A new species of Oradarea (Crustacea: Amphipoda: Calliopiidae) from the Beagle Channel, Argentina

CHIESA IGNACIO LUIS; ALONSO GLORIA MARÍA

Gramado, RS, Brasil

Congreso; V Congresso Brasileiro sobre Crustáceos; 2008

Universidade Federal do Rio Grande do Sul (UFRGS) & Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS)

Oradarea Walker, 1903 comprises fifteen known species, thirteen from the Antarctic and sub-Antarctic islands, and two from the tropical Indo-West Pacific. Oradarea sp. nov., thus represents the first species of the genus found in the Magellan area. The specimens were collected in the Beagle Channel, northern of Despard Island (54º 52´S 68º10´W) at 8-12 m depth and were associated to holdfasts of Macrocystis pyrifera. It is characterized by head with prominent lateral cephalic lobes rounded; anteroventral margin acutely produced; eyes large, subrounded, major diameter 0.48 times height of head; antennae slender, very long; gnathopod 2, propodus appreciably longer than carpus, slightly expanded distally; palm excavate, palmar angle well defined; peraeopods rather slender, elongate, seventh longer than sixth; epimeron 3, ventral and posterior margins convex, posteroventral corner with acute tooth immediately above it concave margin; peraeonite 7, dorsal edge free from pleonite 1, convex, with small obtuse tooth; pleonites 1 and 2 each produced dorsally into a sharp tooth; integument with long scales on pleosome; telson longer than broad, lateral margins somewhat concave, apex rounded, crenellate. Oradarea sp. nov. can be separated from all the known species by the combination of the following morphological characters: shape of lateral cephalic lobes, anteroventral margin of head, gnathopod 2 propodus, dorsal margin of peraeonite 7 and pleonites 1 and 2, epimeron 3 and telson. This research was partially supported by CONICET. Key words: New amphipod, Tierra del Fuego, Argentine Sea