The genus Mytilus comprises a large number of bivalve mollusk species distributed throughout the world and many of these species are considered invasive. In South America, many introductions of species of this genus have already taken place, including reports of hybridization between them. Now, the occurrence of the Mediterranean mussel Mytilus galloprovincialis is reported for the first time from the Brazilian coast. Several specimens of this mytilid were found in a shellfish growing areas in Florianópolis and Palhoça, Santa Catarina State, Brazil. Morphological analysis of the shells and molecular analysis through sequencing of the cytochrome oxidase subunit 1 (COI) confirmed the taxonomic identification. The species is known for its great invasive potential and can become a major environmental problem for seafood business and coastal communities, as it can compete and even hybridize with local species.

Mirinaba cadeadensis (Morretes, 1952), a strophocheilid land snail, is known from Morro Cadeado, Estrada da Graciosa and Pico Marumbi, all located in the Atlantic Rainforest biome along the coast of Paraná state, Brazil. Based on material from the collection of the Museu de História Natural Capão da Imbuia (Curitiba, Brazil) and newly collected specimens, we report the occurrence of this species in 11 new localities in this region.

<p style="text-align: justify;">A Ilha do Farol é uma ilha continental, no estado do Paraná, sul do Brasil. Devido à sua posição em relação ao continente, três ambientes distintos são observados nela: área de costão rochoso exposto ao mar aberto (A); área estuarina (B); área de praia arenosa (C). Considerando que as ilhas continentais são excelentes modelos de estudo que reproduzem as condições ambientais da zona costeira em menor escala, o estudo teve como objetivo levantar e pesquisar a malacofauna marinha na Ilha do Farol e comparar sua diversidade e composição. O método de amostragem foi baseado em coletas mensais nos três ambientes da ilha durante dois anos (2011-2012). O levantamento encontrou 91 espécies: 47 Gastropoda, 41 Bivalvia e três Scaphopoda. A maior riqueza e abundância de espécies prevaleceu no ambiente A. A maior equidade foi observada em B e o maior domínio em C. Houve predominância de Gastropoda e Bivalvia em A, enquanto a frequência de Scaphopoda não variou entre os ambientes. A composição de espécies das três classes variou entre as três áreas. A variação da diversidade e composição das espécies nos três ambientes podem estar relacionados com as características naturais de cada ambiente da ilha, como salinidade e ação de ondas.</p><p style="text-align: justify;"><strong>Palavras chave</strong>: Abundância, conservação, equitabililidade, levantamento, riqueza, Mollusca.</p><p style="text-align: justify;"><strong>Abstract</strong>: Farol Island is a continental island in the state of Paraná, southern Brazil. Due to its position in relation to the continent, three distinct environmental areas are observed: rocky shore area with open exposure to the sea (A) estuarine area (B); sandy beach area (C). Considering that the continental islands are excellent study models that reproduce the environmental conditions of the coastal zone in a smaller scale, the study aimed at surveying and researching the marine malacofauna on the Farol Island and comparing the diversity and shellfish composition. The sampling method was based on a monthly collection in three locations for two years (2011-2012). The survey found 91 species: 47 Gastropoda, 41 Bivalvia and three Scaphopoda. The highest abundance and species richness prevailed in environmental area A. The greatest equitability was observed in B and the highest dominance in C. There was a predominance of Gastropoda and Bivalvia in A, while the frequency of Scaphopoda did not vary among environments. The species composition of the three classes varied among the three areas. The variation of diversity and species composition in the three environments may be related to the natural characteristics of each side of the island, as salinity and wave action.</p><p style="text-align: justify;"><strong>Key words</strong>: Abundance, conservation, equitability, survey, richness, Mollusca.</p>

The new bulimulid species, Drymaeus currais sp. nov., is described based on shell and anatomical features. It is endemic of Guapirá Island, belonging to the Currais Archipelago, a small protected area off Paraná coast. The species is thus, based at least on endemicity, endangered. It has as closest species D. castilhensis, another endemic species of Castilho Island, ~70 km northwards. Its main exclusivities are a banded shell (except for periumbilical area); a ureter ~1/3 opened (furrow); an external anus; a slightly different buccal and intestinal arrangement; a penis lacking internal chambers; a small receptacle with a genital appendix. Zoobank Register: urn:lsid:zoobank.org:pub:25B25A8B-CED0-4284-A799-5383998BE481.

Exotic species are those that occur in an area beyond their natural limit and they are considered invasive when they cause harm to the economy, environment, or human health. In coastal environments, ballast water and inlays on the hull and other parts of vessels are the main ways of introducing invasive aquatic alien species. Nassarius foveolatus (Dunker, 1847) is native from the Central and East Indian Ocean to the East China Sea. The first specimens (empty shells) of N. foveolatus were collected manually on November 11, 2017 on the Rocio footbridge, located in the Paranaguá Estuarine Complex, on the coast of the State of Paraná, southern Brazil. Posteriorly, live specimens were collected in other localities of this bay. It is already possible to infer that the specimens of N. foveolatus occur together with the native specimens of N. vibex (Say, 1822), having the same niche. As previously only N. vibex existed in that place, at least a displacement of this native species has been occurred. However, certainly future ecological studies may confirm this displacement and additional consequences to the local ecosystem, as nassariids can be predators and scavengers. Control procedures should be also greatly implemented.