In this study, we have characterized the seasonal reproduction profile and described changes histology of ovary in female rabbit fi sh Siganus guttatus. Besides, we investigated how vitamin E may effect broodfish maturation and ovary performances. Broodfish were fed with supplemental diet of vitamin E at doses of 500, 750 and 1000 mg Vitamin E/kg feed during reproductive season from February to June 2015. | Journal of Fisheries science and Technology - 2016 SEASONAL OVARY DEVELOPMENT AND EFFECTS OF VITAMIN E ON EGG PERFORMANCES IN RABBIT FISH (Siganus guttatus) Pham Quoc Hung1, Phan Van Ut1, Nguyen Van An2, Le Minh Thong3, Ngo Van Luong3 Received: 02/6/2016; Revised: 30/8/2016; Accepted: 26/9/2016 ABSTRACT In this study, we have characterized the seasonal reproduction profile and described changes histology of ovary in female rabbit fish Siganus guttatus. Besides, we investigated how vitamin E may effect broodfish maturation and ovary performances. Broodfish were fed with supplemental diet of vitamin E at doses of 500, 750 and 1000 mg Vitamin E/kg feed during reproductive season from February to June 2015. The results indicated that additional feeding with vitamin E during the conditioning period of broodstock produced no statistically significant effects on gonadal development, fecundities, and egg quality. The absolute fecundities varied from 565,585 to 665,723 egg per female depending upon the size of fish. Generally the bigger the fish, the higher the absolute fecundity. The relative fecundities ranged from 1215 to 1356 egg per g of female. Ripe egg diameter varied between 455 to 480 mm. The GSI at the ovary stage IV varied from to . The study forms a basis for understanding the reproductive biology of a tropical marine finfish with increasing industrial prospects and sustainable aquaculture of this species in Vietnam. Keywords: Rabbit fish, vitamin, Siganus guttatus, reproductive biology, egg quality I. INTRODUCTION Rabbit fish (Siganus guttatus) is a tropical marine finfish species presenting in coastal waters in Vietnam (Le and Le, 2006). Relative to other tropical species such as grouper (Epinephelus spp), cobia (Rachycentron canadum), mangrove red snapper (Lutjanus erythropterus), red drum (Scyaenops ocellatus) and Asian seabass (Lates calcarifer) with a long history of cultivation, the rabbit fish is not yet really commercial cultured because .