Paraleptopentacta, Mezali & Thandar & Khodja, 2020

Mezali, Karim, Thandar, Ahmed S. & Khodja, Ihcene, 2020, Paraleptopentacta, a new Mediterranean and north-west Atlantic sea cucumber genus, with the first record of P. tergestina n. comb. (Echinodermata Dendrochirotida: Cucumariidae) from the north-western Algerian coast, Zootaxa 4860 (2), pp. 199-210 : 205

Genus Paraleptopentacta n. gen.

Cucumaria (partim) Sars, 1859: 132.

Trachythyone (partim) Panning, 1949: 426.

Leptopentacta (partim) Panning, 1966: 56.

Type species. Cucumaria elongata Düben & Koren, 1846 (herein designated).

Other species included herein. L. cucumis ( Risso, 1826) ; L. tergestina ( Sars, 1859) ;? L. djakonovi Baronova & Savel’eva, 1972; (? L. nova Deichmann, 1941 is excluded from further consideration—see above).

Diagnosis. A genus of Cucumariidae with an elongated, usually curved body. Tentacles and tube feet as in Leptopentacta above. Calcareous ring usually without posteriorly forked radial plates in combination with body wall ossicles as an external layer of baskets (sometimes absent) and an inner layer of smooth or slightly knobbed single-layered multilocular plates, rarely one or two plates reticulate (in P. cucumis ).

Etymology (Gk). para—along side or parallel to.

Remarks. This genus is here erected to accommodate all Mediterranean species (sometimes extending into the North-West Atlantic) of the former Leptopentacta group. It is clearly differentiated from the tropical genus Leptopentacta (s.s.) on the basis of the presence of nearly always smooth plates in the body wall, usually accompanied by baskets of various forms. In one species ( P. djakonovi ) large plates secondarily knobbed.