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.