BEBERAPAASPEK BIOlOGllKAN DEMERSAL DAN KRUSTASEA DI PERAIRAN ARAFURA BIOLOGICAL ASPECTS OF DEMERSAL FISH AND CRUSTACEANS IN ARAFURA WATER

Arafura water is one of the centers of demersal fish and shrimp production in Indonesia. The exploitation of demersal fish and shrimp has grown quite rapidly, cause a declining trend in production from year to year. Besides the decline in production, changes also assumed to be occur in community and size structure of demersal fish and crustaceans. This research was conducted in the water of the Arafura in October to November 2006 to know the development of waters resources, particularly demersal fish and crustaceans (shrimp and crab). The result showed that there were changes in the composition of crustaceans, where commercial shrimp production decreased followed by an increase in types of noncommercial crustaceans (shrimp and crab). Family Portunidae (crabs) were very abundant and the most dominant species was Carybdis natator(98% of all crab species caught) with average catch rate of about 66 kg/hr.The size of demersal fish generally showed a declining trend. We observed in this research was much smaller than the previous year. Shrimp catches were dominated by krosok shrimp (Metapenaopsis sp.) which is a non-commercial shrimp