Feeding habit and growth characteristics of Siganus canaliculatus cultured in sea net cage

Feeding habit and growth characteristics of Siganus canaliculatus cultured in sea net cage were studied during October 2005 to May 2006.The results revealed that S.canaliculatus maily lived in the middle and the lower of the water area and liked to schoole in the cage,was with much vitality,and always to fight with each other for feed.However they were sensitive and easily to be scared by sounds.They were fond of feeding on the algae grown on the net of net cage.The initial average body length and body weight of S.canaliculatus was 83.1 mm and 17.8 g,respectively.After 187 days cultured,the average body length and body weight of the fish was 125.0 mm and 68.4 g,respectively.Every day the body weight averagely increase 0.27 g.The instantaneous growth rate in terms of body weight(IGRW) was 0.72%.The growth of the fish was significantly affected by water temperature.When the average water temperature in sampling period was 23.0 ℃,IGRW was increased to 2.10%.However,when the water temperature was lower than 16.0 ℃,IGRW was decreased to 0.22%.The relationship between total length and body length of S.canaliculatus was linear.The body weight and body length correlation equations was W=0.000 02 L3.055 9(R2=0.930 8).The growth of S.canaliculatus was allometric growth.