Notes on the genus Ethusa Roux, 1828, and description of Ethusa steyaerti n. sp. (Crustacea, Decapoda, Dorippidae), from the continental shelf of the Gulf of California, Mexico

Abstract

On the basis of the morphology of male pleopods, two American Ethusa Roux formerly recognized as subspecies of Ethusa mascaronc (Herbst) from the Mediterranean, are given species rank : E. americana A. Milne Edwards, from the west Atlantic and E. panamensis Finnegan from the east Pacific. During trawling operations on the continental shelf of the Gulf of California, Mexico, numerous specimens of E. lata Rathbun and E. ciliatifrons Faxon were collected. A new species of Ethusa was also found at two localities in the Central Gulf and represents the fourth species of Ethusa known for the eastern Pacific. Resume. L'examen detaille des pleopodes males de deux Ethusa Roux americaines, designees jusqu'a ce jour comme sous-especes de Ethusa mascaronc (Herbst) de la Mediterranee, permet de leur donner le rang d'espece : E. antcricana A. Milne Edwards, de TAtlantique ouest, et E. panamensis Finnegan, du Pacifique est. D'autre part, des chalutages realises le long de la plate-forme continentale du golfe de Californie, Mexique, ont permis de recolter de nombreux specimens d'Ethusa, y compris deux especes connues, E. lata Rathbun et E. ciliatifrons Faxon, et une nouvelle espece capturee dans deux localites du Golfe central. Celle-ci est decrite et represente done la quatrieme espece du genre connue pour les cotes du Pacifique est. M. HINDRICKX, Estacion Mazatlun UNAM, A.P. 811, Mazatldn, 8200 Mexico.