Crabs of the family Homolodromiidae, VI. Homolodromia monstrosa new species (Decapoda: Brachyura) from the Western North Atlantic with a redescription of the holotype of Homolodromia paradoxa A. Milne Edwards, 1880 and comments on sexual dimorphism

Description

Abstract

A new species of the crab genus Homolodromia A. Milne Edwards, H. monstrosa, is described from four specimens collected in the western Atlantic. The collection consists of two females that differ markedly from descriptions of H. paradoxa (the only other member of the genus known from the western Atlantic) and two males that differ only slightly from H. paradoxa. The holotype of Homolodromia paradoxa A. Milne Edwards, a damaged male from the Leeward Islands, Lesser Antilles, Caribbean, is redescribed. Females of the new species differ from H. paradoxa males (apparently there are no known females of H. paradoxa) in their larger size, in the density and type of setation on the carapace and legs, in having smaller eyes relative to the carapace, and in having relatively stouter appendages. Males of the new species are similar in size and general shape to females, but differ markedly from them most notably by lacking the density and type of setation seen in the females; in this regard they are similar to males of H. paradoxa. Males ofthe new species differ from males of H. paradoxa mostly in the relative size of the eyes, admittedly a character that could change during ontogeny. The question of sexual dimorphism is raised as concerns these two species vs other members of the genus (notably H. robertsi Garth) and members of the other homolodromiid genus, Dicranodromia A. Milne Edwards, for both of which little or no sexual dimorphism is known.