Bioecological aspects of Hampala macrolepidota in Lake Singkarak, West Sumatera, Indonesia

Hampala barb, Hampala macrolepidota is a fish species recorded in Lake Singkarak, which has an important economic value, therefore it is harvested by fishermen using fishing rods, gill nets and explosives. Inappropriate methods of harvesting can result in the decrease of fish population, but no recovery action, like artificial breeding, is conducted at the present. Prior to such an initiative, it is necessary to study the biological aspects of H. macrolepidota. This study aimed to determine the range of size, length-weight relationship and growth pattern of H. macrolepidota. This research had been conducted from November 2015 until October 2016 using gill nets and fishing pole as collection methods. The results showed that the distributional frequency of the total length of juveniles ranged from 54 to 166 mm (119.01±24.50), among which males ranged from 175 to 405 mm (284.76±37.54) and females ranged from 167 to 581 mm (380.38±80.93). The body weight of juveniles ranged from 1.2 to 97 g (18.94±10.96), among which males ranged from 50.90 to 821.2 g (264.86±112.87) and females from 41.2 to 2226.7 g (596.40±451.37). The relationship between length (L) and weight (W) for juveniles was W=0.975 L0'581 (r2=0.907), for males was W=0.992 L0'974 (r2=0.836) and for females was W=0.985 L1'053 (r2=0.801). The allometric growth pattern was negative with the model of equation Y=0.975+0.581 X for juveniles, Y=0.993+0.974 X for males and Y=0.984+1.053 X for females, where X=Log W and Y=Log L.