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Buccinanops globulosus is an edible marine gastropod that is being captured by artisanal fishermen without management regulations. As basic knowledge on population features is required in case a sustained commercial exploitation of this species is established, we estimated and compared the age and growth of B. globulosus in two populations separated by 16 km, inhabiting similar physical environments but different anthropic influence. Our results, based on stable oxygen isotope analysis and best fitted models by likelihood ratio tests, detected differences in age and growth between both samplings. Maximum shell marks suggest one year difference between populations. Richards was chosen as the best fitting model for both sampling sites and significant differences were observed between them. Human activities could be causing the age reduction among other irreversible effects on the population under anthropic influence. This should be considered when developing sustainable management regulations for this fishery resource, especially those based on shell/age size. [ABSTRACT FROM AUTHOR]

The imposex phenomenon is a superimposition of male characters on gastropod females due to exposure to tributyltin (TBT). There have been no previous reports of this phenomenon in the southern Caribbean, which is inhabited by some edible and commercially exploited gastropod populations. To determine whether imposex is affecting some of these local gastropod populations, surveys were conducted at several sites with different levels of boating activity around Margarita Island and on the continental coast of Venezuela. The species affected were Chicoreus brevifrons, Chicoreus (Phylonotus) margaritensis and Leucozonia nasa; however, no females with obstructed vagina were observed. Imposex was observed in a coastal lagoon and on the coast at sites characterized by medium to high boat concentrations, but was not detected in open waters with low marine traffic. A survey of local boat operators indicated that the use of TBT had stopped 2-3 years prior to this study and had been replaced by regular application of other antifouling paints. This is the first report of imposex in Venezuela, but further studies incorporating the bioindicators identified here are needed in order to determine the full extent of TBT contamination and the biological implications in zones with marine traffic. [ABSTRACT FROM AUTHOR]

Gastropods shell shape has been proposed as a good indicator of environmental changes while geometric morphometric (GM) is a powerful tool to detect such changes. Shell shape pattern in adults of the marine gastropod Buccinanops deformis was proved to be correlated with imposex incidence and maritime traffic in populations of Patagonia. We explore through GM the shell shape variation of B. deformis intracapsular embryos in pre-hatching stages of development, in two populations with contrasting maritime traffic and imposex incidence. Embryonic shell shape from polluted and unpolluted areas was significantly different in apex, lateral, aperture and siphonal channel. The same shell shape pattern was observed previously in B. deformis adult specimens. Our results demonstrate that the embryonic shell shape is an early biomarker that could be used as a tool to detect the response to environmental pollution studying abundant egg capsules laid in the field but protecting reproductive adults. [Display omitted] • GM is a useful tool for detecting subtle changes in marine gastropods early development. • In polluted areas, shell shape pattern of intracapsular embryos is similar to adults. • Shell shape in pre-hatching B. deformis embryos is altered by environmental pollution. • Embryonic shell shape is an early biomarker of stress by environmental pollution. The embryonic shell shape varies as a response to environmental pollution during intracapsular development. [ABSTRACT FROM AUTHOR]