Production of marketable‐size tilapia,Oreochromis spilurus(Günther), in seawater cages using different production schedules*

摘要

Abstract.In Kuwait, the culture of tilapia,Oreochromis spilurus(Günther), in sea cages is limited by water temperature for mid‐April to mid‐November only. Using fry spawned in April, one production cycle is passible, but marketing time is limited to less than 20 days. With a market capacity of 1 tonne/day, the production of 100 tonnes/year planned for a commercial farm requires 100 marketing days. It is therefore necessary to shorten production time by stocking larger fingerlings to extend the marketing period.Four fingerling production schedules were tested, using fry spawned (1) in May, grown normally; (2) in May, stunted; (3) in August; and (4) in December. The fish were initially stocked and overwintered in fibreglass tanks. On 19 April, the fish were transferred to 1‐m3net cages at 150 fish/cage and grown to marketable size (<300g).Results showed that fish spawned in May (normal and stunted), August and December were harvested in July, August and October and can be marketed for 125, 100 and 60 days, respectively. It is apparent that the production of 100 tonnes of tilapia to be marketed over a period of 100 days is possible using fry produced in August; the profit, however, is marginal. Fry spawned in December gave the highest