I-REgH-WATER FISHE^ OF SlAM, Ofl THAILAND 423 



anterior margin of fin to posterior rays but not involving the last one 

 or two rays or the bases of the first several rays, the black inclining 

 to blue in some individuals; yellow at anterior base of the dorsal fin 

 extending on back and in males making a conspicuous spot; caudal 

 fin dusky yellow-red, with a narrow blackish edge in males; anal fin 

 white at base, with a bright red zone extending its entire length and 

 one-third of its depth in males, with a pale red border in females; 

 ventrals rich lemon yellow in males, plain white in females ; pectorals 

 hyaline. 



Specimens from a tide pool at Lem Sing, Southeastern Thailand, 

 March 16, 1930, males: Dorsal orange with black spot, caudal rosy 

 orange with a narrow blackish edge, anal bright orange, ventrals yel- 

 low, and pectorals hyaline. Females : Dorsal pale orange with black 

 spot, caudal pale yellow with no dark edge, anal and ventrals white, 

 pectorals hyaline. 



The fish swims at the surface, and its presence in shallow weedy pools 

 or in turbid drains may be disclosed only by tlie glistening silvery 

 white spot on the top of the head at the occiput. It renders a distinct 

 service to mankind by its destruction of mosquito larvae, which appear 

 to be its chief and favorite food. 



It is a great jumper. When put into a shallow vessel it may leap 

 several feet into the air in efforts to escape. This habit is doubtless 

 useful in enabling the fish to evade predatory animals. 



This is one of the various small fishes employed by the Thai in 

 fighting contests. Only the males fight. 



Note on a contest observed at Tachalom, Central Thailand, July 

 28, 1923: A number of males that had been captured 2 days before 

 were brought out, and two that showed signs of a pugnacious dispo- 

 sition were placed in a large circular jar. The fish closed at once and 

 took a characteristic attitude ; head to tail, with sides closely applied 

 and with caudal fins everted at a rather sharp angle. The fish swim- 

 ming at or near the surface forced each other around the jar, and ap- 

 parently sought an opportunity to seize the caudal, anal, or other lower 

 fin and bite out a piece, the jaws being armed with bands of sharp 

 teeth and the upper jaw being protractile. The pair struggled for 10 

 minutes and then stopped from fatigue, without having inflicted any 

 damage to either. The action was much less spirited than in Betta. 

 The glistening white spot on the top of the head became dark in one 

 fish, and this is said to be usual in fighting contests. These fish are 

 matched only by boys who catch the wild fish and hold them in the 

 rectangular jars employed for the regular fighting fish; they will 

 fight after being in captivity 2 days, and their fighting qualities are 

 said to increase with prolonged captivity. 



Notwithstanding its small size this fish is rendered conspicuous by 

 its peculiar shape as well as by the shining spot on the top of the head, 



