434 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



Islands in 1886 was subsequently found in a Vienna museum and was 

 listed by Mohr (1926b) . The female was unknown until Mohr (1936) 

 described specimens, one male and one female, in the Colonial and 

 Oversea Museum in Bremen, which had been collected in Penang in 

 1906. 



In this fish the length of the upper jaw is equal to its width at base, 

 and the lower jaw in front of the tip of the upper jaw is six times the 

 length of the upper jaw. The dorsal fin, with 12 or 13 rays, has no 

 ray modified. In the anal fin, with 11 or 12 rays, the sixth ray is very 

 broad and elongated, the seventh and eighth rays are slender and 

 elongated, and the remaining rays are unmodified. 



Genus DERMOGENYS van Hasselt 



Dermogcnys van Hasselt, Alg. Konst. Letterbode, vol. 2, p. 131, 1823. (Type, 

 Dermogenys pusillus van Hasselt.) 



DERMOGENYS PUSILLUS van Hasselt 



Dermogenys pusillus van Hasselt, 1823, p. 131 (Java). — Webee and de Beaufoet, 



1922, vol. 4, p. 140 (Siam).— Mohr, 1935, p. 41 (Siam). 

 HemirhampJitis fluviatilis Karoli, 1882, p. 182 (Siam). 

 Dermogenys Smith, 1927d, p. 219 (Siam) ; 1934a, p. 82 (Siam). 

 Demogenys siamensis Fovtleb, 1934a, p. 144, figs. 83, 84 (Chiengmai, Metang). 

 Dermogenys siamensis Fowler, 1937, p. 214, fig. 191 (Bangkok, Paknam) ; 1939, 



p. 41 (Huey Yang). 



This remarkable little fish, whose range includes Java, Borneo, and 

 Sumatra, extending through the Malay Peninsula, is found through- 

 out Thailand in quiet waters — rivers, rivulets, canals, drains, ponds, 

 and lakes. 



The fish is too small to have any food value for human beings, but 

 by its consumption of mosquito larvae it acquires some importance 

 to man. The chief interest in the fish arises from its viviparity and 

 from the extraordinary combativeness of the males. The fish has a 

 more prominent place in Thailand than in any other country to which 

 it is native, because it is there employed in contests of endurance and 

 strength, and because it is cultivated in order to increase its pugnacious 

 qualities. 



From early times the Thai people have had, as a national trait, 

 the strongly developed desire to match various kinds of small animals 

 in contests of strength and skill. Most noteworthy of these animals 

 is the celebrated fighting fish {Betta) . Next in importance is Dermo- 

 genys^ which, though not less interesting from the zoological view- 

 point, has been only slightly noticed in the literature of ichthyology, 

 geography, travel, and sport. 



The effects of cultivation and selective breeding have been mani- 

 fested in a slight increase in the average size of the fish and in a very 

 marked increase in the wrestling or fighting ability. 



