Growth of Nodipecten subnodosus (Bivalvia : Pectinidae) in La Paz Bay, Mexico

摘要

Nodipecten (Lyropecten) subnodosus (Sowerby 1835), the largest pectinid in tropical waters, has been continuously exploited. In support of sustainable development for this species, we started basic growth studies to establish aquacultural practices. N. subnodosus was cultured using triangular plastic cages in La Paz Bay (1995-1996) to describe growth and survival; we determined relationships between quantity of available food and growth and behaviour of body component indices. This culture system allows an isometric shell growth of scallops over 13 months; 56.8 +/- 2.1 mm height, 54.5 +/- 2.1 mm length and 23.0 +/- 1.1 mm width. Allometric growth was found between weight and height. length and width (survival was 44.3%). Body component indices and growth increased progressively until the summer of 1996 when all indices decreased negatively, influenced by high water temperatures. Gonad tissue developed during the first year. Gametogenic activity was evident, presenting the first spawn in summer. Particulate organic and inorganic matter and chlorophyll concentrations were relatively constant during the study, and there was no evidence relating these values to growth and body component indices. Culture of N. subnodosus is feasible in La Paz Bay. However, high water temperatures in summer reduced growth and survival rates.