Abstract

The queen conch Strombus gigas is a large herbivorous gastropod which represents one of the most important fishery resources of the Caribbean. High fishing pressure and destruction of its natural habitat have caused severe depletion of stocks throughout the region and many of the populations haven’t recovered despite of management and rehabilitation efforts. The conch’s life cycle is highly complex, implying various ontogenic habitat shifts and migrations. The distribution of juveniles generally is restricted to certain areas and the majority of the previous studies are either biased towards aspects of juvenile ecology or adult ecology, but few studies have addressed connectivity between nurseries and reproductive aggregations. The inlet of Xel-Há is a natural protected area under private administration, hosting a population of S. gigas. In the present study we assessed size distribution and mobility throughout the inlet using a stratified mark-recapture scheme at four sites (Cueva, Centro, Bocana and Brazo N) in order to determine how S. gigas uses its habitat and how the different stages of its life cycle connect in it. A total of 8,292 conch was tagged between 2005 and 2011. The population was composed of 70% juveniles. At Cueva, Centro and Brazo N mainly juveniles were captured, while at Bocana mostly adults were encountered. Mobility increased in adult and sub-adult conch and during summer months. Spatial distribution and mobility could be associated to length and lip thickness, suggesting that conch might undergo ontogenetic niche shift as they reach sexual maturity.

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