O objetivo deste trabalho é redescrever 11 espécies de esponjas coletadas através do Programa Antártico Brasileiro (PROANTAR), nas Is. Shetland do Sul e áreas próximas. Nnovas informações são fornecidas acerca do conhecimento da fauna de poríferos da Antártica, tanto para a riqueza específica como para os dados referentes às distribuições geográfica e batimétrica das espécies identificadas. As seguintes espécies foram identificadas e são aqui ilustradas e amplamente descritas: Cinachyra antarctica (Carter, 1872), Cinachyra barbata Sollas, 1886, Craniella leptoderma (Sollas, 1886), Tethyopsis longispinum (Lendenfeld, 1907), Polymastia invaginata Kirkpatrick, 1907, Homaxinella balfourensis (Ridley & Dendy, 1886), Suberites montiniger Carter, 1880, Halichondria (Eumastia) attenuata (Topsent, 1915), Haliclona (Soestella) chilensis (Thiele, 1905), Hemigellius bidens (Topsent, 1901) and Calyx arcuarius (Topsent, 1913). Duas espécies são pela primeira vez registradas para o continente antártico, Halichondria (Eumastia) attenuata (Topsent, 1915) e Haliclona (Soestella) chilensis (Thiele, 1905), enquanto que Tethyopsis longispinum (Lendenfeld, 1907), S. montiniger Carter, 1880 e Hemigellius bidens (Topsent, 1901) apresentam o primeiro registro para este setor do continente. Ampliam-se ainda os dados batimétricos para T. longispinum e H. attenuata.

The aim of this work is to redescribe 11 species of sponges collected through the Brazilian Antarctic Program (PROANTAR), at the South Shetland Islands and vicinity. New information is provided on the Antarctic sponge fauna, in regard to species richness and the geographical and bathymetric distributions of identified species. The following species were identified and are here illustrated and fully described: Cinachyra antarctica (Carter, 1872), Cinachyra barbata Sollas, 1886, Craniella leptoderma (Sollas, 1886), Tethyopsis longispinum (Lendenfeld, 1907), Polymastia invaginata Kirkpatrick, 1907, Homaxinella balfourensis (Ridley & Dendy, 1886), Suberites montiniger Carter, 1880, Halichondria (Eumastia) attenuata (Topsent, 1915), Haliclona (Soestella) chilensis (Thiele, 1905), Hemigellius bidens (Topsent, 1901) and Calyx arcuarius (Topsent, 1913). Two new records are given for the Antarctic continent: Halichondria (Eumastia) attenuata (Topsent, 1915) and Haliclona (Soestella) chilensis (Thiele, 1905). Tethyopsis longispinum (Lendenfeld, 1907), Suberites montiniger Carter, 1880 and Hemigellius bidens (Topsent, 1901) represent the first records for this sector of the continent. Bathymetric data are extended for T. longispinum and H. attenuata.

No presente estudo 16 espécies são registradas para as Ilhas Shetland do Sul e áreas próximas: Acanthorhabdus fragilis Burton, 1929, Iophon unicornis Topsent, 1907, Clathria (Axosuberites) flabellata (Topsent, 1916), Clathria (Axosuberites) nidificata (Kirkpatrick, 1907), Kirkpatrickia variolosa (Kirkpatrick, 1907), Myxodoryx hanitschi (Kirkpatrick, 1907), Iotroata somovi (Koltun, 1964), Tedania (Tedaniopsis) charcoti (Topsent, 1907), Tedania (Tedaniopsis) vanhoffeni (Hentschel, 1914), Tedania (Tedaniopsis) oxeata (Topsent, 1916), Isodictya kerguelenensis (Ridley & Dendy, 1886), Isodictya lankesteri (Kirkpatrick, 1907), Isodictya toxophila Burton, 1932, Isodictya bentarti Ríos, Cristobo & Urgorri, 2004, Latrunculia (Latrunculia) brevis Ridley & Dendy, 1886 e Latrunculia (Latrunculia) biformis (Kirkpatrick, 1908). Dentre as espécies identificadas, cinco são novas ocorrências para a região estudada, três têm seu limite batimétrico ampliado e as demais são confirmadas para a área de estudo.

In the present study 16 species are registered for the South Shetland Islands and vicinity: Acanthorhabdus fragilis Burton, 1929, Iophon unicornis Topsent, 1907, Clathria (Axosuberites) flabellata (Topsent, 1916), Clathria (Axosuberites) nidificata (Kirkpatrick, 1907), Kirkpatrickia variolosa (Kirkpatrick, 1907), Myxodoryx hanitschi (Kirkpatrick, 1907), Iotroata somovi (Koltun, 1964), Tedania (Tedaniopsis) charcoti (Topsent, 1907), Tedania (Tedaniopsis) vanhoffeni (Hentschel, 1914), Tedania (Tedaniopsis) oxeata (Topsent, 1916), Isodictya kerguelenensis (Ridley & Dendy, 1886), Isodictya lankesteri (Kirkpatrick, 1907), Isodictya toxophila Burton, 1932, Isodictya bentarti Ríos, Cristobo & Urgorri, 2004, Latrunculia (Latrunculia) brevis Ridley & Dendy, 1886 and Latrunculia (Latrunculia) biformis (Kirkpatrick, 1908). Amongst the identified species, five are new occurrences for the studied region, three have their bathymetric limit extended and the others are confirmed for the studied area.

Horticultural production areas are favorable to development and maintenance of land mollusks populations. To know the mollusk fauna diversity in that kind of production area a research project was conduced in a rural-urban district of Porto Alegre, Rio Grande do Sul, Brazil. The production property studied is located in the Southern zone of the city and has 17 ha of cultivated area. The sampling period was from August/2000 to August/2001, with monthly quantitative collects on the different culture production beds previously selected. Six taxa were registered: Deroceras leave (Müller, 1774) (1.389 specimens = 82,82%), Bradybaena similaris (Férussac, 1821) (195 specimens = 11,7%), Succinea meridionalis d'Orbigny, 1846 (82 specimens = 4,9%), Lamellaxis gracilis (Hutton, 1834) (03 specimens = 0,17%), Bulimulus (Bulimulus) vesicalis angustus Weyrauch, 1966 (05 specimens = 0,3%) and Megalobulimus abbreviatus (Bequaert, 1948) (02 specimens = 0,11 %), only the last two being natives.

Neocorbicula limosa (Maton, 1811) is the only species of that South American genus that occurs in the hydrographic basins of Rio Grande do Sul State, Brazil. Seasonal quantitative collections between 1995 and 1996 in the lake Guaiba were accomplished, with the aim to know the reproductive dynamics and environmental preferences of populations of N. limosa. A substratum constituted by medium to coarse sands at an 'average depth around 2m shown to be favorable to installation of population of N. limosa. The largest population density (2.496 ind./m²) was registered in summer. Embryos at various development phases were registered inside individuals. The shell sizes of these individuals started from 8mm in length. The embryo's size could reach ¼ of the shell-mother's size, and their liberation occurs through the rupture of the gills.