Ảnh hưởng của độ mặn lên sinh trưởng, tỷ lệ sống và thời gian biến thái của ấu trùng hàu hương (<i>Spondylus gloriosus</i> Dall, Bartsch & Rehder, 1938)

Abstract

Research effects of salinity on growth, survival rate and metamorphosis of spondylus larvae (Spondylus gloriosus Dall, Bartsch & Rehder, 1938) aims to primarily determine the optimal salinity range for rearing spondy larvae from veliger stage to spat stage, Larvae were reared in 9 containers 85*50*50cm with three salinity levels of 29‰, 32‰ and 35‰ (3 replicates each).

As a result, generally, from veliger stage to umbo stage, growth rate of larvae in lenght from 167,70 to 170,52μm, specific growth rate was 1,55 – 2,34μm/day and it was not significantly different among treatments (P>0,05). Survival rate was from 68,5 – 72,6%, however statistically, the differences are not significant (P>0,05).

As a result, generally, from umbo stage to spat stage, growth rate of larvae from 182,5 to 189μm, specific growth rate was 1,14 – 1,97μm/day and it was not significantly different among treatments (P>0,05). Survival rate was different among treatments. Survival rate was the highest at 32‰ (30,67%), followed by 29‰ (28,67%) and survival rate was the lowest at 35‰ (16,67%) and statistically, the differences were significant between 29 and 32‰ (P<0,05).

Metamorphosis of spondylus larvae from veliger to spat among salinity treatments 29 - 35‰ range 376 – 416 hours (15,67 – 17,33 days), however statistically, the differences are not significant (P>0,05).

Key words: Spondylus, Spondylus gloriosus, salinit, growth, Survival rate, metamorphosis