Depth effect on growth of the mussels Perna perna and Perna viridis (Bivalvia: Mytilidae) in suspended culture in the Cariaco Gulf, Sucre state, Venezuela (original) (raw)

The effect of depth (4, 8, and 16 m) on the growth of the mussels Perna perna and Perna viridis was evaluated under culture conditions in the Gulf of Cariaco, Venezuela, during a period of six months. Bimonthly, it was determined the dimension and dry mass of the shell, tissues (somatic and reproductive), and the "fouling" on the shell to both species. At each depth, biweekly registrations of temperature, salinity, dissolved oxygen, and food availability (total, organic seston, and fitoplanktonic biomass) were obtained. At 8 m depth, the highest increments were reached in size, dry mass of the shell, and somatic and reproductive tissues, obtaining P. perna the highest values. The higher growth at this depth was associated with the values of organic seston (>20 mg/L). In both species the mass of the repeat tended to decrease with the increment of the depth, as well as the biomass of the fouling. The lower growth of P. viridis, jointly with the low survival (<30%) in a...