Abstract:
Belontia hasselti is belonged to Belontiade family and commonly inhabit in the flood area in the riverside in Riau. However, information on reproductive biology of this fish is rare. To understand the reproductive biological aspects of this fish, a research has been conducted on February-April 2012. There were 123 fishes (102 males and 21 females) captured and TL is ranged from 52 to146 mm and BW ranged from 2 to 68 gr. The sex ratio of male and female is 5:1. In each sampling time there were fishes with 1st, 2nd, 3rd and 4th maturity level. The Gonado Somatic Index (GSI) is arround 0.01-10.46 %. Fecundity is around 142-10,041 eggs. Relationship between fecundity and TL is weak (r=0.03), while the relationship between fecundity with BW and GW are strong, r=0.99 and r=0.99 respectively. The egg size less various, around 0.98-1.00mm in diameter. However, the maturity stages of eggs in the ovary is various. In the 1st maturity level, the eggs are non vitellogenic with 0.05-0.18mm in diameter. In the 2nd maturity stage, the eggs are bigger 0.15-0.44mm and several eggs are in early vitellogenic stage. In the 3rd maturity level, eggs diameter is arround 0.28-1.95mm and there were several vitellogenic eggs. In the 4th maturity level, most of eggg in the ovary are mature (fully vitellogenic), 0.3-0.5mm in diameter. However, in the ovary of the 4th maturity stage fish, there are many immature eggs. This evidence indicates that B. hasselti may be a “partial spawner” and may spawn their eggs throughout the year.
