Carlos Augusto Oliveira de Meirelles

Thais (Stramonita) rustica (Lamarck, 1822) (Mollusca: Gastropoda: Thaididae), a potential bioindicator of contamination by organotin northeast Brazil

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.

Imposex in endemic volutid from Northeast Brazil (Mollusca: Gastropoda)

Imposex is characterized by the development of masc uline sexual organs in neogastropod females. Almost 120 mollusk species are known to present imposex when eto organic tin compounds as tributyltin (TBT ) and triphenyltin (TPT). These compounds are used as bio cide agents in antifouling paints to prevent the in crustations on boats. Five gastropod species are known to present imposex in Brazil: Stramonita haemastoma, Stramonit a rustica, Leucozonia nassa, Cymathium parthenopeum and Olivan cillaria vesica. This paper reports the first recor d of imposex observed in the endemic gastropod Voluta eb raea from Pacheco Beach, Northeast Brazil. Animals presenting imposex had regular female reproductive organs (capsule gland, oviduct and sperm-ingesting gland) and an abnormal penis. As imposex occurs in mollusks ex posed to organotin compounds typically found at har bors, marinas, shipyards and areas with high shipping act ivities, probably contamination of Pacheco Beach is a consequence of a shipyard activity located in the n earest areas.

Mollusks from two estuarine areas in Ceará state, northeastern Brazil, with new state records for four species

We analyzed qualitatively the malacofauna found in the tidal zones of Banco dos Cajuais and Ilha Grande estuarine complex, both in Ceara 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 Ceara for the first time.

Mollusks Found Inside Octopus (Mollusca, Cephalopoda) Pots in the State of Ceara, Northeast Brazil~!2008-09-15~!2008-12-01~!2009-01-06~!

The fishery of octopus in the State of Ceara is being carried out in the coast of Fortaleza, Redonda Beach (Icapui) and Itarema where 2 species can be found, Octopus insularis and O. vulgaris. The objective of this study was to investigate which prey species of mollusks were found inside the pots used in the octopus fishery. Unbaited octopus pots were set in Redonda Beach at 30 meters depth, in Fortaleza at 27 meters depth, and in Itarema at 30 meters depth. The species found inside the octopus pots that were consumed by Octopus vulgaris and O. insularis were mainly gastropods and bivalves. It was found 32 species of mollusks, being 17 of gastropods and 15 of bivalves. Redonda Beach presented the higher number of mollusk species in the octopus pots, with 85% of the total. The most preyed gastropod species was Aliger costatus (35.6%) and the most preyed bivalve species was Anadara notabilis (54.5%). Among the gastropods, 54% had a bore hole, the majority on the spire in the ventral side of the shell. This location is probably due to the presence of the columelar muscle, where it can inject the poison. Only 4.3 % of the bivalves found inside the octopus pots presented bore holes. Empty shells were censured in the field to indicate the magnitude of octopus predation relative to other sources of mortality and the percentage of empty shells with octopus drill holes ranged from 14% to 69%.