Hemibagrus guttatus (La Cepède, 1803)

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 : 216-219

Hemibagrus guttatus (La Cepède, 1803)

( Fig. 7 )

Pimelodus guttatus La Cepède, 1803: 96 , Pl. 5 Fig. 1 (type locality: China); Richardson, 1846: 285; Günther, 1864: 99.

Macrones elongatus Günther, 1864: 77 (type locality: Singapore [error]).

Macrones chinensis Steindachner, 1883: 196 (type locality: Canton, China); 1884: 1111, Pl. 8; Pellegrin & Chevey, 1937: 317; Chaux & Fang, 1949: 199.

Aoria chinensis - Rendahl, 1928: 163.

Hypselobagrus chinensis - Herre & Myers, 1931: 248; Herre, 1932: 433.

Aoria guttatus - Herre & Lin, 1936: 23, Fig. 7 .

Leiocassis chinensis - Tchang, 1936: 43, Fig. 3 .

Mystus elongatus - Fowler, 1938: 52; Alfred, 1966: 35; Jayaram, 1978: 225, Fig. 2 ; Jayaram & Sanyal, 2003: 55, Fig. 7 .

Hemibagrus elongatus - Nichols, 1943: 50; Tchang, 1960: 34, Fig. 27 ; Mai, 1985: 284; Mai, 1995: 17, 18.

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

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

Hemibagrus elongatus hongus Mai, 1978: 250 , Fig. 114 (type locality: Song Hong [Red River], Vietnam)

Mystus guttatus - Yue, 1981: 188, Fig. 153; Ni & Wu, 1986: 173, Fig. 97; Cheng & Zheng, 1987: 216, Fig. 1088; Zheng, 1989: 285, Fig. 219; Chu, 1989: 194, Fig. 3 –67; Ze, 1989: 251, Pl. 17; Cui, 1990: 164, Fig. 168; Gao, 1990: 314, Fig. 190; Zheng & Dai, 1999: 72, Fig. 36 ; Zhou et al., 1999: 117; Yang & Zhang, 2006: 414, Fig. II-237, Pl. XII Fig. 111.

Hemibagrus guttatus - Chen, 1984: 412, Fig. 280; Mo, 1991: 132; Kottelat et al., 1998: 566; Ferraris, 2007: 88.

Mystus chinensis - Jayaram & Sanyal, 2003: 53, Fig. 6 .

Hemibagrus hongus - Kottelat, 2001a: 51; Ferraris, 2007: 89.

Hemibagrus dongbacensis Nguy n, 2005: 631, Fig. 48 (type locality: Ky Cung River , Lang Son province, Vietnam).

Material examined. — BMNH 1855.9.19:109, 1 ex., 240.7 mm SL, Singapore [holotype of Macrones elongatus ] .

CHINA: CAS 132536 , 2 ex., 112.1–139.8 mm SL, Zhejiang province : Qiantang River ; CAS 124203 , 1 ex., 151.7 mm SL , CAS 128163 , 1 ex., 271.5 mm SL, Guangdong . CAS 129448 , 3 ex., 164.4–271.1 mm SL ; FMNH 47268 , 1 ex., 238.9 mm SL ; UMMZ 238761 , 1 ex., 108.3 mm SL, Guangdong province : Yingde county, Beijiang River at Beiying ; UMMZ 238988 , 3 ex., 78.6–161.0 mm SL ; ZRC 42555, ex., 328.4 mm SL, Guangdong province : Beijiang River ; ZRC 45661, 11 ex., 180.0– 396 mm SL, Guangdong province : Xijiang River ; USNM 94595 , 1 ex., 251.1 mm SL, Guangxi province : Wuzhou.

VIETNAM: CAS 216759 , 2 ex., 121.0– 125.7 mm SL, Lang Son province: Na Sam market ; ZMUH 256 , 2 ex., 207.6–245.5 mm SL, Na Ri ; AMNH 228041 , 2 ex., 97.8–136.3 mm SL, Nghe An province: Con Cuong district, Chau Khe region, Khe Bu , right branch of river ; MNHN 1937–33 , 1 ex., 224.0 mm SL, Bac Thai province: Song Cau drainage, Bac Can .

Diagnosis. — Hemibagrus guttatus differs from H. macropterus in having a double-chambered (vs. singlechambered) swim bladder, the adipose fin not confluent (vs. partially confluent) with the principal rays of the caudal fin, fewer vertebrae (51–54 vs. 57–59), and a grey or light yellowish body with larger black spots at least one quarter eye diameter (vs. dark brown body with few very small black spots less than one quarter eye diameter). It is distinguished from H. vietnamicus in having a longer pectoral spine (extending beyond a vertical through the base of the dorsal spine vs. to a vertical through the base of the dorsal spine) and fewer vertebrae (51–54 vs. 58–59).

Description. — Biometric and meristic data as in Table 4. General description as for genus. Head depressed and broad, body moderately compressed and elongated. Dorsal profile rising evenly but not steeply from tip of snout to origin of dorsal fin, then sloping gently ventrally from there to end of caudal peduncle. Ventral profile horizontal to origin of anal fin, then sloping dorsally to end of caudal peduncle. Adipose-fin base very long, spanning almost all of postdorsal distance, about 3.0 times length of anal-fin base, not confluent with principal rays of caudal fin. Dorsal spine stout, with 6 serrations on posterior edge. Pectoral spine stout, with 13 large serrations on posterior edge, extending beyond vertical through base of dorsal spine. Anal-fin origin posterior to adipose origin. Adpressed dorsal fin reaching adipose fin. Caudal fin forked; upper and lower lobes rounded posteriorly. Swim bladder with two chambers. Vertebrae 51–54. Maximum recorded size approx. 1000 mm TL.

Colour. — Dorsal surface of head and body uniform light grey to grey (live or freshly-dead specimens with slight yellow hue, fading on preservation); many dark grey spots on side of body one quarter eye diameter or larger, located posterior to origin of dorsal fin, caudal fin with many such spots present; ventral surface of head and body dirty white; adipose fin and fin rays of all fins grey; inter-radial membranes of all fins hyaline.

Distribution. — Hemibagrus guttatus is known from the Hanjiang, Jiulongjiang, and Qiantangjiang drainages in southern China and the Zhujiang (Pearl River, Song Ky Cung) and Song Hong (Red River, Yuanjiang) drainages in southern China and northern Vietnam ( Fig. 8 ). The records from the Hanjiang and Jiulongjiang drainages follow Yang & He (2008). It is also known from Hainan Island, where it has been recorded from the Nandujiang drainage (Ni & Wu, 1986).

fed predominantly on arthropods, with an ontogenetic shift to a diet consisting predominantly of fish and crustaceans at 240 mm SL and larger. This is the largest species in this group: Nichols (1943) reported lengths of up to 1000 mm (most probably TL) and weights of at least 30 lbs. (16.2 kg).

Remarks. — The identity of H. guttatus has been somewhat problematic, and it is only recently (Kottelat et al., 1998) that it has been partially clarified. Hemibagrus guttatus is now a valid species, with H. elongatus ( Günther, 1864) and H. chinensis ( Steindachner, 1883) considered subjective junior synonyms (Kottelat et al., 1998). However, the nomenclatural problems surrounding the exact identity of H. guttatus has been further complicated by Mai (1978), who recognised two subspecies of H. elongatus (considered a junior synonym of H. guttatus ; see Kottelat et al., 1998) from northern Vietnam: H. elongatus elongatus from Na Ri (from the Ky Cung River, which flows into the Xijiang River drainage in southern China) and a new subspecies, H. elongatus hongus from the Song Hong [Red River]. The two subspecies were distinguished by different number of anal-fin rays: H. elongatus elongatus with 12 anal fin-rays and H. elongatus hongus with 12–14 anal-fin rays. The specimens from Na Ri identified as H. elongatus elongatus by Mai (1978) are deposited in ZMUH, Hanoi, but the specimens identified as H. elongatus hongus cannot be found (Mai Dinh Yen, pers. comm. to HHN), and could not be located as well during a visit to the collection in the University of Hanoi in September 1997. We examined the specimens identifed as H. elongatus elongatus by Mai (ZMUH 256), and found that they have 13 anal-fin rays, and not 12 as originally stated. As there are no other significant differences between Mai’s H. elongatus elongatus from Na Ri and H. elongatus hongus from the Song Hong [Red River], the division of the north Vietnamese population into two subspecies is unwarranted.

Hemibagrus guttatus is known from river drainages in southern China and northern Vietnam, but we have not come across any material from Taiwan and Hainan (large islands lying off Habitat and biology. — Hemibagrus guttatus inhabits large rivers, usually favouring areas of rapid current and rocky bottoms. In the northern limit of its range, the species hibernates in deep water during the winter. It spawns in May–June, usually in shallow, sandy areas ( Chen, 1984). The diet of this species in the Zhujiang (Pearl River) has been studied by Hu et al. (2003). Young fish 170 mm SL and under the southeastern coast of China) in our extensive survey of Hemibagrus holdings in most major museums, except for a single case mentioned below. Although a specimen ostensibly collected from Taiwan was encountered (CAS 18294 (1), 370 mm SL), this is most probably mislabelled, as no species of Hemibagrus are known from the streams and rivers of Taiwan ( Oshima, 1919; Chen, 2001). Hemibagrus guttatus is found sympatrically with H. vietnamicus in northern Vietnam, as both species are known from Song Cau (in Bac Thai province) at Cho Moi and Bac Can. However, it cannot be excluded that the northern Vietnamese populations of H. guttatus may have been introduced as Hemibagrus are commonly kept alive and carried around as food fishes in southern China and northern Vietnam (MK, pers. obs.).

Hemibagrus dongbacensis was described from the Ky Cung River, which forms part of the Zhujiang (Pearl River) drainage in northeastern Vietnam. Nguy n (2005) distinguished H. dongbacensis from H. guttatus by differences in the shape of the teeth and tooth patches, shorter maxillary barbels, darker body and smaller size. Using both information in the original description and our examination of material from the Ky Cung River drainage (CAS 216759), we were unable to distinguish H. dongbacensis from H. guttatus , and conclude that the two nominal species are conspecific.

Figures

Fig. 7. Hemibagrus guttatus, ZRC 42555, 328.4 mm SL, China: Beijiang river.

Fig. 1. Method of measurements used in this study: 1, Standard length; 2, Predorsal length; 3, Preanal length; 4, Prepelvic length; 5, Prepectoral length; 6, Dorsal-spine length; 7, Dorsal-fin length; 8, Length of dorsal-fin base; 9, Length of anal-fin base; 10, Pelvic-fin length; 11, Pectoral-fin length; 12, Pectoral-spine length; 13, Caudal-fin length; 14, Length of adipose-fin base; 15, Maximum height of adipose fin; 16, Dorsal to adipose distance; 17, Post-adipose distance; 18, Length of caudal peduncle; 19, Depth of caudal peduncle; 20, Body depth at anus; 21, Head length; 22, Head width; 23, Head depth; 24, Snout length; 25, Interorbital distance; 26, Eye diameter.

Fig.3. Map showing collection localities ofHemibagrus baramensis specimens examined in this study.

Fig.2. Hemibagrus baramensis, ZRC 42742, 150.0 mm SL; Borneo: Sarawak, Mulu.

Fig. 27. Hemibagrus hoevenii, ZRC 39130, 143.3 mm SL; Sumatra: Batang Berbak.

Fig. 36. Hemibagrus lacustrinus, MZB 17183, holotype, 135.3 mm SL, Sumatra: Hulu Batang Ombilin.

Fig. 6. Hemibagrus semotus, ZRC 46121, holotype, 126.0 mm SL, Borneo: Sabah, Padas River.

Fig. 48. Hemibagrus microphthalmus, CMK 14706, 204.6 mm SL, Thailand: Mae Name Moei.

Fig. 8. Map showing collection localities of Hemibagrus guttatus specimens examined in this study.