100 resultados para Mystacina tuberculata


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Melanoides tuberculata (Müller, 1774), molusco exótico límnico de origem afroasiática, foi registrado pela primeira vez na Vila do Abraão, Ilha Grande, Angra dos Reis, Rio de Janeiro, em 2005. Atua como primeiro hospedeiro intermediário de diversos trematódeos de importância médica. As populações são compostas majoritariamente por fêmeas partenogenéticas que possuem um marsúpio onde se desenvolvem os juvenis. Os objetivos foram verificar: a presença de machos; se existem flutuações na produção de ovos e juvenis ao longo do tempo; quando a maturidade sexual é atingida e, a existência de parasitos relacionando sua presença com o número de ovos e juvenis. Para a contagem de ovos e juvenis, foram utilizadas fêmeas coletadas bimestralmente de setembro/07 a outubro/10, separadas em quatro classes de tamanho, segundo o diâmetro da concha: Classe I: < 3mm; Classe II: 3 a 5,99mm; Classe III: 6 a 8,99mm; Classe IV: > 9mm. Separamos cinco fêmeas/classe, totalizando 20 fêmeas/coleta, exceto nas amostras de setembro/07 (16 exemplares), abril/09 (19 exemplares) e de abril/10 (13 exemplares), totalizando 348 fêmeas. Para observação dos parasitos, ovos e juvenis o teto da cavidade palial foi retirado e o marsúpio dissecado. Classificamos os juvenis em classes de acordo com o número de voltas: com menos de duas; com duas a quatro e com mais de quatro. Os dados foram analisados utilizando Excel e SYSTAT 12. Para a histologia da gônada e do marsúpio, utilizamos cinco exemplares coletados mensalmente de setembro/12 a fevereiro/13, de cada classe de tamanho, totalizando 20 espécimes/coleta, exceto em outubro/12, quando 16 espécimes foram usados, pois somente um espécime da Classe IV foi encontrado. Os espécimes foram fixados em formalina Millonig de Carson, descalcificados em EDTA, incluídos em parafina e corados em hematoxilina e eosina. Foram encontrados 16 machos. Quantificamos 24.694 ovos e 31.474 juvenis, com as seguintes médias: Classe I: 0 ovos e 0,31 juvenis; Classe II: 24,19 ovos e 47,56 juvenis; Classe III: 114,84 ovos e 155,78 juvenis; Classe IV: 146,76 ovos e 158,41 juvenis. O teste de Kruskal-Wallis mostrou que existe variação significativa no número de ovos e juvenis ao longo do ano (p < 0,01 para ambos) e entre o número de ovos e juvenis entre as diferentes classes de tamanho de concha (p <0,01 para ambos). Foram contabilizados 27.877 juvenis com menos de duas voltas, 3.251 juvenis com duas a quatro voltas e 346 juvenis com mais de quatro voltas. Dentre 348 fêmeas, 111 estavam parasitadas (32% do total) por Centrocestus formosanus (Nishigori, 1924). O Teste de Mann-Whitney, levando em consideração todas as fêmeas, demonstrou que fêmeas parasitadas apresentaram menor número de ovos e juvenis que as não parasitadas ( p<0,01). Excluindo as fêmeas da Classe 1, o resultado do teste foi o mesmo (p< 0,01). Concluímos que: a população de M. tuberculata da Vila do Abraão não é formada somente por fêmeas; as fêmeas se reproduzem o ano todo, pois foram encontrados ovos e juvenis em todas as coletas; que quanto maior a fêmea há mais ovos e, em média, há mais juvenis no marsúpio; que a maturidade sexual é alcançada com aproximadamente 3 mm de diâmetro de concha, devido a presença de ovócitos vitelogênicos tardios e, que o parasitismo afeta negativamente M. tuberculata, reduzindo o número de ovos e juvenis formados

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Dissertação de Mestrado, Estudos Integrados dos Oceanos, 26 Fevereiro de 2016, Universidade dos Açores.

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The spider crab Pyromaia tuberculata was introduced into southeastern Brazil; ovigerous material was collected and reared in the laboratory. Morphologic changes and growth patterns of post-larval development are reported. Results show that within-stage size variation is lowest in mature stages, especially in the case of females in which there is an apparent size threshold for the last juvenile stages to undergo the puberty molt. A prepuberty molt taking place at the fourth crab stage is indicated by analyzing the allometric growth of the abdomen in females. In contrast, the same procedure using the allometric growth of chelae failed in detecting both the prepuberty and puberty molts in males. Conversely to females, which develop a complex brood chamber at the puberty molt, the enlargement of chelae was not consistent in all postpuberty males. The short instar sequence of this species, in no case exceeding nine stages, is marked by conspicuous morphologic alterations achieved at each molt. Almost all stages can be identified by examining diagnostic features of rostrum, abdomen, sternum, and pleopods.

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The larval development of Pyromaia tuberculata (Lockington, 1877) is described from specimens reared in the laboratory. Larvae were obtained from ovigerous females collected by trawl in Ubatuba, São Paulo state, Brazil. Rearing was carried out at 24 +/- 1 degrees C in 35 parts per thousand S. The larvae pass through two zoeal stages before moulting to the megalopa. A comparison is made with previously studied majid species occurring in the southern and southeastern regions of Brazil.

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This work aimed to evaluate the gastrointestinal helminthfauna composition of six-banded armadillos from the Brazilian semi-arid region. Gastrointestinal contents of six road-killed adult animals from Patos County, Paraiba State, were analyzed. Six species of nematodes, comprising five genera and four families, were recovered from the analyzed animals. New morphological data on Trichohelix tuberculata is given, along with a new taxonomical proposal for Hadrostrongylus ransomi (Travassos, 1935) n. comb. This is the first record for parasitic helminths in this host from the Brazilian semi-arid.

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Master Universitario Internacional en Acuicultura

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[EN]Three chemical methods for induction of relaxation in H. tuberculata coccinea (50-80mm shell length) were tested: sodium pentobarbital (60mg/l), 2-phenoxyethanol (2ml/l) and clove oil at three concentrations (0.02, 0.05 and 0,5ml/l). The time taken for animals to release from aquaria walls and recover from the anaesthetics was recorded. No mortality was observed after one week from experiment. All anaesthetics made animals release from container walls within 10-30 min, but they were ineffective as muscle relaxants, leaving the foot hard and contracted. The most effective concentration tested for clove oil was 0,5ml/l at 22ºC.

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Programa de Doctorado: Acuicultura: producción controlada de animales acuáticos

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[EN] Diatom cell quantity and their biochemical composition vary among species and are greatly affected by harvest stage or culture conditions. Biometric parameters, growth, attachment capacity and variations in biochemical composition of four species of benthic diatoms (Amphora sp., Navicula incerta, Nitzschia sp. and Proschkinia sp.) were studied. For biochemical analysis the diatoms were harvested at different stages, in log and stationary phase of growth. The culture conditions were identical for all the experiments, benthic diatoms were cultured during 7 days in F/2 medium at 28.5 ± 1.4 ºC, at different original inoculating densities (50000, 100000, and 250000 cell mL-1), under continuous light of 5403 ± 649 Lux provided by cool white fluorescent lighting. The cultures were neither aerated nor agitated. These results show that the specific density of 10000 cell mL-1 was the best for weekly production: Proschkinia sp. reached the highest cell density of 5.81 x 106 cells mL-1 and Amphora sp. had the highest cell attachment capacity with 12000 cell mm-2, in stationary phase of growth. Protein and lipid content were higher in log phase than in stationary phase for the four diatoms. Amphora sp. in log phase of growth had the highest lipid content of 9.74% dry weight (DW). Polyunsaturated fatty acid (PUFA) content ranged from 23.25% to 38.62% of the total fatty acids (TFA), and the four diatoms tested were richer in n-3 PUFA than in n-6 PUFA. All the diatoms had significant quantities of 20:5n-3 (EPA) ranging between 12.69% and 17.68% of TFA. Benthic diatoms play an important and critical role in abalone culture as they are the principal food source of abalone post-larvae. Therefore, it is necessary to improve diatom quantity and quality to optimize post-larval nutrition and the consistency of production, resulting in an increase in growth and survival of abalones.

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[EN] First description of the complete embryo and larval development of the Canarian abalone (Haliotis tuberculata coccinea Reeve.) was conducted along 39 stages from fertilization to the appearance of the third tubule on the cephalic tentacles and illustrated in a microphotographic sequence. Eggs obtained by induced spawning with hydrogen peroxide from the GIA captive broodstock were stocked at a density of 10 eggs/mL and kept at 23 0.5 BC for 62 h until the formation of the third tubule. Live eggs and larvae were continuously observed on a 24 h basis at a 3400 magnification under transmitted light. At each stages, specific morphological features, illustrated by microscopic photographs, were described, as well as the time required for their apparition. Fertilized eggs diameter was 205 8 mm (mean SD), whereas length and width of larvae ready to undergo metamorphosis were 216.6 5.3 mmand 172 8.8 mm, respectively. Knowledge on the larval morphological development acquired through this study will contribute to the improvement of larval rearing techniques for this abalone species.