FRESH-WATER FISHES OF SIAM, OR THAILAND 183 



As shown in the foregoing key to the local species of Puntius, this' 

 form may be recognized by the combination of characters comprising 

 denticulated last simple dorsal ray, 4 barbels, about 27 scales in the 

 lateral line, and 14 scales around the narrowest part of the caudal 

 peduncle. 



The general color, varying with age and locality, ranges from golden 

 yellow to silvery green, with a dark brown base to the scales of back 

 and sides ; the dorsal and caudal fins are usually hyaline green ; the anal 

 fin may be milky white anteriorly and bright orange posteriorly; the 

 ventrals and pectorals are orange or yellow. 



The fish seems to be distinguished by the local fishermen from related 

 species and it is called pla tapak at Eaheng and Ban Pong, while on 

 the Nan River it bears the name pla peek. 



PUNTIUS BINOTATUS (Cnvier and Valenciennes) 



Barbus binotatus Cuviee and Valenciennes, 1S42, vol. 16, p. 168 ( Java) . — Fowler, 

 1934a, p. 122, figs. 79, 80 (Chiengmai, Chiengsen, Chiengdao, Bua Yai, Bangkok, 

 Nakon Sritamarat, Chantabun) ; 1935a, p. 121 (Khao Nam Poo, Bangkok) ; 

 1937, p. 198 (Tachin, Mepoon, Pitsanulok, Rayong). 



Barbus (Ptrntius) binotatus Hoea, 1923b, p. 156 (Koh Chang). 



Punthis binotatus Masya and Indeambaeya, 1932, p. 280 (Koh Samui, Koh Pa- 

 ngan).— KouMANS, 1937a, p. 63 (Kapa).— Fowler, 1939, pp. 40, 72 (Huey 

 Yang, Trang). 



Of wide distribution in the Indo-Australian Archipelago and 

 Malaya, this little fish is likewise found abundantly over a large part 

 of Northern, Central, Southeastern, and Peninsular Thailand but it 

 has not been reported from Eastern and Western Thailand. A favor- 

 ite resort is the mountain streams on islands; and the fish may be said 

 to be a characteristic element of tlie fresh-water fauna of Koh Chang, 

 Koh Samui, and Koh Pa-ngan, large islands in the Gulf of Siara. 

 Other mountain streams inhabited by the fish are on Kao Sabap and 

 Kao Bantad, Southeastern area ; on Kao Chong and other mountains 

 in the Peninsula ; and various rivers and brooks in Northern Thailand, 

 including some tributary to the Mekong. In the Central district the 

 fish descends as far as Bangkok. 



A length of 20 cm. or somewhat over is attained. 



The species is subject to considerable variation in markings depend- 

 ent on age. Young specimens always show a round black spot on the 

 back at the base of the anterior dorsal rays and another on the caudal 

 peduncle near the base of the caudal fin; these spots persist with 

 growth and are often the only markings shown, but in large specimens 

 they may be absent. In the young there is an irregular series of small 

 black spots along the longitudinal axis ; these spots later become con- 

 fluent and form a band that in larger examples grows faint and may 



