Zygopa Holthuis, 1961: 21

BOYKO, CHRISTOPHER B., 2002, A Worldwide Revision Of The Recent And Fossil Sand Crabs Of The Albuneidae Stimpson And Blepharipodidae, New Family (Crustacea: Decapoda: Anomura: Hippoidea), Bulletin of the American Museum of Natural History 2002 (272), pp. 1-396 : 203-204

Zygopa Holthuis, 1961: 21 . – Serène and Umali,

1965: 108–109. – Rodriguez, 1980: 238. –

Coêlho and Calado, 1987: 41. – Manning,

1988: 626–627 (list). – Calado, 1995: 277.

DIAGNOSIS: Carapace wider than long, front narrow; anterior margin unarmed; hepatic anterolateral spine present; branchiostegite unarmed. Rostrum absent. Ocular peduncles cylindrical, reduced, fused, corneas reduced. Antennular segment I unarmed; dorsal flagellum with 17–22 articles, ventral flagellum with one to three articles. Antennal segment I unarmed; acicle long; flagellum with one article. Maxilliped II exopod with flagellum. Maxilliped III carpal projection short; merus unarmed; crista dentata absent; exopod lamelliform, without flagellum. Pereopod I dactylus with dorsal margin crenulate; distodorsal carpal spine absent; cutting edge bluntly toothed. Pereopods II–IV dactyli with rounded heels; dorsal margins of carpi smooth. Males without small coxal pore on pereopod III. Abdomen without pleura on somite V. Telson of male elongate, triangular, fully calcified. Telsons strongly sexually dimorphic.

DISTRIBUTION: Known from the Caribbean Sea, Gulf of Mexico, the Philippines, and New Caledonia.

TYPE SPECIES: Zygopa michaelis Holthuis, 1961 , by monotypy.

INCLUDED SPECIES: Z. michaelis Holthuis, 1961 ; Z. nortoni Serène and Umali, 1965 .

REMARKS: This genus is closer to Albunea than to Lepidopa , and it is clearly a member of the Albuneinae , despite the presence of the Lepidopa ­like anterolateral carapace spine. In fact, the genus Paralbunea is closer to Lepidopa than Zygopa is, and that genus has always been closely allied to Albunea (e.g., Serène, 1979). The sister taxon to Zygopa is Squillalbunea , n. gen., which shares many characters with this genus, including a narrow anterior carapace margin with low rounded granules instead of acute spines, a rugose dorsal margin on the dactylus of pereopod I, and elongate, fully calcified male and female telsons. The two species of Zygopa are from opposite sides of the world, but are nevertheless extremely difficult to separate even when examined side by side. This suggests that little divergence has taken place within this genus, despite the duration and distance for which the species have been separated.