REPRODUCCIÓN Y CRECIMIENTO DE Spondylus calcifer (CARPENTER, 1857) EN LA ZONA CENTRO OCCIDENTAL DEL GOLFO DE CALIFORNIA (AGUA VERDE, B.C.S.)

Abstract

ABSTRACT Spondylus calcifer (oyster donkey) is the largest species of the family Spondylidae in the mexican Pacific. It is distributed from the Gulf of California to the shores of Peru, inhabiting shallow waters (1-25 m), on rocky bottoms and sandy shoals attached to fragments of rock or coral. In Mexico, is under special protection (NOM-ECOL-059-2001); however there is interest for its exploitation by coastal fishermen. Despite its importance, studies on its biology are limited, so that the objective of this study was to describe the reproductive cycle and estimate individual growth. We collected 449 individuals (January-December 2009) on the west coast of the Gulf of California (Agua Verde, B.C.S). The total sizes ranged from 4.3-16.9 cm shell height (SH). The analysis of the sex ratio indicated significant differences, with males being more abundant than females (1H: 1.58M). Histological analysis of gonads showed that gametogenesis initiated in March and April, with maturity from May-August. Spawning took place from July-October when temperatures were between 27 and 29 º C. Nearly 100% of the organisms were undifferentiated from November-February. The sizes for sex were 9.4-16.3 cm SH for females and 6.1-16.9 cm SH in males, no significant differences in the size structure between sexes. We founded fifteen age groups (0-14), the most representative groups were five, six and four (26%, 18% and 15% respectively). We found a significant correlation between growth and reproduction (Rs=0.70). No significant differences in the growth curve by sex were observed (females: SH∞=18.33 cm, k=0.15 cm year-1 and to=-2.83 years; males: SH∞=18.13 cm, k=0.14 cm year-1 and to=-2.88 years). The size and age of recruitment to reproduction was 12.82 cm SH and 5 years for females and 12.59 cm SH and 5 years for males. S. calcifer is a gonochoric species with the reproductive cycle synchronous, with longevity and growth rate average. Individual growth and reproduction are related with sea surface temperature.