Effects of Supplementation Substances on Survival Rate of Lutraria Rhynchaena During Seed Transportation

Abstract

This study was conducted to evaluate the effects of Chaetoceros algae and other substances (glucose, active char coal and Oxygen balls) on the survival rate of otter clam Lutraria rhynchaena during transportation and after 20 stocking days. Juvenile clams were packed in nylon bags (2 L of seawater 30‰) with the density of 300 ind./L and preserved during 24 hours at stable temperature of 25oC. Results showed that total ammonium concentration increased abruptly after 24 hours in the treatments without supplements. Adding glucose and Oxygen tablets resulted in higher algal clearance rate of otter clams (70.4 – 75.0%), these levels were significantly higher than those from others (p<0.05). Survival rates of otter clams in active charcoal (83.3%) or Oxygen tablets (83.3%) were significantly higher than in only algae (74.4%) or glucose (71.7%). Although there was not significant difference but after 20 days of rearing otter clams which were preserved with glucose showing the higher results in survival rate (78.9%) and total weight (0.23g). Our findings indicated the ability to supply Chaetoceros algae together either glucose, active charcoal or Oxygen tablets during long transportation to improve the survival rate of otter clams.