Callichirus major

Callichirus major sensu lato is a monophyletic species complex of ghost shrimp in the infraorder Axiidea, found in flat sandy beaches across the Pan-American coastline. Originally described as a single species, genetic studies eventually classified it as at least four almost morphologically indistinguishable species, one of which was given the binomial denomination Callichirus macrotelsonis (Peiró, 2012). The complex is distinguished by sexual dimorphism, distinctly separated coxae and bases in the maxilla and gonochorism, despite vestigial signs of ancestral hermaphroditism in C. macrotelsonis. The widespread extraction of individuals for living fishing bait has endangered both its conservation and that of their respective ecosystems.