A population of Strombus gigas located at 12 m of depth in Ensenada de Nenguange is studied. The population occupies an area of approximately 98400 m2 The highest average density registered was 1 snail/14 m2 and the lowest was 1 snail/33 m 2 . These density variations seem to be related to environmental conditions, especially water temperature and turbulence. Snails of this population have a massive shell totally covered by algae, corals, sponges and other epifauna; its thick outer lip is constantly eroded by burrowing organisms and continuosly replaced in thickness by the mantle of the snail. Only one size-class of individuals was found, and an almost complete absence of juveniles was observed. Snails were reproductively active in April, May, June an July. Egg masses are described. The importance of protecting rosources like this one, whic in other Caribbean locations are almost extinct by now, is emphasized.