Abstract:
Anabas testudineus is a type fish that commonly inhabit blackwater area such as swamp, stream and
canals in Riau. Eventhough this fish can be found easily, information on its biological aspect is rare. To
understand the reproductive biology of this fish, a study has been conducted. The A. testudineus was
sampled in irrigation canals in the palm tree plantation area in the Bencah Kelubi Village, Kampar
Regency, Riau, from January to March 2013. There were 153 fishes ( 68 males and 85 females)
captured. The size offish is various, female ranged from 61 -145 mm TL and 11 -126 gr BW, and
that of the male was 49- 131 mm n. and 4-79 gr BW. In January, almost all of fish were in the 111 to
2"d maturity stages and there was no mature fish. In February and March, however, there were mature
males and females captured. It is predicted that mature male released pheromone that attract females
and causing sex ratio between male and female was around 1 : 2.4 in the last 2 months. The male can
be distinguished by longer dorsal fin, slimmer and darker body color. Study on histological structure of
gonads shown that the ovary of mature female is dominated by mature eggs, indicated that this fish is a
total spawner. In the testes tissue, surprisingly, there is trace of egg remains, indicated in special
condition this fish might be able to reverse their sex
