.3–12.4), and from C. meladerma in having more serrations (22–34 vs. 14–22) on the anterior edge of the pectoral spine. It is further distinguished from C. olivaceus in having a more posteriorly situated frontal fontanel (the anterior tip of the frontal fontanel reaching to a line through the middle of the orbit vs. to anterior orbital margin), a smooth (vs. weakly serrated) posterodorsal margin of the pectoral spine, a shorter distance between the tip of the occipital process and the base of the first dorsal-fin ray (6.5–9.2 % SL vs. 9.3–11.1) and a wider occipital process (31.7–40.8 %HL vs. 25.5–31.5), and from C. planiceps in having a deeper head (12.9–16.0 % SL vs. 9.5–11.5) and smaller interorbital distance (40.5–44.5 % HL vs. 46.4–49.9).
Description
Biometric data in Table 1. Head depressed; dorsal profile slightly convex and ventral profile almost straight. Bony elements of dorsal surface of head covered with thick skin; bones not readily visible, but sutures sometimes evident. Anterior pair of nostrils tubular and medial to maxillary barbel base. Posterior pair of nostrils bordered by nasal barbels anteriorly and fleshy membrane posteriorly; posteromedial to maxillary barbel base. Eye ovoid, horizontal axis longest, subcutaneous; located dorsolaterally on head. Anterior fontanel short and squat (“shoe-shaped” of Teugels, 1986); anterior tip reaching to line through middle of orbits. Occipital process rounded. Gill openings narrow, extending from dorsal-most point of pectoral-fin base to isthmus. Gill membranes free from isthmus but united to each other with 8 (n=5) branchiostegal rays. First branchial arch with 5+13 (n=2) or 5+14* (n=3) gill rakers.
Mouth subterminal, with fleshy, plicate lips. Oral teeth small and in irregular rows on all tooth-bearing surfaces. Premaxillary tooth band rectangular, with median notch on posterior edge. Dentary tooth band much narrower than premaxillary tooth band at symphysis, tapering laterally. Vomerine tooth band unpaired, continuous across midline, crescentic and smoothly arched along anterior and posterior margins. Premaxillary and dentary teeth viliform; vomerine teeth subgranular. Barbels in four pairs; long and slender with thick fleshy bases. Maxillary barbel extending to base of fifth or sixth dorsal-fin ray. Nasal barbel, extending nearly to level of base of last pectoral-fin ray. Inner mandibular-barbel origin close to midline; barbel thicker and longer than nasal barbel and extending beyond base of last pectoral-fin ray. Outer mandibular barbel originating posterolateral to inner mandibular barbel, extending nearly to base of first pelvic-fin ray.
Body cylindrical, becoming compressed towards caudal peduncle. Dorsal profile rising very gently from tip of snout to origin of dorsal fin and thereafter almost horizontal to end of caudal peduncle. Ventral profile slightly convex to middle of head and thereafter almost horizontal to end of caudal peduncle. Skin smooth. Lateral line complete and midlateral in position. Vertebrae 20+40=60* (n=1), 19+42=61 (n=3), or 20+42=62 (n=1).
Dorsal fin with long base, spanning posterior three- quarters of body; with 64* (n=1), 66 (n=3), or 68 (n=1) rays covered by thick layer of skin and without spine. Dorsal-fin margin straight, parallel to dorsal edge of body. Pectoral fin with small spine, sharply pointed at tip, and 8,i (n=5) rays. Almost entire length of anterior spine margin with 22–34 prominent serrations; posterior spine margin smooth or with uneven asperities ( Image 2 View Image 2 ). Pectoral-fin margin straight anteriorly, convex posteriorly. Pelvic-fin origin at anterior third of body, with i,5 (n=5) rays and convex margin; tip of adpressed fin reaching base of first two or three anal-fin rays. Anus and urogenital openings located at vertical through middle of adpressed pelvic fin. Anal fin with long base and 51* (n=1), 54 (n=2), or 56 (n=2) rays covered by thick layer of skin; margin straight and parallel to ventral edge of body. Caudal peduncle very short. Caudal fin rounded, with i,7,7,i (n=5) principal rays.
Coloration
In 70% ethanol: Dorsal and lateral surfaces of head and body violet-gray, fading to pale gray on ventral surfaces. Dorsal, anal and caudal fins violet-gray with very thin hyaline distal margin. Pectoral-fin rays violet-gray, with hyaline interradial membranes. Pelvic fins hyaline. Barbels and pectoral spines violetgray dorsally and light grey ventrally.
Distribution
Known from the short coastal rivers that drain the western face of the Leuser Mountain Range ( Fig. 1 View Figure 1 ).
Etymology
From the Greek, mikros, meaning small, and, spilos, meaning spot. The name is used in reference to the very small white spots arranged in a longitudinal and several transverse series on the body.
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