CONICET | Buscador de Institutos y Recursos Humanos

Phenotypic variation of sea urchin Eucidaris tribuloides (Cidaroida: Cidaridae) along theReef Corridor of the Southwest Gulf of Mexico. Introduction: Intraspecific morphological variation can beattributed to the result of genetic variation or influence of environmental heterogeneity. In the latter case, organ-isms are exposed to diverse environmental conditions which have an influence on their biological processes andcan be seen reflected in the morphological adaptations of species. Indeed, Reef Corridor in the Southwest Gulfof Mexico (CASGM, in its Spanish acronym) is constituted of geographically separated reefs that are exposed todifferent large-scale oceanographic factors and show their own attributes with multiple environmental variables.Therefore, this can stimulate morphological variations of species populations that are distributed in this cor-ridor. Objective: The aim of this study was to determine the morphological variation of the Aristotle?s lanternof the sea urchin Eucidaris tribuloides along CASGM. Methods: The allometric relation between height of theAristotle?s lantern and diameter of the test of 104 specimens was analyzed, and we also used a covariance analy-sis to detect allometric differences between groups. Apart from that, the variation of the shape of a rotule and ademi-pyramid for each sea urchin were analyzed using geometric morphometry. Results: There are allometricdifferences among reef systems in the north, center and south of Veracruz. The shape of rotula and demi-pyramidof sea urchins of the north zone are different from the central and south area. However, there were no differ-ences in shape between the center and the South area. The centroid size of rotula and demi-pyramid of the seaurchins of the North are larger than those in the center and the South. Conclusions: Along the Corridor of theSouthwest of the Gulf of Mexico, specimens of E. tribuloides showed a morphological variation in their ana-lyzed structures, these results can be explained by the geographical and environmental gradients of the CASGM,in addition to the feeding habits of E. tribuloides and the availability of the food resource in the habitat wherethey are established. As a stimulus to the morphological variation found in this research, the distance among thereef systems and the marine currents patterns are also considered.