Clear Sponge Shrimp

Periclimenaeus wilsoni (Hay)

Coralliocaris wilsoni Hay, 1917:71.

Periclimenaeus wilsoni.—Holthuis 1951b: 103, pl. 31, pl. 32: figs. b, c.—Williams 1965b :46, fig. 38.

TYPE-LOCALITY.—Fishing grounds, 20 miles off Beaufort Inlet, North Carolina.

DISTRIBUTION.—Off Beaufort, North Carolina, Alligator Harbor and Dry Tortugas, Florida, commonly in sponges; to a depth of 73 meters.

*Genus Periclimenes Costa, 1844

Subgenera based on the presence (Periclimenes) or absence (Harpilius) of an accessory denticle on the flexor margin of the dactyls of the three posterior pereiopods are not recognized here. The groups separated by this character do not seem to be otherwise homogeneous, and the character has lost the practical value it may once have had. The species now known display an uninterrupted series from those with no accessory denticle, through those with a denticle that can be discerned only under high magnification, to those with clearly biunguiculate dactyls, and the complete range has been noted (Holthuis 1951b) in at least one single species (P. iridescens).

At the suggestion of A. J. Bruce, I have examined specimens of all of the western Atlantic species of Periclimenes (with the exception of P. pauper) for the presence of a slender sternal spine between the coxae of the first pereiopods. According to Bruce (in litt.), such a spine is present in several free-living, predatory species in the Indo-Pacific region. Of the western Atlantic species, the sternal spine was found only in P. americanus, but there is a median triangular projection on that sternite in P. rathbunae and a pair of such projections in P. paivai.