On two shallow-water Paramunnids (Isopoda: Asellota) from the South-West Atlantic Ocean

ROCCATAGLIATA, D.; DOTI, B.L.

Florianópolis, Santa Catarina, Brasil

Congreso; 3rd Brazilian Crustacean Congress and 2004 TCS Summer Meeting; 2004

"The Brazilian Crustacean Society" y "The Crustacean Society"

The shallow-water Asellota isopods from the South-West Atlantic are scarcely known. In order to improve our knowledge about this fauna two paramunnids are herein described: Austrosignum fuegiae n. sp. and Abyssianira cf. argentenensis Menzies, 1962. The former species was collected at 15-35 m depth in the Beagle Channel whereas the latter was collected at 129 m depth off the Río de la Plata Estuary. Austrosignum fuegiae n. sp., and the members of the genus Abyssianira Menzies, 1956 have a distinctive antenna: the third article of the peduncle is not much longer than broad, has a proximal lateral bulge and is about as long as articles one and two combined. A. fuegiae n. sp. is readily distinguished from all the species of Abyssianira by having well-developed eyes, head with a smooth frontal margin and uropods without a peduncle. Although A. fuegiae n. sp. does not show any unique morphological character, its particular mixture of features suggests that this species might need a new genus. The genus Abyssianira includes four species, all of them collected at abyssal and bathyal depths (400-5293 m). The finding of A. cf. argentenensis off Buenos Aires Province is the first record of a member of Abyssianira in shallow waters. This research was supported by the ANPCyT (PICT 11.180).