Glyptothorax fuscus

Distribution: Chao Phraya, Chanthaburi and Mekong drainages, Thailand, Laos and Cambodia (Fowler, 1934 a; Kottelat, 1989; Rainboth, 1996; Kottelat, 2001 a).

Sumber: Genera of the Asian Catfish Families Sisoridae and Erethistidae (Teleostei: Siluriformes).

Comparisons. Besides G. prashadi (which has already been compared with G. f u s cu s in the diagnosis), there are seven congeners known from the Malay Peninsula and Sumatra: G. amnestus, G. famelicus, G. k e l u k, G. ketambe, G. platypogonides, G. plectilis and G. s c h m i d t i. Glyptothorax fuscus further differs from G. amnestus in having a more tapering body as manifested by the larger ratio between the body and caudal peduncle depths (caudal peduncle depth 2.3 – 2.8 times in body depth at dorsal-fin origin vs. 1.4 – 2.1), from G. famelicus, G. ke t a m b e and G. schmidti in lacking (vs. with) a prominent pale midlateral stripe on the body, and in having a deeper body (depth at anus 15.6 – 20.7 % SL vs. 11.4 – 15.7); it further differs from G. famelicus in having a deeper caudal peduncle (7.4 – 10.9 % SL vs. 5.8 – 7.3). Glyptothorax fuscus is further distinguished from G. keluk in having a deeper body (depth at anus 15.6 – 20.7 % SL vs. 14.0 – 15.8) and a straight (vs. convex) dorsoposterior margin of the adipose fin, from G. platypogonides in having a deeper body (depth at anus 15.6 – 20.7 % SL vs. 12.1 – 14.8), and from G. plectilis in lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus. Among congeners known only from Borneo, it further differs from G. decussatus in lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus, having a more tapering body (caudal peduncle depth 2.3 – 2.8 times in body depth at dorsal-fin origin vs. 2.0), from G. exodon in having the premaxillary toothband not more than three-quarters (vs. almost entirely) exposed when the mouth is closed, a wider head (18.3 – 23.3 % SL vs. 16.0 – 18.1), a shorter dorsal-toadipose distance (14.8 – 20.6 % SL vs. 21.9 – 26.3), a shorter post-adipose distance (15.7 – 20.8 % SL vs. 21.5 – 24.0) and a deeper body (depth at anus 15.6 – 20.7 % SL vs. 13.8 – 15.8), and from G. major in lacking (vs. having) anteromedial striae in the thoracic adhesive apparatus. Glyptothorax fuscus is further distinguished from G. nieuwenhuisi in having a shorter, wider thoracic adhesive apparatus (width 1.3 – 1.6 times in its length vs. 1.6 – 1.9), more tapering body (caudal peduncle depth 2.3 – 2.8 times in body depth at dorsal-fin origin vs. 1.7 – 2.4), and from G. p i c t u s in lacking (vs. having) dark vertical bars at adipose-fin base and base of caudal fin. Among congeners known only from Java, G. f u s c u s further differs from G. platypogon in having a straight (vs. convex) dorsoposterior margin of the adipose fin, a longer caudal fin (28.7 – 33.9 % SL vs. 20.1 – 27.0), and from G. robustus in having (vs. lacking) a medial pit in the thoracic adhesive apparatus, broader skin ridges on the thoracic adhesive apparatus (compare Figs. 3 e and 3 o) and lacking (vs. having) a prominent dark longitudinal stripe running through each caudal-fin lobe. Glyptothorax coracinus is a species that is possibly sympatric with G. f u s c u s for part of its range (southeastern Thailand). Glyptothorax fuscus differs from G. coracinus in having fewer total vertebrae (33 – 35 vs. 36 – 37) and in having a mottled brown or gray (vs. uniform blackish brown) color pattern.

Sumber: The Glyptothorax of Sundaland: a revisionary study (Teleostei: Sisoridae)

Description. Morphometric data in Table 5. Head depressed; body subcylindrical. Dorsal profile rising steeply from tip of snout to origin of dorsal fin, then sloping gently ventrally from origin of dorsal fin to end of caudal peduncle. Ventral profile straight to anal-fin base, then sloping gently dorsally from anal-fin base to end of caudal peduncle. Anus and urogenital openings located at vertical through middle of adpressed pelvic fin. Skin tuberculate, with tubercles of on sides of body generally larger than those on dorsal surfaces of head and body. Lateral line complete and midlateral. Vertebrae 16 + 17 = 33 (4), 17 + 16 = 33 (2), 16 + 18 = 34 (6), 17 + 17 = 34 (17), 18 + 16 = 34 (2), 17 + 18 = 35 (8) or 18 + 17 = 35 (3). Head depressed and broad, triangular when viewed laterally. Snout prominent. Anterior and posterior nares large and separated only by base of nasal barbel. Gill openings broad, extending from ventral margin of posttemporal to isthmus. First branchial arch with 2 + 6 (7), 2 + 7 (12) or 3 + 8 (1) rakers. Bony elements of dorsal surface of head covered with thick, tuberculate skin. Eye ovoid, horizontal axis longest; located entirely in dorsal half of head. Barbels in four pairs. Maxillary barbel long and slender, extending to middle of pectoral-fin base. Nasal barbel slender, extending to midway between its base and anterior orbital margin. Inner mandibular-barbel extending to midway between its base and that of pectoral spine. Outer mandibular barbel extending to two-thirds of distance between its base and that of pectoral spine. Mouth inferior, premaxillary tooth band partially exposed when mouth is closed. Oral teeth small and villiform, in irregular rows on all tooth-bearing surfaces. Premaxillary teeth appearing in single broad semilunate band. Dentary teeth in a single crescentic band, consisting of two separate halves tightly bound at midline. Thoracic adhesive apparatus consisting of keratinized striae in an ovate field extending from isthmus to just beyond posterior limit of pectoral-fin base (Fig. 3 e). Narrow, chevron-shaped medial pit on posterior third. Striae around posterior half of median depression anastomosing. Dorsal fin located above anterior third of body, with I, 6 (20) rays; fin margin straight; spine short and straight, smooth on anterior and posterior margins. Adipose fin with anterior margin straight or slightly concave and posterior margin straight. Caudal fin strongly forked, with slightly rounded tips, lower lobe slightly longer than upper lobe and i, 7,8, i (20) principal rays. Procurrent rays symmetrical and extending only slightly anterior to fin base. Anal-fin base vertically opposite adipose-fin base. Anal fin with straight anterior margin and straight or slightly concave posterior margin; with iv, 8 (1), iv, 8, i (3), iv, 9 (4), v, 8, i (2), iv, 9, i (4), iv, 10 (2), v, 9 (1), iv, 10,1 (1), iv, 11 (1) or v, 9, i (1) rays. Pelvic-fin origin at vertical through posterior limit of dorsal-fin base. Pelvic fin with slightly convex margin and i, 5 (20) rays; tip of adpressed fin not reaching anal-fin origin. Pectoral fin with I, 7 (1), I, 7, i (16), I, 8 (1) or I, 8, i (2) rays; posterior fin margin slightly concave; anterior spine margin smooth, posterior margin with 3 – 10 serrations. Coloration. In 70 % ethanol: dorsal and lateral surfaces of head and body reddish brown to dark gray, fading to paler color (beige to light gray) on ventral surfaces. Dorsal and lateral surfaces of head and body with small irregular darker spots in some individuals, particularly towards posterior half of fish (Fig. 16). A thin, pale (usually cream) mid-dorsal stripe extending from base of last dorsal-fin ray to origin of adipose fin; stripe indistinct or nearly absent in some individuals. Laterosensory pores rimmed in beige, imparting appearance of a diffuse light brown midlateral line in some individuals. Dorsal and ventral surfaces of caudal peduncle slightly paler in some individuals. All fins with rays proximally brown or gray, becoming hyaline more distally, and diffuse melanophores on fin membranes. Pectoral and pelvic fins with brown or gray on base of fin rays and hyaline posterior margin. Anal fin with brown base; brown spot on anterior third of fin present in some individuals. Adipose fin brown with hyaline distal margin. Base of caudal fin with dark crescent in most individuals. Each caudal-fin lobe with irregular, elongate brown or gray blotch on about half of outer fin rays; most of inner rays of lobes hyaline. Maxillary and nasal barbels brown to gray dorsally, beige ventrally. Mandibular barbels beige.

Sumber: The Glyptothorax of Sundaland: a revisionary study (Teleostei: Sisoridae)

Glyptothorax cf. major — Kottelat et al., 1992: 10; Kano et al., 2013: 179. Glyptothorax sp. cf. major — Miyazaki et al., 2013: 1041, Fig. 3 E.

Sumber: The Glyptothorax of Sundaland: a revisionary study (Teleostei: Sisoridae)

Glyptothorax laosensis (non Fowler, 1934) — Fowler, 1939: 57.

Sumber: The Glyptothorax of Sundaland: a revisionary study (Teleostei: Sisoridae)

SINGAPORE: CAS-SU 32674 (1), 38.9 mm SL; Mandai Road. BANGKA: ZRC 30736 – 30742 (7), 34.6 – 45.0 mm SL; CMK 9619 (9), 28.5 – 45.6 mm SL; stream 9 km E of Mentok. ZRC 31263 – 31264 (2), 24.6 – 48.7 mm SL; CMK 9646 (1), 44.9 mm SL; 28 km N of Payung. SUMATRA: UF 166633 (1), 29.3 mm SL; Sumatera Selatan: Air Rambang, 3 ° 33 ' 2 " S 104 ° 15 ' 50 " E. UF 166632 (1), 34.6 mm SL; Sumatera Selatan: Air Kikim Kecil, 3 ° 45 ' 50 " S 103 ° 27 ' 34 " E. ZRC 53528 (1), 43.3 mm SL; Sumatera Selatan: market in Lahat, Lematang (Musi) drainage, 3 ° 48 ' S 103 ° 32 ' E. UF 166631 (1), 46.0 mm SL; Sumatera Selatan: Air Enai, 4 ° 3 ' 39 " S 104 ° 2 ' 52 " E. UF 167899 (31), 23.9 – 58.6 mm SL; Lampung: Way Besai, 4 ° 45 ' 27 " S 104 ° 33 ' 20 " E. UF 166638 (1), 46.8 mm SL; Lampung: Way Sebetih, 4 ° 37 ' 36 " S 104 ° 59 ' 53 " E. UF 161617 (2), 51.2 – 60.3 mm SL; Lampung: Way Seputih draiange, 5 ° 4 ' 189 " S 104 ° 53 ' 3 " E.

Sumber: The Glyptothorax of Sundaland: a revisionary study (Teleostei: Sisoridae)