Dana, 1852
Carapace elongate, slender, separated by cervical groove into long anterior (gastric) and short posterior (cardiac) region. Rostrum little developed, nearly always unspined. Without pleurobranchs. Ocular peduncles more or less dorsoventrally depressed, contiguous, cornea usually subdistal. Antennal scales reduced. First maxilliped with large foliaceous exopodite, nonflagellated, reduced endopodite and well-developed epipodite generally composed of anterior and posterior lobe; second often foliaceous exopodite and epipodite reduced or absent; third frequently without exopodite, endopodite pediform, subpediform or operculiform and epipodite reduced or absent. First legs chelate, usually unequal; second legs chelate; third simple; fourth simple or subcheliform; fifth subchelate or chelate. Pleopods 1 and 2 present in both sexes (except some males), 3-5 foliaceous, provided with appendix interna.
Recent studies of the family do not agree on the number of genera to be recognized. De Saint Laurent (1973, 1979) divided the family into 9 genera, while Poore and Griffin (1979) only recognized three, as several of their species of Callianassa s.l. could not be assigned with confidence to any of De Saint Laurent's genera. Poore and Griffin therefore only recognized the genera Callianassa Leach, 1814, Ctenocheles Kishinouye, 1926, and Gourretia De Saint Laurent, 1973, and placed all the other genera recognized by De Saint Laurent in the synonymy of Callianassa. Recently, Manning and Felder (1986: 437-443) redefined the genus Callichirus Stimpson, 1866, placing in it 4 species formerly assigned to Callianassa; they convincingly showed Callichirus to be distinct from Callianassa s.l. None of the four species at present known to belong to Callichirus has been reported to be of economic importance.
Without taking a definite stand on the generic taxonomy of the Callianassidae, I recognize here, for purely practical reasons, only the genera Callianassa, Callichirus, Ctenocheles and Gourretia. All species reported to be of interest to fisheries belong to the genus Callianassa s.l. as accepted here.