The use of antifouling paints containing the biocide compound tributyltin (TBT) has been shown as an inductor of imposex in neogastropods mollusks. Imposex is characterized by the development of male features in females, mainly the appearance of a no functional vas deferens and penis. Samples of Thais rustica were collected in eight sites in the metropolitan area of Natal city, Rio Grande do Norte state, northeast Brazil, and examined for occurrence of imposex, which was found in many females. The higher imposex levels were presented by samples from sites near city harbor.
A utilização de tintas antiincrustrantes contendo o composto biocida tributilestanho (TBT) tem induzido moluscos neogastrópodes ao imposex. O imposex é caracterizado pelo surgimento de caracteres sexuais masculinos, sobretudo, pênis e vaso deferente não funcionais em fêmeas desses moluscos. Foram coletadas amostras de Thais rústica em oito estações ao longo da costa da cidade de Natal no Rio Grande do Norte. Esses animais foram analisados quanto a presença e o grau de imposex que apresentavam. Os níveis mais elevados de imposex foram observados na estação mais próxima ao porto

Qualitative samples of ‘opisthobranchs’ were collected from different beaches and estuaries in Ceará State, North-east Brazil. Further species distributions from the literature were used to infer patterns of distribution and to analyse faunal similarity among Atlantic biogeographic areas, Brazilian zones and the Ceará State. A total of 35 new records are reported for the Ceará State, including 19 new records from the North-east Brazilian Shelf (NBS), 12 new from the Brazilian Province and two new records from the South Atlantic. More than half of the species in this area are common between the Caribbean and Brazilian provinces, which demonstrates their capacity for crossing the Amazon–Orinoco barrier. The high percentage of occurrence in the NBS and the South Brazilian Bight, when compared to neighbouring zones, may be attributed to the poor knowledge of the Brazilian ‘opisthobranch’ fauna.

Imposex is characterized by the development of masculine sexual organs in neogastropod females

Teeth and otoliths are metabolically inert structures that preserve a chronology of chemical variations that may be related to the environmental histories experienced by each organism. Because of the natural decrease of barium (Ba) and increase of strontium (Sr) bioavailability in water with increasing salinity, these elements may be especially useful to track habitat use in aquatic organisms. Therefore, we tested whether the Ba/Ca and Sr/Ca ratios in the teeth of dolphins represent a salinity gradient. The main aim was to determine whether these elements can be used as a natural tag for different aquatic environments. Teeth from 2 freshwater dolphins (Inia geoffrensis and Sotalia fluviatilis) and 2 marine species (S. guianensis and Pontoporia blainvillei) from Brazil and Uruguay were analyzed using a Laser Ablation Inductively Coupled Plasma-Mass Spectrometer. Intensity ratios of 138 Ba/ 43 Ca and 86 Sr/ 43 Ca were measured along a line that covered all growth increments in the dentin from the second year of life onwards. Teeth from the freshwater species had mean Ba/Ca values tenfold higher than marine dolphins, confirming the inverse relationship between salinity (and thus ambient Ba/Ca) and elemental ratios in teeth. Furthermore, Ba/Ca ratios could also differentiate dolphins from lower-salinity estuarine areas from those in areas with minimal freshwater discharge. No significant differences were found for Sr/Ca values. Results presented encouraging indications for the application of this technique as a potential new tool for studying habitat use in aquatic mammals.

Imposex is characterized by the development of male characteristics, such as the penis and vas deferens, in female prosobranch gastropods, caused by organotin compounds contamination. In Brazil, imposex was observed in the muricids Stramonita haemastoma and Stramonita rustica and in the olivid Olivancillaria vesica. During the low tide, 54 adult individuals of Leucozonia nassa were manually collected in February 2004 at Ilha do Japonês tidal flat, Cabo Frio County, Rio de Janeiro State, south-east Brazil. About 98.15% of females presented imposex (N ¼ 30). Their penises were smaller than male ones. Only 1 imposexed female presented a biphallia problem, showing 2 flattened penises with a small scourge in the edge. This is the first record of biphallia in an imposexed female of fasciolarid Leucozonia nassa.a first record of biphallia in imposexed leucozonia nassa

We analyzed qualitatively the malacofauna found in the tidal zones of Banco dos Cajuais and Ilha Grande estuarine complex, both in Ceará State, northeastern Brazil. Qualitative data on the malacofauna from Banco dos Cajuais and the Ilha Grande estuarine complex were obtained by systematic sampling in 2008 and 2009 during field activities for the “Migratory Shorebirds Conservation and Shrimp Farming in Northeast Brazil” project. Twenty-two species of mollusks (13 bivalves and 9 gastropods) were found in Banco dos Cajuais, and 25 species (18 bivalves and 7 gastropods) were found in the Ilha Grande estuarine complex. Four species, Lucina muricata (Spengler, 1798), Tagelus divisus (Lightfoot, 1786), Crassinella martinicensis (d’Orbigny, 1853), and Periploma ovata Kuroda and Horikoshi, 1958 were recorded from Ceará for the first time.

A família Fasciolariidae é formada por espécies carnívoras que usualmente predam outros gastrópodes e bivalves. Geralmente utilizam como estratégia de predação, o lascamento de concha, meio pelo qual o predador pode alcançar as partes moles da presa. Os objetivos desse trabalho foram determinar as possíveis presas de Aurantilaria aurantiaca da Praia do Pacheco (Caucaia-CE-Brasil) e a sua preferência alimentar em condições de laboratório. As presas observadas foram os gastrópodes Pisania pusio, Tegula viridula e Stramonita brasiliensis. O experimento de preferência de presa foi executado acondicionando um predador em um aquário de 5 litros com um indivíduo de cada presa, sendo observado durante 60 dias (replicado 10 vezes). Para a determinação do tempo de manipulação da presa, um predador foi acondicionado em uma caixa plástica mergulhada em um aquário de 80 litros juntamente com uma espécie de presa, sendo anotado o tempo de predação por duas 2 horas, durante 30 dias (replicado 10 vezes para cada espécie de presa). Aurantilaria aurantiaca mostrou preferência por Stramonita brasiliensis, o qual teve o mais baixo tempo de manipulação da presa. Pisania pusio e Tegula viridula não apresentaram resultados estatisticamente significativos (p = 0.7235 e 0.2499, respectivamente). O comportamento predatório mostrou 2 estratégias: penetração direta da probóscide e sufocamento. Não houve registro de lascamento de concha. Aurantilaria aurantiaca apresentou-se como um predador generalista, onde a variação de tempo de manipulação da presa mostrou que o predador passou por um processo de aprendizagem. ABSTRACTFasciolariid species are predators that prey on other gastropods and bivalves. They usually break prey shell to reach its soft parts. In this study, prey species that Aurantilaria aurantiaca consumes at Pacheco Beach (Ceará State, Northeast Brazil) and its prey preference in laboratory conditions were determined. Prey species observed were Pisania pusio, Tegula viridula and Stramonita brasiliensis. Prey preference experiment was performed placing one individual of Aurantilaria aurantiaca and one individual of each prey species in a 5 liters tank. It lasted 60 days and was replicated 10 times. Handling time of predation on each prey was measured by placing one predator with one prey into separate plastic containers in an 80 liters tank. Observations were made every 2 hours over a 30-day period. Aurantilaria aurantiaca showed preference for Stramonita brasiliensis, which presented the shortest handling time. Pisania pusio and Tegula viridula didn't show statistical significant results (p = 0.7235 e 0.2499 respectively). Aurantilaria aurantiaca presented 2 main predatory strategies: direct prey shell penetration and asphyxiating process. No damaged prey shells were observed. The predator showed a generalist predatory behavior. Prey handling time variations demonstrated that Aurantilaria aurantiaca predation act involved a training process.

SUMMARY: Spawn and larval development stages of Pleuroploca aurantiaca from northeast Brazil are described. The reproductive period lasted from August to December, with a peak in November. Spawn masses were composed of 29 ± 3 vase-shaped capsules which measured 9 ± 1 mm (n = 30) in length and 4.5 ± 0.5 mm (n = 30) in width. The exit plug was located on the apical area and measured 2.5 ± 0.5 mm (n = 30) in diameter. Each capsule had 353 ± 59 (n = 10) eggs that measured 240 ± 1 µm (n = 15) in diameter. On the tenth day, the intracapsular veliger stage was observed. The intracapsular pediveliger stage was observed on the twenty first day, when the individuals had a functional foot and a reduced velum. Hatching occurred on the thirtieth day, when the early juvenile measured 3 to 5 mm in length and there was no remaining velum. Only 1% of the eggs developed to the hatching stage. The rest were nurse eggs used by embryos as a food resource. Pleuroploca aurantiaca has an intracapsular metamorphosis development type.Keywords: reproduction, development, Mollusca, Fasciolariidae, Pleuroploca, Pleuroploca aurantiaca. RESUMEN: PUESTA Y DESARROLLO LARVARIO DE PLEUROPLOCA AURANTIACA (LAMARCK, 1816) (GASTROPODA: FASCIOLARII-DAE) DEL NE DE BRASIL. -Se describe la puesta y los estadios de desarrollo larvario de Pleuroploca aurantiaca del NE de Brasil. El período reproductivo se extiende desde agosto a diciembre, con un pico en noviembre. Las masas de puesta están formadas por 29 ± 3 cápsulas en forma de vaso de 9 ± 1 mm de longitud (n = 30) y 4.5 ± 0.5 mm (n = 30) de anchura. El orificio de salida está localizado en el área apical y mide 2. 5 ± 0.5 mm (n = 30) de diámetro. Cada cápsula tiene 353 ± 59 (n = 10) huevos de 240 ± 1 ?m (n = 15) de diámetro. El estadio veliger intracapsular fue observado al décimo día. El estadio pediveliger intracapsular fue observado al vigésimo primer día, cuando los individuos ya tienen un pie funcional y un velum reducido. La eclosión tuvo lugar el día 30 y los primeros juveniles midieron entre 3 y 5 mm de longitud. No se observaron restos de velo. Sólo un 1% del total de huevos se desarrollaron hasta el estadio de eclosión. El resto fueron usados por los embriones como fuente de alimento. P. aurantiaca presenta un tipo de desarrollo metamórfico intracapsular.