The effects of salinity on growth and survival rate of blood cockle (Anadara granosa Linnaeus, 1758) in planktonic larval stage

Abstract

The study aims to assess the effects of varying salinities on the growth and survival rate of planktonic larval blood cockles (Anadara granosa Linnaeus, 1758). Larvae were reared for 17 days from D stage one day old to Pediveliger stage in 100 liter composite tanks with an initial density of 5 individuals/ml and fed algae mixture of Nannochloropsis oculata, Isochrysis galbana and Chaetoceros sp. (with ratio 1:1:1). The experiment was arranged into 5 treatments of salinity: 18‰, 21‰, 24‰, 27‰, 30‰, every treatment was conducted with 3 replications. The results showed that the length, DGR, and survival rate of blood cockle larvae at the treatment of salinity 24‰ were highest, 170.86 ± 3.33 µm, 5.97 ± 0.46 µm/day, and 38.33 ± 0.48% respectively. At the salinity of 27‰, the larval length was 162.16 ± 0.66 µm, the DGR was 5.42 ± 0.65 µm/day, and the survival rate was 37.50 ± 0.55%. Larvae reared at the salinity of 18‰ gave the lowest results, reaching only 131.56 ± 0.23 µm in length, DGR of 3.51 ± 0.64 µm/day, and survival rate of only 21.96 ± 0.62%.