Kryptopterus apogon (Bleeker, 1851)

Ng, H. H. Tan H. H., 2000, The cat ® shes (Teleostei: Siluriformes) of central Sumatra, Journal of Natural History 34, pp. 267-303 : 283

Kryptopterus apogon (Bleeker, 1851)

(®gure 7) Silurus apogon Bleeker, 1851b: 67 (type locality: Bandjermassing [= Banjarmasin], Borneo). Cryptopterus apogon: Weber and de Beaufort, 1913: 221 , ®gure 87. Kryptopterus apogon: Kottelat et al., 1993: 68 , pl. 32 (in part).

Material examined. BATANG HARI DRAINAGE: ZRC 38989 (2), 173.2, 206.8 mm SL. ZRC 41903 (1), 477.0 mm SL. ZRC 42561 (1), 90.1 mm SL.

INDRAGIRI DRAINAGE: ZRC 39035 (4), 160.1±205.8 mm SL. ZRC 39097 (1), 344.0 mm.

Remarks. Bleeker (1858b) divided the ®shes placed in Kryptopterus by most subsequent authors into two tribes, Kryptopterini and Phalacronotini, each with two genera. The classi®cation scheme of Bleeker has not been followed by subsequent authors, who have referred all species to the genus Kryptopterus (see GuÈnther, 1864; Haig, 1950). However, recent work by Bornbusch (1995) has shown that the genus Kryptopterus as presently understood is polyphyletic; unfortunately, his study did not conclusively support the division of Kryptopterus according to Bleeker (1858b). As such, we follow Bornbusch (1995) in referring all the species to Kryptopterus .

Kryptopterus apogon may be confused with K. micronema (Bleeker, 1846) , a problem highlighted by Smith (1945), but has not been discussed by subsequent authors. Pending a more detailed study, the identity of this species is tentative and the two species are considered distinct. Kryptoperus apogon can be di erentiated from K. micronema by its longer head (HL 4.6 ±5.3 times in SL vs 5.3±5.7).

Roberts (1989) reported the occurrence of two distinct colour varieties (striped and mottled) in K. macrocephalus , a phenomenon we have also observed in K. apogon (®gure 7). As in K. macrocephalus , no morphological di erences other than colour can be discerned between the two varieties.