A new species of Ventojassa (Crustacea: Amphipoda: Corophiidea: Ischyroceridae) from the Beagle Channel, Argentina

ALONSO, G.M.; CHIESA, I.L.

Coquimbo

Congreso; The Crustacean Society Mid-Year Meeting; 2007

Universidad Católica del Norte y Universidad Andres Bello, Chile

Ventojassa Barnard, 1970 is composed of six species distributed in Australia, New Zealand, Madagascar, Korea and southern California. Vader and Myers (1996) pointed out that the poorly described and figured V. georgiana (Schellenberg, 1931) cited from southern Tierra del Fuego, Magellan Straits, Antarctica and sub-Antarctic islands could not belong with this genus and they provisionally transferred the species to a new genus (Ruffojassa). Ventojassa is distinguished by accessory flagellum well developed; coxae 1-5 of similar depth; coxa 4 not excavate posteriorly; uropod 3 peduncle lacking setae or with fine setae on its outer margin, outer ramus recurved apically, bearing 1-3 wire setae and telson with two or more subapical cusps. Ventojassa sp. nov., collected in the Beagle Channel, northern of Despard Island (54º 52'S 68º10'W) at 8-12 m depth, was associated to holdfasts of Macrocystis pyrifera. It is characterized by head with lateral cephalic lobes triangular and apically acute; eyes located far from the apex of ocular lobes; maxilla 1, inner plate naked; gnathopod 1 propodus shorter than carpus; female gnathopod 2 much stronger than 1, carpus subtriangular, very short, propodus subquadrate; male gnathopod 2 stouter than in female, carpus short, saucer-like, propodus very robust, quadrate, with a slight round process at the palmar corner,medially excavated and with a large process subdistally; peraeopod 6 much more longer than 5, and 7 longer than 6; uropod 3, outer ramus with one wire-like seta on outer margin; telson with well developed submarginal cusps. The new species is separated from all Ventojassa species by the shape of the acute cephalic lobes, the location of eyes far from ocular lobe apex, and numerous telsonic subapical cusps. If future studies confirm that V. georgiana must be assigned to Ruffojassa, Ventojassa sp. nov. would be the unique species belonging to this genus recorded from South America.