Academic literature on the topic 'Giant African snail. Snails'

The impact of growth phases on the haemolympy biochemical value of African giant land snail Archachatina marginata was studied. The growth phases were: snailet, juvenile and Adult based on the number of whorls on the shell and weight of the snails. Highest concentration of glucose and lipids were recorded at the juvenile phase (40.20mg/dl), while least values for glucose (20.00mg/dl) and lipids (37.80mg/dl)were recorded during snailer and adult phases respectively. A progressive increase in the concentration of protein was observed as the snails moved from snailetphase to adult phase, hence snails in adult phase had highest concentration of protein in their haemolymph. Growth phases significantly (p<0.05) affected the haemolymph mineral composition of the snails, juvenile phase had the highest values in ca2+,PO4+ and Na+, while the adult phase recorded the least concentration in ca2+, Na amd cl-2. Juvenile growth phase of A. marginata thus has better haemolymph biochemical values than both snailet and adult growth phases.

The impact of management systems on the African giant land snail, Archachatina marginata found in Abeokuta, Nigeria was investigated. The gut microbial load, haemolymph biochemical values (proteins, lipids, glucose, Na+, Ca2+,K+, Cl- PO42+) and proximate composition (crude protein, fat, fibre, ash and carbohydrates) of the flesh were determined in these snails. There were significantly (P<0.05) higher colony forming units (cfu) in the gut of snails from the wild (5.24 x103) than the domesticated snails (3.13 x103). The aemolymph biochemical values and flesh proximate composition were significantly higher in the snails from the wild than the domesticated ones. However, antinutrients and mineral composition of the flesh were not significantly affected by the management systems. The implication of these results on snail meat value in Nigeria is discussed.

There is inadequate information on quality feedstuff for large scale production and all year round availability of snails in Nigeria.The research was conducted to investigate the organoleptic properties of the African giant land snails (Archachatina marginata). Thirtytwo snails were randomly allotted into four dietary treatments of varied levels of 0%, 5%, 10% and 15% rumen content inclusion. Each treatment was replicated with four snails per pen in a completely randomized design. The snails were reared in mini paddock. Feed and water were supplied ad-libitum. At the end of the eight weeks period of feeding trials, two snails were harvested at random from the replicates of each of the four treatments, sacrificed, processed and analyzed. Based on appearance, taste and aroma of the snails fried and stewed with spices and the other one steamed with spices, preference ranking in descending order revealed 15% (6·85) rumen content inclusion had the highest mean preference followed by 5% (6·53) inclusion for the fried snail with spices and 0% (6.65) inclusion had the highest ranking followed by 15% (6.53) rumen content inclusion for the snail steamed with spices. The treatments had no appreciable effect on the nutrient composition and sensory quality of the snail meat. It can be concluded that growing snails can utilize rumen content inclusion thereby increasing the feed data base for snail production in the Tropics.

The African Giant Snail is a dependable source of animal protein for a large proportion of Nigerians. However, in the past few decades, the supply of this Snail and two others of different genera but similar use, has declined. The causes, examined in this paper, which affect its collection and decline in forest reserves are due to a combination of socio-economic and cultural factors: a cultural orientation of the rural dwellers towards the collection and utilization of snails for food, cash, traditional medicine, and sacrifice; indiscriminate destruction of snail habitats due to ignorance or neglect of the resource; and lack of incentives and inadequate data for snail management.Snail collection is a legitimate occupation of rural dwellers. However, because forestry laws in Nigeria regard snails as minor forest products, no legislative, conservational, or management, controls can be effected — hence their collection will continue in future because of their value to Mankind. As the African Giant Snail is fast approaching local endangered status, the fear exists that, unless effective conservation measures are taken urgently, the survival of this biotic resource would appear to be in jeopardy. It is suggested that: (a) representative forests in each ecological zone should be preserved for wildlife conservation; (b) smallholder snail-farming should be encouraged among rural and urban dwellers to de-emphasize its collection from the optimal wild source; and (c) research should be conducted on the ecology and biology of the major snail species to develop a database from which their management within the reserves can be effected.

Two species of snails (Achatina achatina and Archachatina ventricosa), from surrounding forest of Azaguié’s district, were collected at the market of the locality aforementioned in order to identify their various parasites. For that, 50 snails of each species were sacrificed. Parasites were searched on the level of the flesh, between the flesh and the shell, the stomach, the intestine, the liver and the reproductive apparatus. The collected parasites were Balantidium spp, the larvae of Protostrongylus spp, the larvae of Dicrocoelium spp and Trichomonas spp. Our results showed that 52% of Achatina achatina and 74% of Archachatina ventricosa were parasitized. Among the parasites collected in the snail Achatina achatina, 95.8% were nematodes and 4.1% were trematodes. Whereas in the snail Archachatina ventricosa, 97.7% were protozoa, 8.8% nematodes and 0.4% consisting with trematodes. The prevalence of Protostrongylus spp (48%) were higher than that of Dicrocoelium spp (4%) in Achatina achatina. For the snail Archachatina ventricosa, the prevalence of parasite were dominated by Trichomonas spp (38%) and Protostrongylus spp (24%).

This review focuses on biologically active entities from invertebrate sources, especially snails. The reader will encounter several categories of compounds from snails including glycosaminoglycans, peptides, proteins (glycoproteins), and enzymes which possess diverse biological activities. Among glycosaminoglycans, acharan sulfate which was isolated from a giant African snail Acahtina fulica is reviewed extensively. Conotoxins which are also called conopeptides are unique peptide mixtures from marine cone snail. Conotoxins are secreted to capture its prey, and currently have the potential to be highly effective drug candidates. One of the conotoxins is now in the market as a pain killer. Proteins as well as glycoproteins in the snail are known to be involved in the host defense process from an attack of diverse pathogens. Carbohydrate-degrading enzymes characterized and purified in snails are introduced to give an insight into the applicability in glycobiology research such as synthesis and structure characterization of glycoconjugates. It seems that simple snails produce very complicated biological compounds which could be an invaluable source in future therapeutics as well as research areas in natural medicine.

The morphometry of the reproductive organs of the giant African land snail, Archachatina marginata ovum from wild collection at Ile-Ife, southwest Nigeria, was assessed during March - May (early rainy season) and August – October (late rainy season) of 2010. A total 134 snails were dissected and clas-sified into one of five different reproductive states (low mating readiness; high mating readiness; egg production; gravid and post reproductive). The five states were observed in snails collected during the early rainy season, whereas the gravid state was not observed in the collections during late rainy sea-son. Albumen gland was considerably enlarged at egg production state forming about 60 % of the total weight of the reproductive system, while vas deferens was significantly longer in snails at high mating readiness state. The sizes of the reproductive organs were not substantially related to the size of the snail as the coefficient of determination (r2) of the relationship were in most cases below 0.5. The over-all results indicated that variations in the morphology of the reproductive organs of A. marginata ovum are mostly state dependent and less related to the size of the snail and thus could be used reliably to categorise the snails into reproductive states.

Background: The giant African snail, Achatina fulica, is an invasive species recognized for being a serious agricultural pest and an intermediary vector for diverse parasites that cause diseases in humans. The knowledge of the state of African snail populations in urban areas is of great ecological and public health importance. Therefore, our objective was to characterize the status of giant African snail populations present in the city of Cartagena, Colombia, including the assessment of nematode parasites in the specimens. Methods. Sites were visited following information from citizens affected by the presence of the African snail. The specimens were collected and transported to the laboratory; subsequently, they were weighed, measured, and classified by size. Dissections of lung tissue and soft organs were performed to search for and identify nematode parasites. Size measurement between the sampled sites was statistically compared and density and biomass indicators were established. Results. In total, 204 snails were collected distributed among four sites within Cartagena city. Of these, 50% were juvenile specimens (10-40 mm). The size of the specimens showed significant differences between the sampling areas. The calculated density was between 0.0019-0.68 ind/m2 and the biomass between 3.92-48.75 kg/ha. No presence of nematode parasites was observed in these specimens. Conclusions. Densities and biomasses of A. fulica in Cartagena do not reach levels considered highly harmful. On the other hand, although no parasites were found in these snails, it is relevant to continue with studies on the human health risks that represent the presence of this invasive species in urban areas of Cartagena.

Background: The giant African snail, Achatina fulica, is an invasive species recognized for being a serious agricultural pest and an intermediary vector for diverse parasites that cause diseases in humans. The knowledge of the state of African snail populations in urban areas is of great ecological and public health importance. Therefore, our objective was to characterize the status of giant African snail populations present in the city of Cartagena, Colombia, including the assessment of nematode parasites in the specimens. Methods. Sites were visited following information from citizens affected by the presence of the African snail. The specimens were collected and transported to the laboratory; subsequently, they were weighed, measured, and classified by size. Dissections of lung tissue and soft organs were performed to search for and identify nematode parasites. Size measurement between the sampled sites was statistically compared and density and biomass indicators were established. Results. In total, 204 snails were collected distributed among four sites within Cartagena city. Of these, 50% were juvenile specimens (10-40 mm). The size of the specimens showed significant differences between the sampling areas. The calculated density was between 0.0019-0.68 ind/m2 and the biomass between 3.92-48.75 kg/ha. No presence of nematode parasites was observed in these specimens. Conclusions. Densities and biomasses of A. fulica in Cartagena do not reach levels considered highly harmful. On the other hand, although no parasites were found in these snails, it is relevant to continue with studies on the human health risks that represent the presence of this invasive species in urban areas of Cartagena.

A number of studies have been carried out on the reproductive and growth performance of these breeds of giant African land snails, but not much is documented on chromosome, evolutionary relationships and divergence studies. Forty snails and 10 of each breed of giant African land snails Archachatina marginata (AM), Achatina achatina (AA) and Achatina fulica (AF) and two varieties of A. marginata [A. marginata var. saturalis (AMS) and A. marginata var. ovum (AMO)] were used for the chromosomes numbers analyses. Slides for chromosome identification were prepared using the ovotestes and the cells were examined for spread atmetaphase. The haploid (n) chromosome numbers obtained revealed and confirmed that AF, AA, AMS and AMO snails have 27, 30, 28 and 28 chromosomes respectively. Also 13 amino acid sequences were retrieved from the National Centre for Biotechnology Information with accession numbers: ALD09273, AAY62497, ACA 10148 and AKQ 76237 for AM; AKQ 76253, AKQ 76250, CDL 67813, CDL 67813 and AKQ 76249 for AA and SP/P35903, PDB/5CZL, KZM 80032 and YP009049167 for AF snails. The evolutionary history was inferred using the Neighbour-Joining method. Phylogenetic tree analysis by Neighbour- Joining (NJ) was constructed using 10 out of the 13 amino acid sequences. The reliability of the tree was calculated by boostrap confidence value with 1000 boot strapiterations using MEGA 7 software.The phylogenetic trees showed that these snail breeds are highly divergent. A. achatina was separately related to itself; whereas A. marginata slightly mingled with A. fulica. The degrees of divergence obtained signified that they have evolved from different ancestors. The evolutionary distances were computed with the remaining three amino acid sequences using the Poisson Correction method. Very high and far apart average genetic distances of 0.923±0.018, 0.926±0.018 and 0.926±0.017 were obtained for AA vs AF, AF vs AM and AA vs AM snails respectively, confirming that these snail breeds are genetically far apart between themselves. The results obtained for chromosome numbers, evolutionary relationship and average genetic distances might be apanacea in further selection and molecular classification of giant African land snails (GALS) in Nigeria.

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Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB
The African snail Achatina fulica Bowdich, 1822, is an invasive species that cause environmental and economic damage, as to human and animal health. The aim of this study was to evaluate the occurrence and parasitological aspects of A. fulica in Feira de Santana (BA). To assess the occurrence of A. fulica, sampling was made from January to June 2013 at four points in the urban perimeter of the city. In the laboratory animals were measured as the total length of the shell and the total mass. From these data the degree of development of the population was estimated, and the relationships between morphometric and climatic variables and the condition factor were calculated. During this period were collected 600 snails showing predominant length in the range of 57.0 to 47.6 mm. Results allowed to infer that the population of A. fulica in these sampling points is in decline, since in these areas were found juvenile and young animals. There was no association between climatic and morphometric variables. The relationship between total length and weight showed that A. fulica presented a negative allometric growth. The condition factor presented variations on time over the six months of collection. In order to evaluate parasitological aspects in A. fulica, animals were collected from may 2012-to june 2013 in eight areas in the urban perimeter of the city.The animals were collected early in the morning and transported to the laboratory of the Zoonoses and Public Health Research Group -UEFS. Each clam was analyzed individually using the artificial digestion technique in hydrochloric acid solution with identification of larvae found. The larvae have been identified as Metastrongylidae were submitted to the polymerase chain reaction for the identification of the genus Angyostrongylus. 220 animals were tested and in 28 (12.7; 95: 8.6 -17.9) were found at least one of four morphotypes of nematodes. Angyostrongylus has not been registered in snails examined. There was no association between climatic variables and the presence of larvae. The location of collection and the size of the snail influenced in the larvae of nematodes. Both parasited and not parasitised animals have negative allometric growth. The relative condition factor did not differ significantly between the groups. Nested-PCR has been used to search Cryptosporidium ssp and Sarcocystidae DNA in fecal samples of Achatina fulica. Amplicons compatibles with Cryptosporidium ssp were found in 2 of 223 stool samples analyzed. Of the 223 stool samples analysed, in 58 samples we found the 290 base pair fragment expected for Sarcocystidae, and then subjected to RFLP. Of these, 41 samples were cleaved by enzymes used in this study, producing a profile compatible with T. gondii. The other 17 samples were not compatible with Sarcocystidae. This is the first record of the occurrence of A. fulica in Feira de Santana (BA), with research of association of climatic variables to the biometric parameters of the animals. These results indicate the presence of animal and humana parasites in Achatina fulica in the municipality of Feira de Santana, demonstrating the potential of these animals in the maintenance and spread of these agents in the environment.
O caramujo africano Achatina fulica Bowdich, 1822, ? uma esp?cie invasora que causa preju?zos ambientais, econ?micos e a sa?de humana e animal. O objetivo desse estudo foi avaliar a ocorr?ncia e os aspectos parasit?rios de Achatina fulica no munic?pio de Feira de Santana (BA). Para avalia??o da ocorr?ncia de A. fulica foram feitas coletas de janeiro a junho de 2013 em quatro pontos no per?metro urbano do munic?pio. No laborat?rio os animais foram mensurados quanto ao comprimento total da concha e a massa total. A partir desses dados o grau de desenvolvimento da popula??o foi estimado, as rela??es entre as vari?veis morfom?tricas e clim?ticas e o fator de condi??o foram calculados. Durante esse per?odo foram coletados 600 caramujos apresentando comprimento predominante no intervalo de 47,6-57,0mm. Os resultados permitiram inferir que a popula??o de A. fulica nos pontos de coleta estudados est? em decl?nio, j? que nessas ?reas foram encontrados animais juvenis e jovens. N?o houve associa??o entre as vari?veis clim?ticas e morfom?tricas. A rela??o entre o comprimento total e a massa corporal mostrou que A. fulica apresentou um crescimento alom?trico negativo. O fator de condi??o apresentou varia??es pontuais ao longo dos seis meses de coleta. A fim de avaliar os aspectos parasit?rios em A. fulica foram realizadas coletas de maio de 2012 a junho de 2013 em oito ?reas no per?metro urbano do munic?pio, com registro de observa??es sobre os locais de coleta. Cada molusco foi analisado individualmente utilizando a t?cnica de digest?o artificial em solu??o de ?cido clor?drico, com identifica??o das larvas encontradas. As larvas identificadas como Metastrongylidae foram submetidas ? rea??o em cadeia pela polimerase para a identifica??o do g?nero Angyostrongylus. Foram analisados 220 animais e em 28 (12,7%; IC95%: 8,6-17,9) foram encontrados pelo menos um de quatro morfotipos de nemat?deos. Angyostrongylus n?o foi registrado nos caramujos examinados. N?o houve associa??o entre vari?veis clim?ticas e a presen?a de larvas. O local de coleta e o tamanho do caramujo influenciaram no encontro de larvas de nemat?deos. Tanto animais parasitados quanto n?o parasitados apresentaram um crescimento alom?trico negativo. O fator de condi??o relativo n?o diferiu significamente entre os grupos. A fim de pesquisar a presen?a de DNA Cryptosporidium ssp. e Sarcocystidae nas amostras fecais de Achatina fulica foi utilizada a t?cnica de nested-PCR (nPCR). Para Cryptosporidium ssp., amplicons compat?veis com este parasito foram encontrados em 2 de 223 amostras de fezes analisadas. Das 223 amostras de fezes de Achatina fulica submetidas ? nPCR para detec??o de Sarcocystidae, 58 amostras amplificaram o fragmento esperado de 290 pares de base, sendo ent?o submetidas ? RFLP. Destas, 41 amostras foram clivadas pelas enzimas utilizadas nesse estudo, produzindo um perfil compat?vel com T. gondii. As outras 17 amostras n?o foram compat?veis com o Sarcocystidae. Este ? o primeiro registro da ocorr?ncia de A. fulica no munic?pio de Feira de Santana (BA), com pesquisa da associa??o das vari?veis clim?ticas aos par?metros biom?tricos dos animais estudados. Estes resultados indicam que h? presen?a de parasitos de interesse em sa?de animal e humana em Achatina fulica no munic?pio de Feira de Santana, Bahia, demonstrando o potencial destes animais na manuten??o e dispers?o destes agentes no ambiente.

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The snail, Achatina fulica (Giant African snail), is registered in almost all Brazilian territory, and may act as an intermediate host of parasites of the man. This study aimed to describe the morphology of the nematode larvae found in A. fulica, through light (LM) and scanning electron microscopy (SEM), and to relate the prevalence of infection to the collection places of the snails and to the antropic activity. Sixty snails were collected from April/2006 to April/2007, in the Mesquita City, RJ, transferred to laboratory, kept in terraria, measured and dissected to verify the infection, distribution of the cysts in tissues of the snails. The cysts were collected and the larvae were separated. The material thus obtained was used to LM and SEM. The occurrence of A. fulica in the less conserved area was greater than that in the more conserved area. However, there was not a significant relation between the intensity of infection and the collection places and the antropic activity. Fourteen snails (23%) were infected and the biggest number of cysts/snail verified was 130 and the minor was 1, in snails that with 106 and 55mm of shell length, respectively. A strong correlation was observed between the size of the snail and the number of cysts and there was a greater concentration of these in the pallial cavity, 87%. Of this total, 49% were in the area more vascularized and 38% in the less vascularized area of this cavity. The cysts presented spherical shape, light pink colored and measured 0.97-1.57mm in diameter and with an unique larva involved by an amorphous material. Two hundred twenty two encysted larvae were recovered, 30 larvae were used to the morphological studies. The length of the larvae varied of 2.57-5.8mm, being classified in: small - until 3.5mm; medium - of 3.53-4.5mm and great - above of 4.52mm. The average length of the larvae in the three groups was of 2.85; 3.87 and 5.23mm, respectively, and the total average of 4.2mm. The larvae presented white cuticle, shining, transversally striated and the lateral line extending to the posterior extremity of the body. In the anterior end, it is observed mouth provided with three lips, with amphids and papillae, followed by a muscular oesophagus with average length of 0.61mm, ending in an esophagus bulb. The nervous ring it was observed in the medium third of the oesophagus and the intestine ends in an opening located next to the posterior end. The tail had a length varying of 0.15-0.42mm, is located after this opening may present two types of endings: abrupt or that it sharpens gradually. The difference in the ending of the tail may suggest sexual dimorphism, although not to have been observed reproductive structures. The identification to the specific level was not possible, this pointed to the necessity of continuation of this study. The expressive population density of A.fulica observed in the conserved area less it confirms the influence of the antropic action on the dispersion of this snail.
O molusco Achatina fulica (Caramujo gigante africano) ? registrado em quase todo territ?rio nacional, havendo a possibilidade de atuar como hospedeiro de parasitos do homem. Este estudo objetivou descrever a morfologia dos est?gios larvais de nemat?ides encontrados em A. fulica, atrav?s de microscopia de luz e eletr?nica de varredura, e relacionar a preval?ncia de infec??o aos locais de coleta dos moluscos e ? atividade antr?pica. Sessenta moluscos foram coletados de abril de 2006 a abril de 2007, no munic?pio de Mesquita, RJ, transferidos para o laborat?rio, mantidos em terr?rios, medidos e dissecados para verifica??o da infec??o, distribui??o dos cistos pelos tecidos do molusco, coleta dos cistos e obten??o das larvas. Procedeu-se a fixa??o e o processamento para microscopia de luz e eletr?nica de varredura. A ocorr?ncia de A. fulica na ?rea menos conservada foi maior que na ?rea mais conservada. Por?m n?o houve uma rela??o significativa entre a intensidade de infec??o aos locais de coleta e ? atividade antr?pica. Quatorze moluscos (23%) estavam infectados e o maior n?mero de cistos verificado por molusco foi de 130 e o menor de 01, em moluscos que apresentavam 106 e 55mm de comprimento de concha, respectivamente. Foi observada uma forte correla??o entre o tamanho do molusco e o n?mero de cistos encontrados e maior concentra??o destes na cavidade paleal, 87%. Desse total, 49% estavam na ?rea mais vascularizada e 38% na menos vascularizada da cavidade. Os cistos apresentavam formato esf?rico, colora??o rosada e mediam de 0,97 a 1,57mm de di?metro e na maioria das vezes com uma ?nica larva que se encontrava envolvida por um material amorfo. Foram recuperadas 222 larvas encistadas. Destas, 30 foram utilizadas no estudo morfol?gico. O comprimento das larvas variou de 2,57 a 5,8mm, sendo classificados em: pequeno at? 3,5mm; m?dio de 3,53 a 4,5mm e grande - acima de 4,52mm. O comprimento m?dio das larvas nos tr?s grupos foi de 2,85; 3,87 e 5,23mm, respectivamente, e a m?dia total de 4,2mm. As larvas apresentavam cut?cula branca, brilhante e estriada no sentido transversal e linha lateral at? a extremidade posterior do corpo. Na extremidade anterior, observa-se a boca provida de tr?s l?bios, com anf?dios e papilas, seguida por um es?fago musculoso com comprimento m?dio de 0,61mm, terminando em um bulbo esofagiano. O anel nervoso foi observado no ter?o m?dio do es?fago e o intestino termina em uma abertura localizada pr?ximo ? extremidade posterior. A cauda, com comprimento variando de 0,15 a 0,42mm, se forma a partir desta abertura e apresenta dois tipos de termina??es: abrupta ou que afina gradativamente. A diferen?a na termina??o da cauda pode sugerir dimorfismo sexual, apesar de n?o terem sido observados prim?rdios de ?rg?os reprodutores. Com os resultados obtidos n?o foi poss?vel a identifica??o ao n?vel espec?fico, havendo dessa forma a necessidade de continua??o deste estudo. A densidade populacional expressiva de A. fulica observada na ?rea menos conservada confirma a influ?ncia da a??o antr?pica sobre a dispers?o deste molusco.

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Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil.
Achatina fulica, ou caramujo africano, foi introduzido no Brasil em meados da década de 1980 para ser comercializado como “escargot”. No entanto, em virtude da baixa demanda do mercado consumidor, os criadores desativaram seus plantéis, gerando fuga ou liberação intencional de exemplares que, livres no ambiente, espalharam-se rapidamente por quase todo país (24 estados mais o Distrito Federal). As “densas” populações do caramujo africano causam uma série de problemas, como a destruição de hortas e jardins, competição com a fauna nativa, além de poderem transmitir zoonoses como a angiostrongilose abdominal e a meningite eosinofílica. A exemplo do que ocorre em outras partes do país, o Município de Barra do Piraí, Estado do Rio de Janeiro, encontra-se também infestado. Visando contribuir para o enfrentamento dos danos causados por essa espécie, o presente estudo objetivou: pesquisar a helmintofauna de populações de A. fulica em alguns bairros de Barra do Piraí quanto à presença de larvas de helmintos de importância médico-veterinária; analisar as percepções relacionadas ao caramujo africano entre estudantes do Ensino Fundamental de uma escola pública estadual no referido município. A pesquisa, de abordagem qualitativa, foi realizada em duas etapas: 1) coleta de exemplares de A. fulica nos bairros Arthur Cataldi, Dorândia, Química, Boca do Mato e São João no período de fevereiro de 2008 a novembro de 2009, os quais foram analisados no Laboratório de Malacologia do Instituto Oswaldo Cruz/Fiocruz (Referência Nacional em Malacologia Médica); 2) aplicação de 82 questionários e a realização de quatro grupos focais com alunos do Ensino Fundamental, além de observações de campo. Os resultados obtidos ao longo do trabalho “comprovam” que há uma infestação de caramujos africanos no município. A pesquisa da helmitofauna revelou que caramujos provenientes de dois dos cinco bairros analisados, quais sejam, Química e Dorândia, apresentaram o nematódeo Angiostrongylus cantonensis causador da meningite eosinofílica no homem. Além disso, também foram encontrados no município os nematódeos Strongyluris-like e Aelurostrongylus abstrusus que causam doenças em animais. Os dados referentes ao estudo das percepções revelaram que os alunos identificam a presença do caramujo africano no contexto no qual estão inseridos, e embora a maioria acredite que esse animal possa causar doenças, apenas uma minoria afirma conhecer pessoas que tiveram problemas com o caramujo. Os dados igualmente apontam para divergências entre a visão dos alunos e o conhecimento científico sobre as formas de controle de A. fulica e os tipos de agravos, em função do contato ou ingestão dessa espécie. Os laudos referentes ao exame dos moluscos e as recomendações aos órgãos municipais sobre o controle e monitoramento A. fulica já foram encaminhados à secretaria de saúde do município para que sejam tomadas as devidas providências. Da mesma forma o trabalho será disponibilizado aos professores da escola que participou desta pesquisa para que suas contribuições possam auxiliar na prática docente. Espera-se que os resultados deste trabalho possam subsidiar o desenvolvimento de ações de controle e monitoramento de A. fulica no município, bem como ações educativas em contextos formais e não formais de ensino para trabalhar com essa temática, adequadas à realidade da comunidade.
The giant African snail Achatina fulica, was introduced in Brazil in mid-1980 for commercial purposes ("escargot" farming) that were not successful. In spite of marketing efforts the demand was low since Brazilians are not used to eat terrestrial snails. Thus, farmers gave up rearing the snails and unaware of the potential negative consequences released the snails by putting them in the garbage, discarding them on waste land and the edges of highways or throwing them into the rivers. The result was a quick spread throughout most of the country (24 states plus the Federal District). The "dense" populations of A. fulica cause many of problems, such as nuisance and destruction of vegetable gardens and gardens. They may also transmit zoonosis such as abdominal angiostrongylosis and meningoencephalitis. Similarly to other municipalities in the state of Rio de Janeiro, Barra do Piraí is also infested. The present study aimed to investigate the larval helminthes of medical and veterinary importance associated with populations of A. fulica in some districts of that municipality as well as analyze the knowledge and perceptions about that snail among students in a public school. Therefore, methodological procedures were performed in two steps: 1) collecting of specimens of A. fulica from five neighborhoods from February 2008 to November 2009, which were analyzed at the Laboratory of Malacology (Instituto Oswaldo Cruz/Fiocruz), a National Center for Medical Malacology Research; 2) application of 82 questionnaires and conducting four focus groups with elementary school students, and field observations. The search for larval helminthes detected the presence of nematodes of medical-veterinary importance: Strongyluris-like, Aelurostrongylus abstrusus and Angiostrongylus cantonensis larvae (causes eosinophilic meningitis in humans) in the neighborhoods of Química and Dorândia. As for the study of the perceptions the data revealed that students identify the presence of the African snail in the context in which they live. Most of the students believe that the snail can cause disease, but a minority said that knew the health problems related to this animal or even people who had them. The data also point to differences between students' views and scientific knowledge on ways to control A. fulica and the types of injuries, depending on contact or ingestion of this species. The reports concerning the examination of snails and recommendations to the municipal authorities over the control and monitoring A. fulica have been forwarded to the secretary of health of the city for taking appropriate action. Moreover, the work will be available to school teachers who participated in this survey for their contributions to assist in teaching. It is hoped that the results of this study may support the development of control measures and monitoring of A. fulica in the county, as well as educational activities appropriate to the reality of the community.

碩士
國立臺灣大學
藥理學研究所
87
Summary The effects of serotonin (5-HT) were studied in the central neurons of the giant African snails ( Achatina fulica ) . 5-HT (30 microM) elicited bursting activity of action potentials in Achatina fulica central RP7 neuron but not RP8 and LP4 neurons . The 5-HT-elicited bursting was not inhibited after continuous perfusion with hexamethonium (50 microM), d-tubocurarine (100 microM), atropine (1mM), prazosin (100 microM), propranolol (100 mciroM), haloperidol (260 microM), NAN-190 (50 microM), ketanserin (100 microM), mianserin (50 microM) and MDL-72222 (10 microM) . These results suggest that the bursting activity elicited by 5-HT was not due to the cholinergic, adrenergic, dopaminergic, 5-HT1A, 5-HT2 and 5-HT3 receptors of the excitable membrane. Prior treatment with high Mg2+ (30mM), K+ -free, low Ca2+ (50%) and low Na+ (50%) solution didn't inhibit 5-HT to elicit bursting of action potentials in RP7. 5-HT-elicited bursting wasn't inhibited after continuous perfusion with high Mg2+ (30mM), K+-free, low Ca2+ (50%) and low Na+ (50%) solution. These results suggest that the bursting activity elicited by 5-HT may not directly involve in extracellular K+, Ca2+, Na+ and synaptic effects of neurotransmitters. The 5-HT-elicted bursting activity was potentiated by forskolin (adenylate cyclase activator) and was mimicked by forskolin together with isobutylmethylxanthine (IBMX, phosphodiesterase inhibitor). The 5-HT-elicited bursting was suppressed by prior treatment with 2',5'-dideoxyadnosine ( adenylate cyclase inhibitor ). These results suggest that 5-HT may elicit bursting of action potentials through cAMP in RP7 neuron of Achatina fulica. It's concluded that 5-HT may elicit bursting of action potentials through cAMP in RP7 neuron of Achatina fulica and that the 5-HT-elicited bursting of action potentials may not directly involve in extracellular K+, Ca2+, Na+ , synaptic effects of neurotransmitters, the cholinergic, adrenergic, dopaminergic, 5-HT1A, 5-HT2 and 5-HT3 receptors of the excitable membrane.

碩士
國立臺灣大學
藥理學研究所
82
The toxic effect of d-amphetamine was studied on the neuron of the giant African snail(Achatina fulica). of d-amphetamine (271μM) to RP4 neuron of Achatina fulica at temperature induced a characteristic bursting activity of action potentials. The bursting activity was not inhibited by perfusing with (1) high Mg2+ (25 mM)solution (2) hexamethonium (50μM) (3) - tubocurarine (100μM) (4) atropine(1mM) (5)propranolol(100μM) (6) prazosin (100μM) (7) yohimbine(100μ M) (8) haloperidol M)and (9) Ca2+ free solution.The bursting activity was markly antagonized by perfusing with (1) low-Na+ (20mM) solution and (2) cold physiological solution (2~30 C). Inhibition of Na+pump by both ouabain and K+-free solution also decreased the bursting activity of actionpotentials induced by d-amphetamine. However, d-amphetamine at higher concentration(813μM) did not induce any bursting activity on other central snail neuron ,such as . These results indicate that d- amphetamine may selectively affect the excitability ofthe neural membrane to cause the bursting activity. The effect may be involved in theelectrogenic sodium pump of the neuron.

碩士
國立臺灣大學
藥理學研究所
85
The effect of l-amphetamine and 5-HT was studied on the central neuron of the giant African snails ( Achatina fulica ) . Administration of l-amphetamine ( 0.3 mM ) and 5-HT ( 0.3 mM ) to RP4 neurons of Achatina fulica induced a characteristic bursting activity of action potentials. The bursting activity induced by l-amphetamine was inhibited by high-potassium solution, sodium-free solution . Administration of ouabain or high concentration of tetrodotoxin would inhibit the bursting activity induced by l-amphetamine. These results indicated that the bursting activity induced by l-amphetamine may involve with sodium pumps ,and some TTX-resistant sodium channels. The bursting activity induced by 5-HT was inhibited by ouabain, but was not antagonized by sodium-free sloution, potassium-free solution, calcium-free solution, and lithium ( which substituted for sodium ) solution. These results suggested the bursting activity induced by 5-HT may involved with sodium pumps of cell membrane. The mechanisim of l-amphetamine and 5-HT are not fully the same, but it is possible that they share the same intracellular secondary messenger pathway.