Two New Species of Sponge-Dwelling Snapping Shrimp from the Belizean Barrier Reef, with a Synopsis of the Synalpheus brooksi Species Complex

Kenneth S Macdonald,J Emmett Duffy

doi:10.1206/0003-0082(2006)3543[1:tnsoss]2.0.co;2

Abstract

Two new species of sponge-dwelling snapping shrimp in the genus Synalpheus are described. Synalpheus carpenteri is based on specimens collected from the Belizean Barrier Reef, the Exuma Islands of the Bahamas, and the Atlantic Coast of Panama, while Synalpheus ruetzleri is based on specimens collected from the Belizean Barrier Reef and the Atlantic Coast of Panama. Both species belong to a group of closely related shrimp (the ‘‘Synalpheus brooksi complex’’) that includes Synalpheus brooksi, Synalpheus bousfieldi, Synalpheus chacei, and possibly additional undescribed species. All species in the complex are remarkably similar in morphology, but Synalpheus carpenteri is readily recognizable by its brilliant orange color in life, its habitation solely in sponges of the genus Agelas, its squat, wide-based telson, and the short lateral spines of its scaphocerite and basicerite. Synalpheus ruetzleri appears unique within the complex in possessing a well-developed blade on the scaphocerite. Specimens of Synalpheus brooksi and S. bousfieldi from Belize and other localities are also figured to facilitate separation of members of the brooksi complex.

Highlights

Snapping shrimp in the genus Synalpheus Bate, 1888 are diverse components of the cryptic fauna of coral reefs and other tropical marine ecosystems worldwide (Felder and Chaney 1979; Reed et al, 1982)
In the western Atlantic, the genus Synalpheus is dominated by species in the Gambarelloides group (Coutiere, 1909; Dardeau, 1984), a monophyletic clade (Morrison et al, 2004) that is largely endemic to that region
We have occasionally found specimens that we consider to be S. bousfieldi inhabiting Agelas sp., but they are distinguishable from S. carpenteri in their overall dull color, narrow telson, and relatively long basicerite and scaphocerite lateral spines

Summary

INTRODUCTION

Snapping shrimp in the genus Synalpheus Bate, 1888 are diverse components of the cryptic fauna of coral reefs and other tropical marine ecosystems worldwide (Felder and Chaney 1979; Reed et al, 1982). The genus includes more than 150 species (Chace, 1988; Rıos, personal obs.) that inhabit the interstices of coral rubble, the internal spaces of sponges, and, in the Indo-Pacific, the arms of crinoid echinoderms (Beebe, 1928; Pearse, 1932; Bruce, 1976; Duffy, 1992). These shrimp are small (usually ,2 cm in length) and reclusive and are often among the most abundant cryptofaunal macroinvertebrates in reef envi-. Both species have been considered highly variable morphologically, but recent work indicates that much of this variation is attributable to distinct, morphologically cryptic species, including S. chacei and the two new species in the brooksi complex described

MATERIALS AND METHODS

DISCUSSION