Impacts of Nursing Density on Growth, Survival and Metamorphosis Development of Mantis Shrimp Larvae (Harpiosquilla harpax) in Vietnam

The current study was conducted to evaluate effect of larvae density on the growth, survival and development of larvae metamorphosis under nursing conditions. Triplicates of three densities S50, S70 and S90 (50, 70 and 90 larvaes.L-1 respectively) were set up in an 80 litter plastic tank system. Larvae were fed on live algae, artemia and artificial feed. All the water parameters were maintained at optimum levels (>5 mg O2 .L-1, pH from 7.5 to 8.5 and salinity from 28-30%). Larvae development was monitored every hour until they finished metamorphosis. Length and survival rate were measured. The results showed that nursing density could impact to growth and survival rate of larvae. Growth of larvae in S50 group was highest and reached 8.34 mm, followed by S70 (8.00 mm) and S90 (7.84 mm). Similarly, S50 showed the highest survival rate (11.05%), higher than that of S70 (6.54%) and S90 (4.36%). The lower density also finished metamorphosis stage earlier (1,007 hours) as compared to S70 and S90 (1,014 and 1,024 hours respectively). However, these differences were not significant. The results showed the possibility of reproduction mantis shrimp larvae on practical farms.