SEM studies on first and second gonopod morphology in Mithracidae (Decapoda: Brachyura)

Abstract Gonopods are phylogenetically important morphological characters, and in several cases providing diagnostic characters to support taxonomic phylogenetic studies. Relatively few studies, however, have emphasized in-depth descriptions of gonopods, the functional morphology these structures poorly understood. We use SEM describe illustrate two pairs gonopods (G1 G2) nine species Mithracidae (Majoidea) Macrocoeloma trispinosum Latreille, 1825, recently relocated Epialtidae (Majoidea). The G1 was found present typical characteristics Majoidea: long, with a mesial suture, setae inserted from base distal second third sensilla apical plate; G2 is always short conical. region for analyzed, which could provide differentiating among majoids; also studying functional, reproductive, significance structures.