Morfología de gonópodos entre siete especies de cangrejos eubraquiuros (Crustacea: Decapoda)

The first and second gonopods (G1 and G2, respectively) in Eubrachyura crabs are covered with cuticular specializations that vary in shape and size. Describing these specializations would allow a better understanding of this organ and its role in copulation, especially if associated with the internal structure of the gonopods. Therefore, this study aims to contrast the morphology of the gonopods of seven species of Eubrachyura. The specimens were analyzed macroscopically, histologically, and microscopically using SEM. The G1 and the G2 in all species are formed by two segments, with G1 presenting an ejaculatory canal that is lacking in G2. Apical projections were observed in four species. The G2 endopodvaries in size among species. Five types of setae were observed: simple, pappose, papposerrate, conical, and paddle-shaped. Histologically, G1 and G2 are very similar, differing in that G1 presents the ejaculatory canal in longitudinal and transverse sections, as well as tegumentary glands, whereas G2 lacks both. There is a trend in the morphology of Eubrachyura crab’s gonopods which corresponds to the groups Thoracotremata and Heterotremata. The observed morphological variations suggest the presence of species-specific gonopod types.