Distribution, abundance, density and morphometry of Strombus gigas (Mesogasteropoda : Strombidae) in Alacranes reef, Yucatan, Mexico

A population of the conch Strombus gigas was sampled in 109 transects (100X 10 m each) for an area of 109 000 m(2) (eight surveys in 1998 and six in 19 99) in Yucatan, Mexico; S. gigas was the most abundant conch species (97% o f individuals) and ocurred at depths of 0.5-18 m. Mean density was 0.0084 i ndividuals/m(2) (Standard deviation SD=0.0138, n=1910). Maximum density (0. 015 individuals/m(2)) was at 0.5-2 m and minimal (0.001 individuos/m(2)) at 16-18 m. Shell length was 120-290 mm (mena=211.6, SD=26, n=1136). Shell li p thick ness, measured only in adults, was 1-28 mm (mean=8.7, SD=7.5, n=113 6).