Genus Costacopluma Collins & Morris, 1975

TYPE SPECIES. — Costacopluma concava Collins & Morris, 1975, by original designation.

INCLUDED SPECIES. — Costacopluma australis Feldmann, Casadío, Chirino-Gálvez & Aguirre-Urreta, 1995; C. bifida Collins, Higgs & Cortitula, 1994; C. bishopi Vega & Feldmann, 1992; C. binodosa Collins & Wienberg Rasmussen, 1992; C. concava Collins & Morris, 1975; C. grayi Feldmann & Portell, 2007; C. maroccana Ossó-Morales, Artal & Vega, 2010; C. mexicana Vega-Vera & Perrilliat, 1989; C. mamethioupamei Hyžný, Perrier, Robin, Martin & Sarr, 2016; C. nicksabani n. sp.; C. nordestina Feldmann & Martins-Neto, 1995; C. salamanca Feldmann, Rodriguez, Martinez & Aguirre-Urreta, 1997; C. squiresi Nyborg, Vega & Filkorn, 2023; C. texana Armstrong, Nyborg, Bishop, Ossó-Morales & Vega, 2009; C. senegalensis (Rémy in Gorodiski & Rémy, 1959).

DIAGNOSIS. — Small rectangular to ovoid carapace, wider than long; carapace surface distinctly flattened and traversed by three elevated, granular ridges, the anteriormost being complete and often biconvex forwards; posterior two ridges converging axially defining depressed, triangular to rectilinear, smooth mesobranchial region. Rostrum generally narrow, downturned, bilobed. Carapace flanks distinct, about perpendicular to dorsal surface and separated from it by beaded rim. Sternum broad, with well-defined sternites; sternites 5-7 each with prominent transverse, beaded ridge; male sternopleonal cavity deep, reaching end of sternite 4. Transverse ridges also present on pleonal somites. Pereiopod 5 subdorsal, reduced. Emended from Feldmann et al. (2014: 137).