FRESH-WATER FISHES OF SIAM, OR THAILAND 485 



of streams, and in coastal lakes. The fish has been taken in small num- 

 bers in the Menam Chao Phya in the vicinity of Bangkok and in the 

 ]\Ienam Bangpakong, in the Menam Tapi near Bandon, and in the 

 inner lake of the Tale Sap. It is apparently commoner in the last- 

 mentioned locality than elsewhere in Thailand. Specimens from the 

 Menam Chao Phya are in the British Museum. 



A length in excess of 25 cm. is attained in Thailand. Fish up to 

 at least 30 cm. long are reported from India and the East Indies. A 

 specimen, 25.5 cm. long, from the Tapi Eiver September 29, 1923, was 

 a male with large gonads. 



The appearance of the fish is so different from that of D. microlepis 

 that it is always known by different vernacular names. In Central 

 Thailand it is called pla kapong lai (lai, striped) , in the Tapi Kiver 

 pla kapong sema, and in the Tale Sap pla kapong kin {hin, rock). 

 The large basslike fish Lates calcarifer is pla kapong. 



DATNIOIDES MICROLEPIS Bleeker 



Figure 99 



Datnioides microlepis Bleekek, 1853 (85), p. 442 (Poutianak, Borneo) ; 1859^60 

 (239), p. 101 (Siam) ; 1865 (356), p. 173 (Siam) ; 1876-77 (301), vol. 8, p. 32 

 (Siam). 



This fish, of striking form and color, inhabits Borneo, Sumatra, 

 Cambodia, and Thailand. Locally it has been reported only from the 

 Central section, in the Menam Chao Phya, the Menam Sak, the Menam 

 Nan, and Bung Borapet. 



A length of 40 cm. is attained but the usual size of adult fishes in 

 recent years is under 20 cm. 



The general color varies from clear creamy white or pink to pale 

 yellow, pale yellowish green, and light tan, depending on the water in 

 which it is living, whether weedy swamp, lake, or muddy, turbid, or 

 clear stream. Against this background are sharply defined jet black 

 cross bands. Chevey (1932b, p. 68) points out that in the Indo-Aus- 

 tralian Archipelago this species has seven bands while on the Asiatic 

 mainland there are 6 bands, the third and fourth bands described and 

 figured by Bleeker (Atlas Ichthyologique) as being fused. Thai 

 specimens conform with those from Cambodia, although there is some 

 variation in the position, shape, and obliquity of the bands. Chevey 

 regarded the mainland fish as a distinct geographic race, but was 

 unwilling to give it a varietal name based on the single color character. 



Most of the observations on this fish in Thailand have been made in 

 Bung Borapet. It was the habit of the fish to enter the bung at the 

 period of high water in summer for the purpose of spawning, and to 

 leave during the subsidence of the flood water in autumn. Since the 

 bung has been converted into a vast permanent lake, with the ingress 



590087—45 32 



