Abstract:
Identification and distribution of fish larvae in Rayong Bay from Samae Saen to western coast of Samet Island, were carried out during July, 1986 to April, 1987. Sampling periods were scheduled every month of the total 11 station in the study area. Salinity, temperature and dissolved oxygen were measured in situ. Of the total 27 families of fish larvae recorded from the area, family Gobiidae was the dominant group in terms of abundance and distribution. Fish larvae in the familes of Callionymidae, Carangidae and Engraulidae were next in terms of abundance. Of the latter two families were the economic important fish larvae. Main characteristics of these fish larvae were described and drawn in details. Total density of the Fish larvae (including all families) were highest during the Northeast Monsoon period. During this period, most fish larvae were widely distributed on the Outer Rayong Bay. The lowest density were recorded during the Intermonsoon period (transition period from Northeast to Southwest Monsoon). Of the economic important fish larvae, fish larvae in family Carangidae were most abundant in the Southwest Monsoon period. These fish larvae were widely distributed in the Outer Rayong Bay during the two monsoon periods. The fish larvae in the family Engraulidae, however, were found most concentrated along the Outer Bay during the Northeast Monsoon Environmental factors recorded at each station showed the uniform trend. But these factors varied monthly during the study period. However the fish larvae density did not show significant correlations with the environmental factors recorded. Abundances and distribution of fish eggs were also carried out. The highest density of fish eggs was recorded in the southwest monsoon and the lowest density was recorded in the Intermonsoon period (transition from Northeast to Southwest Monsoon). These fish were also widely distributed in the area of the Rayong River Mouth and the coastal areas of Map Ta Phud during the two Monsoon periods.