COMPARISON OF BENTHIC DIATOM EFFICIENCY FOR LARVAL AND JUVENILE ABALONE AQUACULTURE BETWEEN MONO-STRAIN AND WILD MIXED-STRAIN ON WAVY PLATES (PAPAN)

Abstract

The abalone farming industry is increasing to reduce its dependency on wild stocks. This study was conducted to compare some efficiency between mono-strain and wild mixed-strain benthic diatom on wavy plates (so-called “papan”) for larval and juvenile abalone aquaculture. Single species of Navicula incerta and Grammatophora marina were cultured on papans as a mono-strain in laboratory. The papans of mono-strain and wild mixed-strain benthic diatom were kept separately in abalone culture tanks, and larval abalone was inoculated in the tanks. Change of benthic diatom community, settlement rate of larval abalone, and growth rate of juvenile abalone were observed from randomly taken 10 papans of each tank after 2 months of inoculation. The average abundance of benthic diatom on the papans with wild mixed-strain, G. marina and N. incerta mono-strain was 23.2104, 21.6104 and 24.2104 cells/surf. cm2 at the beginning of the study, and 3.3104, 2.8104 and 2.7104 cells/surf. cm2 at the end of the study, respectively. At the beginning G. marina and N. incerta mono-strain occupied 98.9% and 98.7% of total abundance. However, at the end of the study the abundance of G. marina and N. incerta on each papan reduced to 63.3% and 70% among the phytoplankton community. The average number of settled juvenile abalone was 6.4, 10.8 and 10 individual/papan on the papans of wild mixed-strain, G. marina and N. incerta mono-strain, respectively. The settlement rate of larval abalone was 56.2% and 68.7% more on the papans of N. incerta and G. marina mono-strain than that of wild mixed-strain. The average size of juvenile abalone was 2.02, 2.21 and 2.51 mm on the papans of wild mixed-strain, G. marina and N. incerta mono-strain, respectively. The average size of juvenile abalone was 9.4% and 24.2% bigger on the papans of G. marina and N. incerta mono-strain than on that of wild mixed-strain. The average consumption rate of each abalone per day w