Aquaculture, 74 (1988) 127-130 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands 127 zyxwvutsr Natural Spawning and Larval Rearing of Milkfish in Captivity in Indonesia A. PRIJONO, TRIDJOKO, I. NYOMAN ADIASMARA GIRL A. POERNOMO, W.E. VANSTONE, C. LIM and T. DAULAY zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONML Research Station for Coastal Aquaculture, Gondol, Bali (Indonesia) (Accepted 13 June 1988) ABSTRACT Prijono, A., Tridjoko, Giri, I.N.A., Poernomo, A., Vanstone, W.E., Lim, C. and Daulay, T., 1988. Natural spawning and larval rearing of milkfish in captivity in Indonesia. Aquaculture, 74: 127- 130. Sixty-seven milkfish broodstock were transported by truck from Jepara, Central Java, to Gon- dol, Northern Bali, over six trips. The duration of transport was 15-17 h. The stocking density in the canvas transport tanks was approximately 15 kg/m3. Conditions of transport were low tem- perature (24-26”C), decreased salinity (20 ppt) and continuous aeration, Natural spawning oc- curred on nine occasions 4 months after stocking, and took place between the end of the major and beginning of the minor milkfish fry season in Indonesia. Weight of spawning fish ranged from 2.1 to 4.9 kg. Larvae, fed a regime of mixed live food, were reared to 21 days of age at a survival rate of 2.2-51.1%. Currently, 400 fish are being reared in four concrete and four canvas tanks on a commercial pelletized feed. The average individual weight of these fish at 2 years of age is 1.5 kg. INTRODUCTION Milkfish is the most extensively cultivated fish in the coastal ponds of In- donesia. Millions of milkfish fry are collected annually from coastal areas for the stocking of ponds. The supply of milkfish from the wild is not sufficient. In 1985, the demand for milkfish fry was 853 million; supply from natural sources was only 801 million. In 1986, the demand for fry was 935 million; the supply was 870 million. Thus, fry availability may be a limiting factor in the development of milkfish culture in Indonesia. Successful induction of ovulation, fertilization of eggs, and larval rearing have been reported by Vanstone et al. (1977)) Liao et al. (1979)) Vanstone and Ricker (1980) and Juario et al. (1984). Hsiao and Tseng (1980) achieved in- duced spawning by using broodstock from rearing ponds. Sexual maturity of the milkfish appears in both natural and artificial environments and is at- 0044-8486/88/$03.50 0 1988 Elsevier Science Publishers B.V.