Dissolved oxygen depletion on survival and spawning performance of gourami (Trichogaster trichopterus)

Abstract

Dissolved oxygen (DO) depletion commonly occurred in natural environment can cause a series of negative effects in aquatic organsims such as reducing the fish populations, reproduction performances and survival of many fish species. The study of dissolved oxygen depletion on survival and spawning performance of gourami (Trichogaster trichopterus) were conducted for 2 months at the Marine Hatchery Complex of Universiti Malaysia Terengganu. Fifteen pairs of broodstock were exposed to different dissolved oxygen concentration at 1 mg L-1 , 3 mg L- 1 , 5 mg L- 1 , 7 mg L- 1 and 10 mg L- 1 • Hypoxic condition was achieved by introducing the nitrogen gas into the rearing water while high level of dissolved oxygen was achieved by introducing pure oxygen gas into the rearing water. Experimental tank of 1 mg L- 1 , 3 mg L- 1 and 10 mg L- 1 of dissolved oxygen were sealed in order to reduce gas diffusion. There is a significant correlation between dissolved oxygen concentration with survival, spawning performance as well as feed intake in fish. Fish reared in hypoxic condition showed most significant decreased in survival, spawning performance and feed intake while fish exposed in moderate dissolved oxygen concentration especially at 3 mg L- 1 and 5 mg L- 1 shows a significant increased in survival, spawning performance and feed intake.