Probolisca ovata ( Stebbing, 1888 )

Alonso, G. M., 2012, Amphipod crustaceans (Corophiidea and Gammaridea) associated with holdfasts of Macrocystis pyrifera from the Beagle Channel (Argentina) and additional records from the Southwestern Atlantic, Journal of Natural History 46 (29 - 30), pp. 1799-1894 : 1889-1891

Probolisca ovata ( Stebbing, 1888)

Metopa ovata Stebbing, 1888: 764–767 , pl. 44. Probolisca ovata: Thurston, 1974a: 26–27 , fig. 8c–j; Chiesa et al., 2005: 169, 171, tb. 2; De Broyer et al., 2007: 213.

Material examined

Argentina; Beagle Channel, northern Isla Despard , 54 ◦ 52 ′ S, 68 ◦ 10 ′ W, 8–12 m depth, colls. D. Aureliano and A. Ferlito, don. G. Lovrich: 1 ♀ 3 mm, 1 November 1999, MACN-In 38792; 3 ovig. ♀♀ 3–3.5 mm, 10 November 1999, MACN-In 38793; 1 ovig. ♀ 3 mm, 2 May 2000, MACN-In 38794. Same location, same colls., 29 May 2000: 1 ♂ 2.5 mm, MACN-In 38795a; 1 ovig. ♀ 3 mm, MACN-In 38795b .

Remarks

Probolisca ovata ( Stebbing, 1888) is widely distributed in the Southern Ocean, from west and east Antarctica, sub-Antarctic islands and the Magellanic area, reaching north of Argentina (about 37 ◦ S). Krapp-Schickel (2009) found this species at Snares Islands and in the Tasman Sea. Its presence in holdfasts of M. pyrifera in the Beagle Channel shows a new habitat. Arnaud (1974) had mentioned P. ovata inhabiting holdfasts from the Kerguelen Islands.

Distributional notes

The prevalence or rarity and the frequency of each species found in the Southwestern Atlantic, is shown in Table 1. The distribution of Tryphosites chevreuxi was enlarged from Tierra del Fuego to Uruguay, whereas Austroregia huxleyana and Gondogeneia thurstoni occur all along the Argentine Sea; Tryphosella schellenbergi , Microphoxus cornutus and Fuegiphoxus fuegiensis are only found in the Southwestern Atlantic, where they are well represented, but the two first species were not found in the Santa Cruz area whereas the latter species does not occur in the Chubut area. The remaining species were reported from one, two or three combined geographical areas, regardless of how distant they were.

The present work reports 36 amphipod species associated with the holdfasts of the kelp M. pyrifera from the Beagle Channel. The known distribution in the Southwestern Atlantic Ocean is enlarged for 14 of these species. The seven new species herein described and also Lembos argentinensis , Gammaropsis (Gammaropsis) deseadensis , Liljeborgia octodentata and Uristes yamana are endemic to the Argentine Sea and widely found in the Magellanic area; the new records widened the latitudinal range of Lembos argentinensis and Liljeborgia octodentata to include about 42 ◦ S. Iphimedia multidentata , Pseudiphimediella glabra , Orchomenella (Orchomenopsis) chilensis , Gondogeneia gracilicauda and Gondongeneia macrodon are also endemic to the Magellanic area, but they occur in both the South Pacific and South Atlantic Oceans.

A few species, e.g. Austroregia huxleyana and Haplocheira barbimana robusta , are mainly found in the Magellanic area but they reach the north of Argentina (Río Negro-Buenos Aires area). On the other hand, Tryphosella schellenbergi , Tryphosites chevreuxi and Microphoxus cornutus , which are also present in the Magellanic area, are distributed northwards up to Buenos Aires in Argentina, Uruguay, Brazil and Valparaíso in Chile.

Gammaropsis (Paranaenia) typica , Bircenna fulva and Crassicorophium bonnellii were recorded in the Magellanic area, but they have extralimital distributions, in the north of Argentina as well as in foreign locations.

Three species, Amphilochus marionis , Peramphithoe femorata and Parawaldeckia kidderi were reported from the Magellanic area and sub-Antarctic islands, also showing extralimital distributions in the north of Argentina and foreign locations.

Paraphimedia normani and Seba subantarctica are distributed in the Magellanic area and Antarctic Peninsula.

Jassa alonsoae is widely reported from the Magellanic area, sub-Antarctic islands and Antarctica, whereas the remaining species ( Eusirus antarcticus , Atyloella magellanica , Fuegiphoxus fuegiensis , Seba saundersii and Probolisca ovata ) have similar biogeographical distribution as the former taxon but are also found in the north of Argentina and foreign locations.