Effect of Different Substrata on the Growth and Survival of Green Mussel Perna viridis in Raft Culture at Ratnagiri (India)

The rens fromtwo substrata viz., nylon rope (2.5 mlength and 24 mm diameter) and nylon strip (1.5 m length and 5 cm width) were prepared and suspended from wooden raft (6.32 x 2.7 m), anchored at depths 3.5-4.0 m in the Kalbadevi estuary (10°59’1’’N and 73°10’25’’E) at Ratnagiri. The seeds of Perna viridis with an average initial shell length of 31.1 ± 0.08 and 31.2 ± 0.07 mm were seeded in nylon rope and nylon strip rens, respectively. In this experiment, 10 replicates were used for each ren. The green mussel attained the shell length of 67.3± 0.7 and 65.5 ± 0.62 mm in 7 months for nylon rope and nylon strip rens, respectively. The average survival of 54.09% with an average production of 11.32 kg.m^-1 was obtained in nylon rope, whereas average survival of 35.26% with average production of 9.12 kg.m^-1 was obtained for nylon strip rens in 7 months. The growth of mussels on nylon rope and nylon strip ren was not significant, but survival and production of mussels were significantly higher in nylon rope compared with nylon strip ren during raft culture.