The seabass, barramundi bream or giant sea perch (Lates calcarifer) belongs to the Centropomidae, a small family of percoid fishes distributed between Africa and the Pacific.
L. calcarifer is the main centropomid species in Asia and Oceania and nominal catches of this species at 20 968 t (FAO, 1987) 1 comprise 10% of the total nominal world catch of the family.
Another common species, the Nile perch (Lates niloticus) is found in the Nile river system and elsewhere in Africa where it is also commercially important; 168 000 t being landed in 1986 (FAO, 1987).
The seabass is a diadromous fish growing to considerable size in freshwaters before proceeding to the sea for breeding. It is widespread in Asia and Oceania reaching latitudes as far as 25°N and 35°S.
The seasonal availability of juveniles in the coastal waters and tambak systems of many parts of Asia has stimulated development of aquaculture to augment the catches of wild seabass or (in Australia) to increase wild stocks for recreational fishing. Subsequently the hatchery propagation of seabass has enabled a regularization of farming systems which range from earthen freshwater ponds to brackish lagoons and marine cages.
The groupers belong to the large family of percoid fishes, the Serranidae, found throughout the warmer seas of the world and highly valued as food fishes particularly in Southeast and East Asia and the Caribbean. The term grouper is usually used for species of the genus Epinephelus but often expanded to cover other serranid genera such as Plectropomus and Variola (coral trouts), Cephalopholis (coral cods), and Cromileptes (high-finned grouper), amongst others.
Groupers may grow to a large size, of several hundred kilogrammes, but in Southeast Asia are commonly marketed at 0.25–10 kg each. Groupers may be found both in coral reef areas and on sandy or muddy bottoms and several species in estuarine environments are moderately euryhaline.
They are caught in a range of demersally oriented capture fisheries throughout the warm waters of the world; in East Asia either by non-specific trawl fisheries or by specific methods such as lining or trapping for premium and usually live fish, and yielding at least 38 000 t in 1987 (FAO, 1987); Indonesian catches totalled 15 364 t in that year.
Groupers are particularly appreciated by ethnic Chinese consumers - in Hong Kong groupers fetch higher prices as fresh fish than any other group of top-grade fish, and a price of three times or more is paid for live specimens.
The high value placed on groupers by a wide range of consumers has made them a prime target for aquaculture in several countries, notably Hong Kong, Singapore, Thailand, Malaysia, China and Taiwan. Despite their value there has not been notable success in artificial propagation of groupers, and the bulk of fingerlings required for on-growing continues to be obtained from the wild. Marine cage culture is the most common form of aquaculture for groupers, though in certain areas, e.g., Taiwan, brackish ponds previously used for black tiger shrimp production are more commonly used.
Snappers are another large family of percoid fishes, the Lutjanidae, distributed throughout tropical and sub-tropical regions. Twenty or so species are found in the Indo-Pacific region where they are an important component of the larger fishes taken by generally demersal fishing gear (Allen, 1985).
Snappers are appreciated as a food fish by a wide range of people, and red species of Lutjanus commonly enter international trade as red snapper both regionally and worldwide. They occupy a similar range of habitats as groupers. Like the groupers, the coral reef forms tend to be brightly patterned and the muddy bottom forms basically unpatterned. Regional catches of lutjanids totalled 66 000 t, and marine catches of red snapper in Indonesia comprised 31 758 t of that total.
Despite widespread production from the capture fisheries of the region, snappers have attracted some attention as candidates for aquaculture in a few countries where they have been artificially propagated, e.g., Singapore.
Two other families contain species suitable for consideration as seafarming targets, the Carangidae and Siganidae.
Carangids are a very numerous family of mainly schooling pelagics common throughout the world and including the horse mackerels, scads, jacks, crevalles, kingfishes, etc. In bulk the scads and horse mackerels probably dominate as cheap food fish, often used for canning or meal production together with the cheaper clupeoid and scombroid fishes. Smaller crevalles are commonly taken by small-scale demersal as well as pelagic fisheries throughout the region and fetch moderate prices. In 1987 Indonesian catches included 14 257 t of Caranx spp. and 72 977 t of the smaller carangids, Selar spp.
The larger kingfishes are less abundant in catches but command good prices in a few countries; in Japan an extensive aquaculture has been developed for a particular kingfish species, Seriola quinqueradiata, the yellowtail, which yielded 150 000 t in 1987.
Several species of crevalles, which can easily be taken alive in various capture fisheries particularly by lift net or seine, have been adopted as secondary targets for marine seafarming. They feed easily on trash fish and grow quickly in enclosures.
The Siganidae or rabbitfishes are a unique family as regards marine aquaculture since they are herbivorous (or more correctly omnivorous) rather than carnivorous. Siganids are a small group of generally small fishes, seldom exceeding 750 g and popular in parts of the region; their catches are not disassociated in Indonesian statistics.
Some siganids are a pest in seaweed farming areas but their herbivorous nature can be advantageous in cage culture: a few specimens per cage can help to reduce the fouling of net meshes.
