FRESH-WATER FISHES OF SIAM, OR THAILAND 



45 



are of peculiar construction, and their operation takes advantage 

 of the observed habits of the fish. The nets, adapted for drifting, 

 are 120 meters long and 7.5 meters (73 meshes) deep, with a mesh 

 of 5 cm. square. They are set at a depth of 2.5 meters and are kept 

 in an upright position by wooden floats attached to the top rope. 

 At intervals of 6 to 7 meters there is a hollow piece of bamboo, painted 

 white, one end of which is attached by a single cord to the top rope 

 of the net. The nets are set during slack tide, whether flood or ebb. 

 When a fish is caught its struggles are reflected in the movements 

 of the adjacent bamboo markers, which may take a vertical position 

 and are conspicuous in the turbid water. The fishermen in the at- 

 tendant boat draw in the proper section of the net and remove the fish 

 without disturbing the net as a whole. 



Fishing is done daily for about 3 months (November to February), 

 and the average daily catch for all boats at Bangkok is about 100 

 fish. The fish are in good demand on account of their fine flavor and 

 are often sold on the river while the fisher}^ is in progress, so that 

 few may reach the city markets. Fishermen's prices are 1 to 2 bahts 

 per fish. 



As an example of the activity of the fishery, there may be presented 

 the record of a visit made to 15 boats operating along the Bangkok 

 water front during the period between 10 : 30 and 12 o'clock a. m. 

 on February 9, 1926. Six of the boats had no fish, but several of 

 these had already sold their catches to eager customers who came out 

 in boats. The catch of each of the 9 other boats was: 5 females; 

 4 females, 1 male; 3 females, 2 males; 5 females (one 54 cm. long) ; 

 4 females (one ripe *) , 1 male ; 3 females (one 43 cm. ripe, one 53 cm.) ; 

 3 females (one 39 cm. ripe), 2 males (35 and 40 cm.) ; 4 females; 3 

 females (one ripe). 



The following data are for 10 examples of Hiha toll collected from 

 gill-nets on the spawning grounds at Pakret on January 27, 1924 : 



Sex 



Spawning condition 



Length to 



base of 



middle 



caudal 



rays 



Length to 



tip of 



upper 



caudal 



lobe 



Female 

 Female 

 Male.. 

 Male.. 

 Male.. 

 Male.. 

 Male. . 

 Male. . 

 Male.. 

 Male.. 



Ripe 



Unripe, 'ovaries large 



Spent 



Spent 



Spent-. - 



Spent 



Spent 



Spent- 



Spent 



Spent 



49.0 

 35.0 

 32.9 

 32.2 

 31.4 

 31.0 

 29.6 

 25.3 

 23.8 

 22.5 



58.0 

 41.8 

 39.0 

 38.9 

 37.1 

 37.2 

 35.0 

 30.0 

 28.5 

 27.0 



* The term "ripe" means that the eggs were fully mature and that the female had freely 

 running eggs when alive and was ready to spawn. — L. P. S. 



