PROC. BIOL. SOC. WASH. 104(2), 1991, pp. 299-308 CHIROSTYLID AND GALATHEID CRUSTACEAN ASSOCIATES OF COELENTERATES AND ECHINODERMS COLLECTED FROM THE JOHNSON-SEA-LINK SUBMERSIBLE, INCLUDING A NEW SPECIES OF GASTROPTYCHUS A. L. Rice and J. E. Miller Abstract.— A. new species of chirostylid decapod crustacean, Gastroptychus Salvador!, is described from a specimen collected in association with a brisingid starfish by submersible off the Bahamas. A number of other chirostylids and galatheids, collected together with their echinoderm associates in the tropical and sub-tropical western Atlantic, are also reported. Some of these associations were previously unsuspected. The collections suggest that at least some of the decapods live together as mated pairs on their hosts. Traditional benthic sampling gears such as trawls and dredges disrupt any but the most robust associations between different animal species. Nevertheless, there are nu-merous reports in the literature of behav-ioural associations between decapod crus-taceans and other benthic organisms, particularly coelenterates, sponges and echi-noderms. Moreover, evidence for such as-sociations has been found even in the fossil record (Bishop & Portell 1989). Most of these records are from relatively shallow regions, but the use of manned submersibles permits observations of such associations to be extended to deeper waters, and par-ticularly to areas where the use of more con-ventional sampling techniques is precluded. Observations, photographs and collections made from the Johnson-Sea-Link (JSL) submersibles (Harbor Branch Oceano-graphic Institution, Inc.) in the tropical and sub-tropical western Atlantic during recent years have already provided data on asso-ciations between pontoniine shrimps and deep sea echinoids (Bruce 1986a, 1986b; Berggren & Svane 1 989). This paper reports a small collection of galatheoid crustaceans secured along with their associates during these and other dives off the Caribbean is-lands of Barbados and St. Vincent. Material described herein has been deposited at the National Museum of Natural History, Smithsonian Institution (USNM) and the Harbor Branch Oceanographic Museum (HBOM). Family Chirostylidae Gastroptychus Salvador! , new species Figs. lA-D; 2B, D, F Material. — 1 ovig. female (holotype USNM 239278)JSL-I-2264, off San Sal-vador Island, Bahamas, 24°03.6rN, 74°33.37'W, 13 Sep 1988, 874 m, associ-ated with the brisingid starfish Novodinia antillensis (A. H. Clark). Description. (Figs. 1, 2)— Carapace length excluding rostrum slightly more than great-est breadth. Branchial regions inflated so that carapace narrows both anteriorly and posteriorly. Rostrum slender, upturned, more than '/s length of remainder of cara-pace. Linea anomurica distinct, almost straight; beneath it carapace flanks more or less even-ly covered with small spines except for a small, naked, depressed area immediately above insertion of cheliped.