Ovalipes ocellatus
Ovalipes ocellatus, commonly known as the lady crab, oscellated crab, or calico crab, is a species of crab in the family Ovalipidae.
Description
The carapace of O. ocellatus is slightly wider than long, at wide, and long. The carapace is yellow-grey or light purplish, with "leopardlike clusters of purple dots". It exhibits a limited iridescence as a form of signalling.
Taxonomy
Ovalipes ocellatus is commonly known as the lady crab, oscellated crab, or calico crab. It was first described in 1799 by naturalist Johann Friedrich Wilhelm Herbst, who placed it into the genus Cancer. In 1898, carcinologist Mary Jane Rathbun moved the species to her new genus Ovalipes. O. ocellatus is part of a distinct group of Ovalipes which also includes O. floridanus, O. iridescens, O. molleri, and O. stephensoni. O. ocellatus is almost identical to O. floridanus, which lives in the Gulf of Mexico, but can be separated from the sympatric O. stephensoni by purple spots which O. stephensoni lacks. The following cladogram based on morphology shows the relationship between O. catharus and the other extant species of Ovalipes:
Distribution
The distribution of Ovalipes ocellatus extends along North America's Atlantic coast from Canada to Georgia. O. ocellatus is "probably the only Ovalipes species common north of Virginia", being replaced by Ovalipes stephensoni to the south.
Diet
The diet of Ovalipes ocellatus consists predominantly of bivalves, crustaceans including other crabs, polychaetes, cephalopods, and gastropods. It rarely feeds on fish.
Ovalipes ocellatus has five zoeal (larval) stages, lasting a total of 18 days at and a salinity of 30‰, and 26 days at and 30‰.
Ecology
Ovalipes ocellatus is nocturnal and often buries itself in the sand. It has been described as "vicious" and "the crab most likely to pinch a wader's toes".