FRESH-WATER FISHES OF SIAM, OR THAILAND 509 



OXYELEOTRIS SIAMENSIS (Gunther) 



Eleotris siamensis Gunther, 1861, vol. 3, p. 129 (Siam) ; 1804, p. 174 (Siam and 



Cambodia).— Bleeker, 1865 (356), p. 174 (Siam). 

 Oxyeleotris siamensis Hoba, 1923b, p. 179 (Bangkok, Nontaburi). — Smith, 1930, 



p. 58 (Siam). 



The fish has its center of distribution in the lower Menam Chao 

 Phya, and in recent years is represented by many specimens from the 

 Bangkok region. It has been reported as far north as Nontaburi, and 

 thence to Paknam. Another stream where the fish has been found to 

 abound is the Tapi River near Bandon, whence numerous living speci- 

 mens were received in Bangkok by the Bureau of Fisheries. 



A maximum length of 17 to 20 cm. is shown by the specimens exam- 

 ined. A female 16 cm. long, from a canal in Tonburi, Bangkok, in 

 June had well-developed ovaries and would have spawned in a few 

 weeks. A fish kept in a glass jar for nearly a month remained motion- 

 less on the bottom without even a fin moving. The habit in a wild 

 state is to lie partly buried in soft mud in shallow water, and it is then 

 easily possible to catch the fish by hand. 



The fish resembles Bostrichthys sinensis (Lacepede) and may easily 

 be mistaken therefor on superficial view. It may be recognized by its 

 dark-brown or smoky-blue general color, dark radiating lines behind 

 the eyes, black ocellus at upper base of the caudal fin, and very small 

 scales, 90 in longitudinal series. 



OXYELEOTRIS MARMORATUS (Bleeker) 



Eleotris marmorata Bleeker, 1852 (55), p. 424 (Bandjermassing, Borneo). — 

 GiJNTHER, 1861, vol. 3, p. 123 (rivers of Siam).— Bleeker, 1865 (347), p. 34 

 (Siam) ; 1865 (356), p. 174 (Siam).— Sauvage, 1883b, p. 151 (Menam Chao 

 Phya). 



Oxyeleotris marmorata Hora, 1923b, p. 179 (Bangkok, Nontaburi). — Fowler, 

 1935a, p. 160 (CallieleotHs platycephalus noted as a synonym) (Bangkok) ; 

 1937, p. 248 (Bangkok). 



Oxyeleotris marmoratus Smith, 1930, p. 58 (Siam). 



Callieleotris platycephalus Fowler, 1934a, p. 156, figs. 123, 124 (Bangkok) . 



The range of this species covers Borneo, Sumatra, Malaya, and 

 Thailand. Locally it occurs throughout the Menam Chao Phya as far 

 north as Paknampo, in Bung Borapet, in the Menam Lopburi, in the 

 Menam Tachin (at Phra Pathom), and in the Peninsula, where there 

 is a record of a specimen taken in the Tale Noi. 



This is not only the largest of the local gobies, but it is also one of 

 the largest in the world. Examples 30 to 40 cm. long are not infre- 

 quently met with, and a maximum length of 50 cm. is reported. 



In the Thai vernacular this fish is called pla hu and pla hu sai (sand 

 goby). 



