EFFECT OF SPANISH AND FRENCH NETTING METHODS ON GROWTH AND LOSSES OF SUSPENDED CULTURED MUSSELS (MYTIL US PLA TENSIS D ’ORB.).

Abstract

Growth and losses of mussels (Mytilus platensis d’Orb.) in hanging cultivation with spanish and french netting methods are compared. The seed was obtained from artificial net collectors and the experimental ropes were suspended ¡n the Golfo Nuevo (Chubut, Argentina: 64° 59" W y 42° 46' S), on a subsuperficial long-line system for a fifteen month period (March 1988 - June 1989). Data were studied using analysis of covariance and contingence tables (G-test). The average length was significantly higher using the spanish method than in the french method. Losses were significantly higher at the beginnig of the experience in the spanish method, in the 12th month there was no difference, and were significantly higher in the french method at the end of the
experience. The meat weth weight by rope meter increases with both methods until the 12th month of cultivation and decreases in the 15th month; this weight is always higher in the spanish method. The harvestable biomass (by meter of initial rope) is a function ofthinning out operations and it was maximal in the 12th month in ropes of the french method.