Taxonomic Review of Pea Crabs in the Genus Pinnixa (Decapoda: Brachyura: Pinnotheridae) Occurring on the California Shelf, with Descriptions of Two New Species

Many species in the genus Pinnixa are not well differentiated, both in life and in the literature. Evolution within the genus has resulted in pairs and groups of very similar species which are frequently difficult to distinguish with existing keys and descriptions. In this paper, the 11 species of Pinnixa previously known from the California shelf are redescribed, with new illustrations. Two species, Pinnixa forficulimanus, new species, and P. minuscula, new species, from soft-bottom shelf habitats, are also described and illustrated, bringing the total number of species present in California coastal waters to 13. Host and distributional data are summarized for each species, and a key for differentiating the species is provided.