Hemibagrus wyckii (Bleeker, 1858)

Ng, Heok Hee & Kottelat, Maurice, 2013, Revision Of The Asian Catfish Genus Hemibagrus Bleeker, 1862 (Teleostei: Siluriformes: Bagridae), Raffles Bulletin of Zoology 61 (1), pp. 205-291 : 270-271

Hemibagrus wyckii (Bleeker, 1858)

( Fig. 44 )

Bagrus Wijckii - Bleeker, 1858a: 418 (nomen nudum); 1859g: 135.

Bagrus Wyckii Bleeker, 1858e: 156 (type locality: Java in flumine Tjitarum, provinciae Preanger, prope vicum Parongkalong [Java: Preanger province , Tjitarum [ Citarum ] river, near village of Parongkalong ]).

Hemibagrus Wyckii - Bleeker, 1862: 57, Pl. 72.

Macrones wyckii - Günther, 1864: 83; Bishop, 1973: 350, 354, 357, 358.

Macrones wycki - Weber & de Beaufort, 1913: 343.

Mystus wycki - Smith, 1929: 12; Hora & Gupta, 1941: 28; Suvatti, 1950: 300; Orsi, 1974: 161; Rainboth, 1996: 144.

Mystus wyckii - Fowler, 1935: 104, Fig. 31 ; Smith, 1945: 388; Kuronuma, 1961: 6; Desoutter, 1975: 452, Fig. 4 ; Imaki et al., 1981: 41, Fig. 81; Cramphorn, 1983: 19; Mohsin & Ambak, 1983: 132, Fig. 99; Mai & Nguyen, 1988: 49; Kottelat, 1989: 14; 1994: 413; Roberts, 1989: 126; 1993: 33; Kottelat et al., 1993: 67, Pl. 32; Lim et al., 1993: 6; Roberts & Warren, 1994: 102; Khan et al., 1996: 38.

Macrones Wycki - Durand, 1940: 29.

Mystus (Mystus) wyckii - Jayaram, 1966: 446.

Mystus wickii - Kottelat, 1985: 270.

Hemibagrus wyckii - Mo, 1991: 132; Baird et al., 1999: 92, Fig. 203; Ng & Rainboth, 1999: 563, Fig. 9 ; Gaanantkul et al., 2000: 34; Kottelat, 2001b: 122, Fig. 331; Kottelat & Widjanarti, 2005: 159; Parenti & Lim, 2005: 190; Ferraris, 2007: 91; Vidthayanon, 2008: 116; Ambak et al., 2010: 79; Rainboth et al., 2012: 72, Pl. 46, Fig. 947.

Mystus sp. nov. - Christensen, 1992: 600.

Material examined. — LAOS: NRM 15006, 1 ex., 226.5 mm SL, Mekong River , Pakse ; NRM 15012, 1 ex., 232.2 mm SL ; NRM 15014, 1 ex., 201.9 mm SL, Sedone River , Pakse ; NRM 15021, 1 ex., 269.4 mm SL, Laos .

THAILAND: ANSP 60733 , 1 ex., 143.8 mm SL, Bangkok ; CAS 67222, 1 ex., 176.7 mm SL, Khong Chiam market ; USNM 109578 , 1 ex., 99.8 mm SL, Mae Nam Chem, 80 km above mouth, tributary of Mae Nam Ping ; USNM 109579 , 1 ex., 119.1 mm SL, Mae Nam Ping at Chieng Mai .

CAMBODIA: MNHN 1974–36 , 1 ex., 201.0 mm SL ; MNHN 1974–37 , 1 ex., 290.0 mm SL, Mekong River at Beng Cha ; MNHN 1974–43 , 1 ex., 126.3 mm SL, Kampot ; UMMZ 232311 , 1 ex., 252.0 mm SL ; UMMZ 234581 , 1 ex., 207.1 mm SL, Stung Treng morning market (13°30'N 105°58'E) .

PENINSULAR MALAYSIA: CAS 114175 , 2 ex., 276.5–410 mm SL, Perak: Chenderoh Dam ; ZRC 2446 , 1 ex., 88.1 mm SL ; ZRC 2447 , 1 ex., 73.5 mm SL, Pahang: Kuala Tahan .

SUMATRA: NMW 45279, 1 ex., 160.8 mm SL , Sumatera Barat: Padang ; ZMA 121.811 , 1 ex., 106.0 mm SL , Jambi: Batang Hari ; ZRC 41900, 5 ex., 270.7-564 mm SL , Jambi: Pasar Angso Duo (fish market) .

JAVA: RMNH 6897 , 1 syntype, 330.0 mm SL; BMNH 1863.12 .4.88, 1 syntype, 242.5 mm SL , Jawa Barat, Citarum River ; ZMA 121.860 , 1 ex., 96.5 mm SL , Jawa Barat, Bogor.

BORNEO: Sarawak: USNM 325328 , 1 ex., 288.0 mm SL, Batang Besua where it enters Batang Balui ; USNM 325409 , 1 ex., 226.3 mm SL, Long Paha where it enters Batang Balui .

BORNEO: Kalimantan Barat: CAS 49382, 3 ex. 33.5–204.8 mm SL, Kapuas drainage, rocky channel in main stream of Sungai Pinoh at Nanga Saian ; CAS 49384, 1 ex. 18.6 mm SL, Kapuas drainage, Kapuas main stream, opposite Silat , rocky area on left bank ; CAS 49385, 1 ex., 24.8 mm SL, Kapuas drainage, rocky ledge in middle of Sungai Melawi near confluence with Kapuas main stream ; USNM 230284 , 2 ex., 65.4–149.0 mm SL, Kapuas mainstream 58 km NE of Sintang and 1 km downstream from Sebruang.

BORNEO: Kalimantan Tengah: ZRC 51973, 1 ex., 291.0 mm SL; Kasongan market, from Katingan River , 1°54'S 113°23'E ;

Diagnosis. — Hemibagrus wyckii is distinguished from other members of the species group in having a well ossified dorsal spine at least as thick as the branched dorsal-fin rays (vs. poorly ossified spine thinner than soft dorsal-fin rays) with 10–12 (vs. without) serrations on the posterior edge, a cream-coloured (vs. grey or olive green) cleithral region, cream-coloured (vs. orange, red or grey) procurrent and first principal caudal-fin rays and a shorter maxillary barbel (reaching to the middle of the dorsal-fin base; 144–195% HL vs. reaching to at least the middle of the adipose fin base; 230–301% HL). It can be further distinguished from both H. maydelli and H. wyckioides in having a predominantly grey (vs. reddish or orange-colured) caudal fin, and from H. maydelli in having a greater dorsal to adipose distance (7.1–11.0% SL vs. 4.0–7.0), smaller post-adipose distance (9.3–13.6% SL vs. 14.1–14.6), and a smaller eye (diameter 8–10% HL vs. 12).

Description. — Biometric and meristic data as in Table 29. Head extremely depressed and broad; length 9.7–32.1% SL; width 9.3–23.8% SL. Interorbital distance 29–32% HL. Eye diameter 8–10% HL. Body moderately compressed. Dorsal profile rising evenly but not steeply from tip of snout to origin of dorsal fin, then gently sloping ventrally to end of caudal peduncle. Ventral profile horizontal to origin of anal fin, then sloping dorsally to end of caudal peduncle. Dorsal spine stout, with 10–13 serrations along posterior edge. Adpressed dorsal fin reaching adipose-fin origin. Pectoral spine stout, with 18–21 large serrations along posterior edge. Adipose-fin origin separated from base of last dorsal-fin ray by distance of 7.1–11.0% SL. Post-adipose distance 9.3–13.6% SL. Caudal-peduncle length 14.0–7.4% SL; caudal-peduncle depth 8.1–8.9% SL. Caudal fin forked; upper and lower lobes rounded. Maxillary barbel reaching to middle of dorsal-fin base (144–195% HL). Maximum recorded size 710 mm SL ( Kottelat et al., 1993: Pl. 32; Kottelat & Widjanarti, 2005), but a larger maximum size is expected.

Colour. — Dorsal and lateral surfaces of head and body uniform dark grey, ventral surface of head and body cream grading to light grey towards the lateral surface of body, cleithral region cream; adipose fin grey with cream dorsal margin; anteriormost anal-fin rays, first pelvic-fin rays, and procurrent and first principal caudal-fin rays cream, fin-rays and inter-radial membranes of all other fins dark grey; barbels cream ( Fig. 44b ).

Distribution. — Known from the Mekong and Chao Phraya drainages in central Indochina ( Fig. 45 ). Also known from the Batang Hari and Musi River drainages in Sumatra, the Pahang River drainage in Peninsular Malaysia, the Citarum drainage in Java, and the Baram, Rejang, Kapuas and Barito River drainages in Borneo ( Fig. 45 ).

Habitat and biology. — Hemibagrus wyckii is a large predatory species feeding on crustaceans and fishes ( Rainboth, 1996) found in large rivers (usually in the middle portion of a river drainage). Observations of individuals (about 60–200 mm SL) kept in aquaria indicate that it is a highly territorial species that is aggressive to conspecifics (pers. obs.).

Remarks. — Desoutter (1975) noted the presence of fewer pectoral fin-rays (10–11 vs. 11–12) and more vertebrae (45 vs. 41–44) in Indochinese specimens of H. wyckii when compared to the types (from Java); Ng & Rainboth (1999) concur that this is intraspecific variation and that the Indochinese and Sundaic populations are conspecific.

Figures

Fig. 44. Hemibagrus wyckii: a, UMMZ 234581, 207.1 mm SL, Cambodia: Stung Treng; b, Specimen about 230 mm SL (not preserved); Thailand:Chao Phraya River, Nakhon Sawan Province. (Photograph courtesy of Nonn Panitvong).

Fig. 31. Hemibagrus planiceps, ZRC 44073, 102.9 mm SL; Java: Sungai Cibogo.

Fig. 4. Hemibagrus sabanus, ZRC 40493, 104.9 mm SL, Borneo: Sabah, Segama River.

Fig. 9. Hemibagrus macropterus, ZRC 53403, 117.5 mm SL; China: Suikou.

Fig. 45. Map showing collection localities of Hemibagrus wyckii specimens examined in this study.