Nanoemulsion containing essential oil from Xylopia ochrantha Mart. produces molluscicidal effects against different species of Biomphalaria (Schistosoma hosts)

BACKGROUND This work describes a chemical study of the essential oil from leaves of Xylopia ochrantha, an endemic Annonaceae species from Brazil, and its activity against Biomphalaria species. Considering its poor solubility in aqueous medium, the essential oil was nanoemulsified to evaluate its action on controlling some mollusc species of genus Biomphalaria, snail hosts of Schistosoma mansoni that causes schistosomiasis, which mainly affects tropical and subtropical countries. OBJECTIVES The main aims of this work were to analyse the chemical composition of essential oil from X. ochrantha, and to evaluate the effect of its nanoemulsion on molluscs of genus Biomphalaria and their oviposition. METHODS Chemical analysis was performed by gas chromatography coupled to mass spectrometry. Nanoemulsions were prepared by a low energy method and characterised by particle size and polydispersity index. Biological assays evaluating the mortality of adult species of B. glabrata, B. straminea and B. tenagophila and their ovipositions upon contact with the most stable nanoemulsion during 24 and 48 h were performed. FINDINGS Chemical analysis by mass spectrometry revealed the majority presence of bicyclogermacrene and germacrene D in the essential oil. The formulation with a hydrophilic-lipophilic balance (HLB) of 9.26 was the most suitable for the oil delivery system. This nanoemulsion caused the mortality in B. tenagophila, B. straminea and B. glabarata of different sizes at levels ranging from 50 to 100% in 48 h. Additionally, the formulation could inhibit the development of deposited eggs. CONCLUSION Thus, these results suggest the use of nanoemulsified essential oil from X. ochrantha as a possible alternative in controlling some Biomphalaria species involved in the schistosomiasis cycle.

A new amide compound from Onchidium verruculatum / 中草药

Objective: To study the chemical composition of the marine characteristic resource, Onchidium verruculatum from Hainan Island. Methods: Compound was separated and purified by silica gel and semi-preparative HPLC, detected by TLC, and identified by NMR and MS data. Compound 1 was evaluated for cytotoxic activity against four kinds of human tumor cell lines HepG-2, BEL-7042, A549, and MCF-7. Results: A new amide compound, N-(2-hydroxy-4-methoxy-5-methylphenyl)formamide (1), was isolated from mucus and muscle tissue of O. verruculatum. The results showed that compound 1 has moderate toxic activity against A549 and BEL-7402 cell lines, with IC50 value of 11.5 μg/mL and 19.4 μg/mL. Conclusion: Compound 1 is a new amide compound named onchumamide with moderate toxic activity on human tumor cells.

Methanolic extract of Euchelus asper exhibits in-ovo anti-angiogenic and in vitro anti-proliferative activities

BACKGROUND: The marine environment is a rich source of bioactive natural products. Many of the marine bioactive compounds have been derived successfully from molluscs. Euchelus asper is a marine mollusc which is commonly found in the intertidal rocky regions of the Mumbai coast. The present study was focused on evaluating the anti-angiogenic and anti- proliferative activities of methanolic extract of Euchelus asper (EAME). METHODS: The anti-angiogenic activity of EAME (50-800 µg/mL) was assessed by chick chorio-allantoic membrane (CAM) model wherein multiple parameters in the CAM blood vessels were analysed through morphometric and histo-logical investigations. In vitro testing of EAME (5-20 µg/mL) included its cytotoxicity against three different cancer cell lines, its effect on cell proliferation by wound healing assay as well as their relevant molecular mechanisms. Statistical analysis was carried out by two-tailed student's t test for two unpaired groups. RESULTS: Analysis of CAM revealed that the extract is effective in reducing the branching points of the 1st order blood vessels or capillaries of CAM. Histological analysis of CAM showed significant decrease in capillary plexus and compartmentalization along with increase in mesodermal blood vessels, thus establishing its anti-angiogenicity. Further, EAME exhibited moderate but significant cytotoxicity against A549 non-small cell lung carcinoma cell line. We also demonstrated that the cytotoxicity of EAME in A549 was associated with its apoptotic activity by subG1 phase arrest. Lastly, EAME significantly reduced A549 proliferation by reducing the expression of Matrix metalloproteinase-2 (MMP-2) and Matrix metalloproteinase-9 (MMP-9). CONCLUSION: Overall, our study suggested that EAME has potential to inhibit tumour angiogenic and proliferative activity and may be a potential source for development of new anti-cancer pharmaceuticals.

O mexilhão Perna perna no Brasil: nativo ou exótico? / The brown mussel Perna perna in Brazil: native or exotic?

A mitilicultura no Brasil se baseia no mexilhão Perna perna (Linnaeus, 1758), que é encontrado em todo o litoral brasileiro, sendo especialmente abundante do Espírito Santo a Santa Catarina. Nos últimos anos, foi lançada a hipótese de que P. perna seja uma espécie exótica no litoral brasileiro. A hipótese se baseia na análise da malacofauna presente em sítios arqueológicos. Todas as contestações levantadas não remetem à uma conclusão, pois precisam de estudos específicos, com metodologias claras, aliando arqueologia, ecologia e biologia molecular. O objetivo deste trabalho foi estudar a condição de nativo ou exótico do mexilhão Perna perna no Brasil, a partir de levantamento dos resultados em sítios arqueológicos, de técnicas moleculares e de datação de conchas com C14. A datação indicou que as amostras de Perna perna do sítio arqueológico Rio do Meio/Jurerê, Florianópolis/SC, têm idade de 720±30 e 780±30 anos. O cálculo do tempo de divergência indicou que a separação das populações brasileiras e africanas ocorreu por volta de 200 mil anos. Os resultados apontam a presença da espécie no território brasileiro muito antes do descobrimento do Brasil pelos portugueses no ano de 1500, indicando que P. perna é de fato uma espécie nativa.

Mussel farming in Brazil is based on brown mussel Perna perna (Linnaeus, 1758), which is found throughout the Brazilian coast, especially abundant from Espírito Santo to Santa Catarina coast. In recent years it was suggested that Perna perna is an exotic species for the Brazilian coast. The hypothesis is based on the analysis of the zooarchaeology studies in archaeological sites in Brazil. All objections raised do not offer a conclusion, because they need specific studies with clear methodology, combining archeology, ecology and molecular biology. The aim of this work was to study the condition of the brown mussel Perna perna in Brazil if native or exotic, from survey results in archaeological sites, molecular techniques and dating of shells with C14. The dating indicated that the shells were 720±30 and 780±30 years, respectively. The calculation of divergence time indicated that the separation of the African and Brazilian mussel populations occurred around 200 thousand years ago. The results indicate the presence of the P. perna species in Brazilian territory long before the discovery of Brazil by the Portuguese in 1500, indicating that P. perna is actually a native species of Brazil.

Traditional utilization and biochemical composition of six mollusc shells in Nigeria / Utilización tradicional y composición bioquímica de seis conchas de moluscos en Nigeria

The shells of molluscs protect them from physical damage, predators and dehydration. We studied various local uses of shells and their biochemical properties in Abeokuta, Nigeria. A standard structured questionnaire about use was applied to 100 snail and herb sellers and shells from 120 adult individuals of Archachatina marginata, Achatina achatina, Achatina fulica, Littorina littorea, Meretrix lusoria and Merceneria mercenaria were evaluated for their mineral components (Ca2+, Fe2+, Mg2+, Na+, Zn+, P+, K+) and proximate composition (crude protein, ash, fibre, crude fat and carbohydrate) using standard methods. Properties against fungi and bacteria isolates were also tested. These shells are used for bleaching, brushing, abrasion and others. The weight of the shells varied from 0.5g (L. littorea) to 25.00g (A. marginata) and thickness from 0.46mm in M .lusoria to 5.35mm in M. mercenaria. We found no inhibitory effect against fungi and bacterial isolates. The molluscs are high in carbohydrates (83.54-92.76g/100g) and low in protein (0.16-0.38g/100g). The fat content ranged between 0.42g/100g and 0.82g/100g, and ash between 2.14g/100g and 9.45g/100g. Ca2+ was the most abundant (10.25-96.35mg/g) while K+ was the least abundant (0.3-0.7mg/g) (p<0.05). Active ingredients of these shells can be used in the feed and construction industries.

Las conchas protegen a los moluscos del daño físico, los depredadores y la deshidratación. En este trabajo se estudiaron los diversos usos locales de las conchas y sus propiedades bioquímicas en Abeokuta, Nigeria. Se utilizó un cuestionario estructurado estándar sobre los usos de las conchas, aplicado a 100 vendedores de caracoles y hierbas, conchas de 120 individuos adultos de Archachatina marginata, Achatina achatina, Achatina fulica, Littorina littorea, Meretrix lusoria y Merceneria mercenaria fueron evaluados para la extracción de los compuestos minerales (Ca2+, Fe2+, Mg2+, Na+, Zn+, P+, K+) y la composición proximal (proteína cruda, materia seca, fibra, contenido graso y carbohidratos) usando métodos estándar. También se analizaron las propiedades de aislamientos contra hongos y bacterias. Las conchas se utilizan para el blanqueamiento, cepillado, abrasión y otros. El peso de las conchas varió de 0.5g (L. littorea) a 25.00g (A. marginata) y el espesor de 0.46mm en M. lusoria a 5.35mm en M. mercenaria. No se encontraron efectos inhibidores de los aislamientos contra hongos y bacterias. Los moluscos resultaron ricos en carbohidratos (83.54-92.76g/100g) y bajos en proteínas (0.16-0.38g/100g). El contenido graso osciló entre 0.42g/100g y 0.82g/100g y la materia seca entre 2.14g/100g y 9.45g/100g. Ca2+ fue el más abundante (10.25-96.35mg/g), mientras que K+ el menos abundante (0.3-0.7mg/g) (p<0.05). Los ingredientes activos de estas conchas se pueden utilizar en la industria alimentaria y de la construcción.

Molluscs associated with the macroalgae of the genus Gracilaria (Rhodophyta): importance of algal fronds as microhabitat in a hypersaline mangrove in Northeastern Brazil

The fronds of marine macroalgae play an important role in coastal ecosystems because the algae banks are utilized as a microhabitat by different taxa, including molluscs, one of the most abundant and diverse animals of marine ecosystems. In this study, we characterized the malacofauna associated with the macroalgae Gracilaria domingensis (Kützing) Sonder ex Dickie 1874 and Gracilaria cuneata Areschoug 1854 of a hypersaline mangrove on the northern coast of the state of Rio Grande do Norte, Northeastern Brazil. The first alga dominates in the rainy season and it is substituted by second one in the dry period. A total of 1,490 molluscs were surveyed, representing 56 species in 29 families: 1,081 were associated with G. domingensis and 409 with G. cuneata, the latter showing the greater diversity (H=1.25). Columbellidae, Neritidae, Pyramidellidae and Cerithiidae were among the most representative families in the number of species and individuals. The micromolluscs were dominant in the algal microhabitat, constituting 74.63% of the malacofauna recorded. The columbellid Parvanachis obesa(C. B. Adams, 1845) was the dominant species followed by the neritid Neritina virginea (Linnaeus, 1758) in both algae. In spite of the annual alternated succession of the algae species, at least 15 mollusc species are common for these algae. Furthermore, juveniles of P. obesa were recorded in both seasons, indicating a continuous reproduction. Possible reasons for difference in abundance, diversity and dominance of molluscs living on these algae are discussed. Both species of substrate-algae represent an important microhabitat for refuge, feeding and the reproduction of small-sized mollusc species during rainy and dry seasons.

As frondes de macroalgas marinhas exercem um importante papel nos ecossistemas costeiros, tendo em vista que os bancos de algas são utilizados como microhabitat por diferentes táxons, incluindo os moluscos, que estão entre os mais abundantes e diversos animais dos ecossistemas marinhos. Neste estudo, caracterizou-se a malacofauna associada às macroalgas Gracilaria domingensis (Kützing) Sonder ex Dickie 1874 e Gracilaria cuneata Areschoug 1854 de um manguezal hipersalino da costa norte do estado do Rio Grande do Norte, Nordeste do Brasil. A primeira alga domina no período chuvoso e é substituída pela segunda no período seco. Foram inventariados 1.490 moluscos, representando 56 espécies em 29 famílias: 1.081 estavam associados a G. domingensis e 409 a G. cuneata, esta última apresentando maior diversidade (H=1,25). Columbellidae, Neritidae, Pyramidellidae e Cerithiidae estiveram entre as famílias mais representativas em número de espécies e indivíduos. Os micromoluscos foram dominantes no microhabitat algal, constituindo 74,63% da malacofauna registrada. O columbelídeo Parvanachis obesa (C. B. Adams, 1845) foi a espécie dominante, seguida pelo neritídeo Neritina virginea (Linnaeus, 1758) em ambas as algas. Apesar da sucessão alternada anual das espécies de algas, pelo menos 15 espécies de moluscos são comuns a estas algas. Além disso, os jovens de P. obesa foram registrados em ambas as estações, indicando uma reprodução contínua. São discutidas possíveis razões para a diferença na abundância, diversidade e dominância dos moluscos habitantes destas algas. Ambas as espécies de alga-substrato representam um importante microhabitat para refúgio, alimentação e reprodução para pequenas espécies de moluscos durante as estações chuvosa e seca.

Molluscs associated with the macroalgae of the genus Gracilaria (Rhodophyta): importance of algal fronds as microhabitat in a hypersaline mangrove in Northeastern Brazil / Moluscos associados a macroalgas do gênero Gracilaria (Rhodophyta): importância das frondes algais como microhabitat em um manguezal hipersalino no Nordeste do Brasil

The fronds of marine macroalgae play an important role in coastal ecosystems because the algae banks are utilized as a microhabitat by different taxa, including molluscs, one of the most abundant and diverse animals of marine ecosystems. In this study, we characterized the malacofauna associated with the macroalgae Gracilaria domingensis (Kützing) Sonder ex Dickie 1874 and Gracilaria cuneata Areschoug 1854 of a hypersaline mangrove on the northern coast of the state of Rio Grande do Norte, Northeastern Brazil. The first alga dominates in the rainy season and it is substituted by second one in the dry period. A total of 1,490 molluscs were surveyed, representing 56 species in 29 families: 1,081 were associated with G. domingensis and 409 with G. cuneata, the latter showing the greater diversity (H′=1.25). Columbellidae, Neritidae, Pyramidellidae and Cerithiidae were among the most representative families in the number of species and individuals. The micromolluscs were dominant in the algal microhabitat, constituting 74.63% of the malacofauna recorded. The columbellid Parvanachis obesa (C. B. Adams, 1845) was the dominant species followed by the neritid Neritina virginea (Linnaeus, 1758) in both algae. In spite of the annual alternated succession of the algae species, at least 15 mollusc species are common for these algae. Furthermore, juveniles of P. obesa were recorded in both seasons, indicating a continuous reproduction. Possible reasons for difference in abundance, diversity and dominance of molluscs living on these algae are discussed. Both species of substrate-algae represent an important microhabitat for refuge, feeding and the reproduction of small-sized mollusc species during rainy and dry seasons.

As frondes de macroalgas marinhas exercem um importante papel nos ecossistemas costeiros, tendo em vista que os bancos de algas são utilizados como microhabitat por diferentes táxons, incluindo os moluscos, que estão entre os mais abundantes e diversos animais dos ecossistemas marinhos. Neste estudo, caracterizou-se a malacofauna associada às macroalgas Gracilaria domingensis (Kützing) Sonder ex Dickie 1874 e Gracilaria cuneata Areschoug 1854 de um manguezal hipersalino da costa norte do estado do Rio Grande do Norte, Nordeste do Brasil. A primeira alga domina no período chuvoso e é substituída pela segunda no período seco. Foram inventariados 1.490 moluscos, representando 56 espécies em 29 famílias: 1.081 estavam associados a G. domingensis e 409 a G. cuneata, esta última apresentando maior diversidade (H′=1,25). Columbellidae, Neritidae, Pyramidellidae e Cerithiidae estiveram entre as famílias mais representativas em número de espécies e indivíduos. Os micromoluscos foram dominantes no microhabitat algal, constituindo 74,63% da malacofauna registrada. O columbelídeo Parvanachis obesa (C. B. Adams, 1845) foi a espécie dominante, seguida pelo neritídeo Neritina virginea (Linnaeus, 1758) em ambas as algas. Apesar da sucessão alternada anual das espécies de algas, pelo menos 15 espécies de moluscos são comuns a estas algas. Além disso, os jovens de P. obesa foram registrados em ambas as estações, indicando uma reprodução contínua. São discutidas possíveis razões para a diferença na abundância, diversidade e dominância dos moluscos habitantes destas algas. Ambas as espécies de alga-substrato representam um importante microhabitat para refúgio, alimentação e reprodução para pequenas espécies de moluscos durante as estações chuvosa e seca.

Distribution of univalvia molluscs in area with natural decline of Oncomela-nia hupensis snails in Eastern Dongting Lake area / 中国血吸虫病防治杂志

Objective To understand the distribution of univalvia molluscs in Eastern Dongting lake area where the Oncome-lania hupensis is extinct,so as to explore the causes of extinction and to provide the evidence for formulating schistosomiasis con-trol strategy. Methods The univalvia molluscs of the Qianliang Lake district,Jianxin District and Junshan Park were investigat-ed in August of 2013. All the collected snails were classified and identified. The data were analyzed by using the method of Shapiro-Wilk normality test and non-parametric test. The ecological biodiversity differences from each district were compared by the biodi-versity indexes. Results The univalvia molluscs collected were from 6 species in 3 families in Gastropoda class,namely Oncome-lania hupensis Gredler in Pomatiopsidae family,Parafossarulus striatulus,Alocinma longicornis,Parafossarulus sinensis,Bithynia fuchsisana in Bithyniidae family,and one genus provisionally named Radix in Lymaneidae family. In Junshan Park ,a total of 4 553 snails were collected,among which 1 264 were Oncomelania snails. In Jianxin District,336 univalvia molluscs were collect-ed,and no Oncomelania snails were found. In Qianliang Lake district,there were only 7 Alocinma longicornis snails,2 Parafossa-rulus sinensis snails and 1 Parafossarulus striatulus snail collected. There were significant differences among the distributions of the samples from the three districts(χ2=166.225,P<0.01).The Simpson’s diversity indexes in Qianliang Lake area,Jianxin Dis- trict and Junshan Park were 0.402 8,0.718 6 and 0.678 8,respectively,and the Shannon-Wiener indexes of the 3 areas were 0.721 5,1.431 3 and 1.199 9,respectively. Conclusions With the extinction of Oncomelania snails,the species and quanti-ties of other snails become rare in Qianliang Lake area. Whether their causes are relevant is worth further studying.

A new labdane diterpene from the limpet Trimusculus peruvianus / Un nuevo diterpeno labdano aislado del molusco Trimusculus peruvianus

The family Trimusculidae produces labdane diterpenes, which differ in the degree and type of esterification with acetoxy and isovaleroyl ester predominantly. Here we describe the isolation from the marine pulmonate Trimusculus peruvianus, collected on intertidal rocks of Chilean coasts, of a new diterpene closely related to the above mentioned characteristics. It structure was determined by spectroscopic data. The compounds were subjected to toxicity tests using nauplii and cysts of Artemia salina. The known compounds isolated in this study have shown an ability to inhibit egg hatch of A. salina.

La familia Trimusculidae produce diterpenos tipo labdano, que difieren en el grado y tipo de esterificación con esteres acetato e isovalérico predominantemente. En este trabajo describimos el aislamiento de un nuevo diterpeno con las características ya mencionadas y de otros ya conocidos desde el molusco marino pulmonado Trimusculus peruvianus, recolectado en la zona intermareal del litoral chileno. Su estructura fue determinada a través de métodos espectroscopicos. Los compuestos fueron sometidos a ensayos de toxicidad y eclosión de los huevos de Artemia salina.

Parasites of the mangrove mussel Mytella guyanensis (Bivalvia: Mytilidae) in Camamu Bay, Bahia, Brazil / Parasitos do marisco-do-mangue, Mytella guyanensis (Bivalvia: Mytilidae), na Baía de Camamu, Bahia

This contribution reports the parasites found in the mangrove mussel Mytella guyanensis in Camamu Bay, Bahia, Brazil. Samples were collected monthly from September 2006 through October 2007. A total of 460 individuals were collected, fixed in Davidson's solution, and processed by standard histological techniques, and the sections were stained with Harris hematoxylin and eosin (H&E). The water temperature ranged from 23.5 to 31.6 ºC, and the salinity from 25 to 37‰. Microscopic analysis showed Rickettsia-like organisms (RLOs), Nematopsis sp. (Apicomplexa), and Platyhelminthes, including a turbellarian, sporocysts of Bucephalus sp., metacercariae, and metacestodes of Tylocephalum sp. Parasites were observed mainly in the gills, mantle, and digestive gland. The prevalence of Nematopsis sp. was 100%, and in heavily infected mussels the tissues of the labial palps were damaged. RLOs occurred in high prevalence and intensity of infection in some periods. The digenean sporocysts showed moderate prevalence but high intensity of infection, and caused parasitic castration. In general, there was no significant spatial or temporal variation (p > 0.05) of the parasites, which is probably attributable to the small variations of temperature and salinity in the region.

Neste estudo, foram investigados os parasitos de Mytella guyanensis da Baía de Camamu (BA). As amostragens foram feitas mensalmente entre setembro de 2006 e outubro de 2007 e totalizaram 460 animais, que foram fixados em solução de Davidson e processados por técnica rotineira de histologia, com inclusão em parafina e coloração por hematoxilina de Harris e eosina. Foram evidenciados organismos assemelhados a Rickettsia (RLOs); Nematopsis sp. (Apicomplexa) e Platyhelminthes, incluindo um turbelário, esporocistos de Bucephalus sp. e o cestoide Tylocephalum sp. Os parasitos foram encontrados principalmente nas brânquias, no manto e na glândula digestiva. Todos os animais apresentaram Nematopsis sp., o que causou alteração nos palpos labiais em exemplares com alta infecção. RLOs ocorreram em alta prevalência e intensidade de infecção em alguns períodos. Esporocistos de trematódeos digenéticos, com prevalência moderada, mostraram-se em alta intensidade de infecção e causaram castração parasitária. Não houve variação temporal e espacial significativa (p > 0,05) dos parasitos, o que provavelmente se deveu à pequena amplitude de variação da temperatura e da salinidade na região.

Ultrastructural analysis of the dorsal body gland of the terrestrial snail Megalobulimus abbreviatus (Becquaert, 1948) / Análise ultraestrutural da glândula corpo dorsal do caracol terrestre Megalobulimus abbreviatus (Becquaert, 1948)

The ultrastructure of the reproductive gland, dorsal body (DB), of Megalobulimus abbreviatus was analysed. Electron microscope immunohistochemistry was used to detect FMRFamide-like peptides in the nerve endings within this gland. Nerve backfilling was used in an attempt to identify the neurons involved in this innervation. In M. abbreviatus, the DB has a uniform appearance throughout their supraesophageal and subesophageal portions. Dorsal body cells have several features in common with steroid-secreting gland cells, such as the presence of many lipid droplets, numerous mitochondria with tubular cristae and a developed smooth endoplasmic reticulum cisternae. Throughout the DB in M. abbreviatus numerous axonal endings were seen to be in contact with the DB cells exhibiting a synaptic-like structure. The axon terminals contained numerous electron-dense and scanty electron-lucid vesicles. In addition, the DB nerve endings exhibited FMRFamide immunoreactive vesicles. Injection of neural tracer into the DB yielded retrograde labelling of neurons in the metacerebrum lobe of the cerebral ganglia and in the parietal ganglia of the subesophageal ganglia complex. The possibility that some of these retrograde-labelled neurons might be FMRFamide-like neurons that may represent a neural control to the DB in M. abbreviatus is discussed.

Foi analisada a ultraestrutura da glândula reprodutiva corpo dorsal (CD) de Megalobulimus abbreviatus. Imunoistoquímica para microscopia eletrônica foi utilizada para detectar peptídeos relacionados ao tetrapeptídeo FMRFamida nas terminações axonais existentes nessa glândula. Foi utilizada marcação neuronal retrógada com o intuito de localizar os neurônios envolvidos nesta inervação. O CD de M. abbreviatus possui um aspecto uniforme em toda sua extensão, tanto na porção supraesofágica como subesofágica. As células do CD possuem várias características de glândulas esteroidogênicas, tais como a presença de inúmeras gotículas lipídicas, numerosas mitocôndrias com cristas tubulares e cisternas bem desenvolvidas de retículo endoplasmático liso. Por toda a extensão do CD de M. abbreviatus foram encontradas numerosas terminações axonais fazendo contatos estruturalmente semelhantes a sinapses com as células do CD. As terminações axonais continham grande número de vesículas eletrodensas e esparsas vesículas eletrolúcidas. As terminações axonais no CD apresentavam vesículas com conteúdo imunorreativo à FMRFamida. A injeção de traçador neural no CD resultou em marcação retrógrada de neurônios no metacérebro dos gânglios cerebrais e nos gânglios parietais do complexo ganglionar subesofágico de M. abbreviatus. É discutida a possibilidade de que estes neurônios identificados por marcação retrógrada possam representar a via de controle neural do CD de M. abbreviatus, cujo mediador químico seria um neuropeptídeo relacionado à FMRFamida.

Utilização da análise de coliformes como indicativo de sanidade dos mexilhões Perna perna (Linnaeus, 1758) cultivados na ilha Guaíba, Rio de Janeiro / Coliform enumeration used as a sanitation indicative factor from Perna perna (Linnaeus, 1758) mussels cultivated in Guaíba Island, Rio de Janeiro

O mexilhão Perna perna é a espécie de molusco bivalve predominante nas fazendas marinhas de todo o Brasil. O monitoramento bacteriológico de moluscos comercializados deve ser realizado frequentemente devido aos bivalves serem capazes de bioacumular patógenos presentes na coluna d’água onde crescem. Os mexilhões são animais filtradores utilizados para alimentação humana. Portanto, a contaminação ambiental afeta tanto a sanidade do animal quando a Saúde Coletiva. Os níveis de coliformes totais e termotolerantes presentes nos moluscos foram determinados através da técnica do Número Mais Provável (NMP) de abril de 2007 a março de 2008. Os níveis de coliformes totais nos tecidos dos mexilhões variaram de 0,27 a 160,94 NMP.g-1, enquanto os termotolerantes estiveram entre < 0,18 e 35,73 NMP.g-1. É possível que os coliformes presentes em tais concentrações sejam capazes de tornar os moluscos mais susceptíveis a fatores de estresse durante sua comercialização. Análises específicas para cada organismo patogênico e substâncias tóxicas precisam ser desenvolvidas.

The most predominant species of bivalve mollusc cultivated in Brazil’s marine farms is the brown mussel Perna perna. Bacteriological monitoring of commercialized shellfish has to be carried out frequently due to their ability to concentrate pathogens from the water column where they grow up. Mussels are filter-feeding animals used in human diet. Therefore, environmental contamination not only does affect their own sanitation, but also the public health. Total and fecal coliform levels present in shellfish were determined by the Most Probable Number (MPN) technique from April 2007 to March 2008. Total and thermotolerant coliform mean concentrations varied from 0,27 to 160,94 NMP.g-1 and < 0,18 to 35,73 NMP.g-1, respectively. There is a probability that such coliform concentrations are likely to turn mussels more susceptible to stress factors during their commercialization. Specific analyses for each pathogen and toxic substances are still to be carried out.

Estructura de la comunidad de moluscos y relaciones tróficas en el litoral rocoso del estado Sucre, Venezuela / Structure of the mollusk community and trophic relationships in the rocky coast of Sucre state, Venezuela

Mollusc community structure and trophic relations in the rochy littoral zone in Sucre State, Venezuela. We analyzed the structure of a mollusc community and its component trophic relations at six localities within a rocky littoral zone, in Sucre State, Venezuela, including areas that are both exposed to, and protected from, wave energy. Sampling was carried out from March 2003 to Febreuary 2004 period, in an area subdivided in to supralittoral, littoral and sublittoral zones. Samples were collected using hand-held spoons within 0.25 m² quadrats along transects sited perpendicular to the coast line transects. Collected organisms were preserved in 10% formalin for subsequent taxonomic classification. Specific richness and constance were determined, and the four trophic categories of herbivore, suspendivore, carnivore and herbivore-suspendivore were established. Overall 14 581 individual specimens were collected that represented 68 species, 31 families and 9 orders, in the classes Gasteropoda (n=39), Bivalvia (n=23) and Polyplacophora (nn=6). Suspension feeders were the dominant trophic category (49%), followed by carnivores (337%), herbivores (13%) and herbivores-suspension feeders (11%). Herbivores and suspension feeders were dominant in the protected area, while carnivores and suspension feeders were dominant in the exposed area. Data indicate that mollusc distribution and intergroupal trophic relations are controlled by both morphological features and substrate composition. Rev. Biol. Trop. 54 (Suppl. 3): 121-130. Epub 2007 Jan. 15.

Se analizó la estructura de la comunidad de moluscos y sus relaciones tróficas en seis localidades del litoral rocoso con diferentes grados de exposición al oleaje (área expuesta y área protegida), en el Estado Sucre, Venezuela. El muestreo se llevó a cabo durante el período de marzo 2003 a febrero 2004. La recolección del material biológico se realizó de forma manual con ayuda de una espátula, dentro de una cuadrícula de 0.25 m², estableciéndose tres zonas: supra, medio e infralitoral. Los organismos fueron preservados en frascos con formalina al 10% para su posterior análisis. En el laboratorio fueron identificados, contados, y pesados en una balanza de 0.001g de precisión. Se determinó la abundancia total de especies, biomasa, constancia específica y por medio de una revisión bibliográfica se le asignó a cada especie su categoría trófica, clasificándolos en: herbívoros, filtradores, carnívoros y herbívoros -filtradores. Se obtuvo un total de 14 581 individuos (6 397.945 g) representado por 68 especies correspondientes a las clases Gastropoda (39), Bivalvia (23) y Polyplacophora (6); contenidas en nueve órdenes y 31 familias. Los herbívoros fueron el grupo dominante (49%), seguido por filtradores (37%), carnívoros (13 %) y herbívoros-filtradores (1%). Las especies herbívoras y herbívoras-filtradoras dominaron en el área protegida, mientras que en el área expuesta, fueron las carnívoras y filtradoras. Las especies constantes en las seis localidades durante el período de estudio fueron Planaxis nucleus, Mitrella ocellata, M. nycteis, Littorina interrupta, Tegula fasciata, Acmaea leucopleura, Ostrea equestris y Chiton squamosus. La distribución de los moluscos y los diferentes grupos tróficos, pueden estar controlados por adaptaciones morfológicas, así como el nivel de exposición al oleaje y composición del sustrato.

Pesquisa de toxina paralisante dos moluscos em pescado / Investigation of paralyzing toxin from molluscs in fish

A toxina paralisante dos moluscos foi pesquisada em amostras de ostras, mariscos e peixes, colhidas em diferentes praias do litoral paulista. Foram empregados dois procedimentos analíticos: o químico e o bioensaio. Em decorrência do aparecimento de manchas avermelhadas nas águas e mortalidade de peixes na região, no período de agosto a setembro de 1983, suspeitou-se do fenômeno de "maré vermelhra". A toxina não foi detectada em nenhuma das amostras, pelos dois métodos empregados, que permitem segurança dos resultados, considerando que os testes foram realizados com o padrão de saxi toxina (AU).