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Molluscs collected in five localities in the State of Rio Grande do Sul (Brazil) were digested and examined. The infected slugs were identified as Phyllocaulis variegatus and the larvae found were inoculated per os into mice. After 50 days, worms with the caracteristics of Angiostrongylus costaricensis were recovered from the mesenteric arterial system. The results establish the role of P. variegatus as intermediate host of A. costaricensis in south Brazil, where many cases of abdominla angiostrongyliasis have been diagnosed.

Se presenta una lista parcial de gasterópodos terrestres Punctoideos del "Centro de Pesquisas e Conservação da Natureza Pró-Mata" (São Francisco de Paula, Estado de Rio Grande do Sul, Brazil) (CPCN-PM). Esta lista incluye siete especies, dos de ellas son nuevas. El CPCN-PM se localiza entre los 600 y 950 m de altitud; presenta clima templado superhúmedo a húmedo, lluvias de 2.250 mm anuales y temperatura promedio anual de 14,5ºC; están presentes tres regiones fitoecológicas principales, floresta ombrófila mixta, floresta ombrófila densa y sabana. Los taxones hallados son: Rotadiscus amancaezensis (Hidalgo, 1869), Lilloiconcha tucumana (Hylton Scott, 1963), Radiodiscus cuprinus Fonseca & Thomé, 2000, Radiodiscus tenellus Hylton Scott, 1957, Radiodiscus promatensis sp. nov., Zilchogyra gordurasensis (Thiele, 1927) y Zilchogyra zulmae sp. nov. La conchilla de R. promatensis sp. nov. es muy pequeña, casi plana, con ombligo muy desarrollado, abertura reniforme, con estrías espirales en la teleoconcha y 58-62 costillas axiales en el último anfracto. La conchilla de Z. zulmae sp. nov. es troquiforme alta, con cinco anfractos con fuertes y espaciadas costillas axiales (25-38), ombligo amplio y perspectivo y abertura subcircular angulosa. La fauna de gasterópodos carópidos del CPCN-PM tiene tres especies conocidas sólo del área (R. cuprinus, R. promatensis sp. nov. y Z. zulmae sp. nov.), una, que se distribuye también en Paraguay (R. tenellus) y tres (L. tucumana, R. amancaezensis y Z. gordurasensis), comunes a otras áreas de América del Sur, principalmente la región de las Yungas.

Our main objectives were investigate the phylogenetic relationships between the species of the land slug Phyllocaulis and the monophyly of the genus based on mitochondrial (16S and COI) and nuclear (ITS2) DNA sequences from multiple individuals from each species. Evolutionary trees were constructed using Bayesian inference, maximum likelihood, maximum parsimony and neighbor-joining methods. All species accepted in the current taxonomy based on penial characteristics and radular measurements were reciprocally monophyletic. Five species out of six formed a clade with the following highly supported relationship: Phyllocaulis gayi, Phyllocaulis soleiformis, Phyllocaulis renschi, Phyllocaulis variegatus, Phyllocaulis boraceiensis. The position of Vaginulus taunaisii changed according to the analysis, appearing as sister-group of Phyllocaulis or as sister-group of Phyllocaulis tuberculosus. Divergence times estimated from the 16S tree indicated that the extant species of Phyllocaulis shared a common ancestor around 1.3 Ma and that most species originated between 0.8 and 0.6 Ma.

Veronicellid slugs are the main intermediate hosts for Angiostrongylus costaricencis. In a rural locality in Nova Itaberaba (SC, southern Brazil) Sarasinula linguaeformis was identified as a crop pest. The parasitological examination revealed A. costaricencis infection in 43 out ot 50 slugs. The prevalence of 86% and the individual parasitic burdens are the highest sofar reported in Brazil and S. linguaeformis is the first species from the genus Sarasinula to be identified as intermediate host for A. costaricencis in southern Brazil.

Veronicellid slugs are considered the most important intermediate hosts of Angiostrongylus costaricensis, an intra-arterial nematode of rodents. Studies undertaken in three localities in southern Brazil led to identification of molluscs other than veronicellid slugs as hosts of A. costaricensis: Limax maximus, Limax flavus and Bradybaena similaris. These data indicate a low host specificity of larval stages of A. costaricensis, as it has been reported to other congeneric species.

The vertical distribution and the segregation by size of the yellow clam Mesodesma mactroides Deshayes, 1854 were investigated in the intertidal zone and its limits with the lower and upper shores at exposed sandy beaches of Rio Grande do Sul state, Brazil. The gathering was made throughout 12 months; from the Pinhal beach towards the south of the State, in six 15 km equidistant transects, determined through random selection. In these transects, the calculation of 30 consecutive waves was made in order to determine its average amplitude point (P0), from which two points were marked towards the lower shore (P-1 and P-2) and three towards the upper shore (P1, P2 and P3). A 30 by 50 cm cylinder was buried down to the depth of 40 cm, the material was separated with a 0.25 cm mesh and the specimens were quantified and measured in length. The yellow clam presented segregation by size, especially between recruit and adult individuals, with recruits occupying preferably the zones above P0 and adults from this point towards the sea. The young specimens are distributed through all zones, mixed with adult and recruit specimens, which dismisses the hypothesis of segregation by size in function of competition for space and food, once the burying depth is directly proportional to their length. However, the segregation between recruits and adults might be related to the filtering mechanism of the adults, which could ingest the larva, as well as the fact that the recruits, being small and light, are easily transported to the regions above P0. Seasonal migration was observed for adult individuals during winter and spring, probably associated to the reproduction period of the species, being that the peak of recruitment was greater in the end of the winter and the beginning of spring.