Survival and growth of mangrove oyster Crassostrea gasar (Dautzenberg, 1891) reared at different depths in ponds in Benin (West Africa)

The objective of this work was to study the survival and growth juveniles oyster Crassostrea gasar reared in ponds at different depths. Rearing trials were carried out for 42 days (6 weeks) two (12 m2 x 1.10 m deep), one which fertilized with poultry droppings other no fertilization. For each pond, 03 depths (30 cm, 60 cm 90 cm) tested duplicate. At depth, iron mesh bags (40 20 10 used. Oysters an average size 40.50 mm weight 15.36 g cultivated a density 30 individuals per bag. Phytoplankton density, pH, temperature, transparency salinity water daily measured between 7:00 8:00 am. counted weekly. Individual length evaluate their growth. values physico-chemical parameters during met requirements tropical oysters. After 6 weeks rearing, best rates observed (86.67% 81.67% unfertilized ponds, respectively) while lowest (46.67% 41.67 recorded depth. highest mean final sizes (40.584 40.568 depth (40.557 40.553 same order) ranged from1 5.32 (at depth) 15.38 it overlapped 15.3 (90 15.35 pond. gain 0.0004 g/day 0.0005 respectively zootechnical performance Fertilized pond culture highlight future prospects promotion controlled environment.