Currently the Sungei Merbok Project of LKIM is concerned with the seed production of tiger prawns (P. monodon) and seabass (Lates calcarifer), the pond production of tiger prawns and the cage production of seabass and groupers (Epinephelus spp.).
Alternative diets are sought for seabass fingerlings and for grow-out to market size and also for early post-larval (P5-P20) and grow-out tiger prawns. Marine fish are currently weaned as early as possible from live feeds, through Acetes spp., to trash fish. Commercial seabass and grouper cage units are invariably fed trash fish which, though currently relatively cheap, exert a substantial influence on profitability should greater demand and supply shortages cause price increases (Tan et al., 1985). At present, commercial grow-out feeds for prawns are used in the project ponds but these are expensive and not entirely reliable. Particular problems have been experienced in finding a satisfactory early post-larval prawn feed.
An earlier FAO feed consultant (Dr Kai Chow), who visited Sg. Merbok in 1984, left prematurely and there was no follow-up on his recommendations due to lack of supervision. LKIM therefore requested further assistance in this field from UNDP/FAO. A two-month consultancy in feed development was therefore sanctioned for late 1985. This report summarizes the work carried out during that consultancy and gives suggestions for further work on this topic.
Work on live hatchery feeds was not included in the consultant's terms of reference. At briefing and progress review meetings in Kuala Lumpur on 8 and 30 November respectively emphasis was placed upon the developments on finfish feeds. At Sg. Merbok the need for a suitable post-larval prawn feed was also stressed and the author was requested to formulate a feed for the pond grow-out of prawns. Additionally, since there is a possibility that tilapia may be grown in cages in the future, the author was asked to formulate a tilapia feed as well as seabass/grouper diets. Project staff at the site stated that hatchery emphasis in 1986 would be on tiger prawn production. Nevertheless, a suggestion for a fish broodstock diet was also provided by the author.
The arrival of the author coincided with the temporary closure of the hatchery for disinfection, repairs and modifications. The hatchery was therefore without water or air supplies and there were no post-larval prawns available. However, tanks situated outside the hatchery under a shade were made available for experimental use and were provided with water and auxiliary air supplies. These were used for a feed trial with post-larval prawns. Nursery cages (5 × 3 × 3 ft, 1.275 m3) were also made available for a feed trial with fingerling seabass. Only 1 and 3 inch fingerling seabass were available for feed trials; post-larval prawns were obtained from a nearby DOF hatchery.
In view of the above constraints it was decided that the practical on-site work of the author should consist of:
the formulation and demonstration manufacture of feeds for post-larval prawns and fingerling seabass made from locally available materials
two three-week feeding trials with early post-larval prawns and two sizes of fingerling seabass.
In addition, the author would work on the other topics detailed in his terms of reference while at Sg. Merbok. Subsequently, he visited other sites to review feed requirements there, and the final week was spent in Kuala Lumpur. Details of his daily activities are provided in Appendix 20 and a list of persons met in Appendix 21.
