FRESH-WATER FISHES OF SIAM, OR THAILAND 



143 



-tJiiiif 





Figure 18. — Cyclocheilichthys heteronema (Bleeker). Drawn by Nal Chote Suvatti; 

 courtesy of the Thailand Government. 



The species may at once be recognized by the multifid maxillary 

 barbels, a feature not possessed by any other member of the genus. 

 The maximum length attained is under 12 cm. 

 The local name for the fish is pla ha ti. 



CYCLOCHEILICHTHYS SIAJA Bleeker 



Cyclocheilichthys siaja Bleeker, 1860 (265a), p. 375 (Borneo; Sumatra). 



This species has heretofore been recorded from Sumatra, Borneo, 

 and Malacca. Its inclusion in this catalog depends on a specimen 24 

 cm. long, taken in the Menam Chao Phya at Bangkok, October 9, 1933, 

 which is thus identified. The specimen has a pair of maxillary barbels 

 whose length is less than half diameter of eye, eye 3.5 in head, 39 scales 

 in lateral line and 11 in transverse series to base of ventral (6 above 

 and 4 below lateral line), 13 predorsal scales, 15 scales around nar- 

 rowest part of caudal peduncle, caudal peduncle longer than deep with 

 its least depth less than 0.5 length of head, a strong fourth dorsal ray 

 whose length exceeds head, pectorals as long as and not reaching 

 ventrals, 1.4 in head, the rays i,18, and a large dark spot on the caudal 

 peduncle. There is thus agreement in essential features with O. siaja 

 as described by Weber and de Beaufort (1916, vol. 3), with several 

 points of difference which may be attributed to individual variation. 

 Incidentally, although Weber and de Beaufort specify that the pectoral 

 fins do not extend to the ventrals, in both of Bleeker's figures of this 

 species (301) (1863, vol. 3) the pectorals are represented as reaching 

 well behind the ventral origin. 



