EFECTO DE LA EXPOSICIÓN AL OLEAJE EN EL TAMAÑO Y EL ÍNDICE DE CONDICIÓN DE LOS NEOGASTRÓPODOS EN SANTA MARTA, COLOMBIA

The population structure and somatic condition of intertidal gastropods can be affected by the degree of exposure to waves on rocky coasts. We studied the influence of wave exposure and climatic temporality on the sizes and somatic condition of two species of intertidal neogastropods (Plicopurpura patula and Vasula deltoidea), at different sites within the coastal strip of Santa Marta, Colombian Caribbean. The study was conducted in two areas, Santa Marta Bay and Tayrona National Natural Park, where four collection stations were established. The study was carried out from 2015 to 2017 with eight sampling campaigns. Shell size, weight, biofouling proportion, condition index, and wave exposure index were determined. Only in P. patula was there a direct and significant relationship between the level of exposure to waves and sizes (p = 0.011, r² = 0.683). Significant variation in the condition index occurred in V. deltoidea when specimens collected from the upper intertidal exceeded the values of those extracted from the supratidal up to two meters depth. Wave exposure affects the species P. patula, which is found in the supralittoral zones, presenting larger sizes in the sites with greater wave exposure.