ABSTRACT
The knowledge about the effect of salinity on the physiological mechanism of bivalve reproduction is fundamental to improve production strategies in hatcheries. The present work evaluated the influence of different salinity concentrations (15, 20, 25, 30, 35 and 40 gâ L−1) on pre- and post-fertilization development processes in the clam, Anomalocardia flexuosa, oocytes obtained by stripping. Salinity directly interfered with the germinal vesicle breakdown (GVBD) rate and in the cellular stability of unfertilized oocytes. Salinity concentrations between 30 and 35 gâ L−1 provided better percentages of stable GVBD within 120 min, and incubation of oocytes in the salinity range of 30-35 gâ L−1 for a time interval of 80-120 min provided > 80% GVBD. In the post-fertilization analysis, salinity affected the rate of the extrusion of the first and second polar bodies (PB1 and PB2). The release of 50% of the PBs was faster at a salinity of 35 gâ L−1, with an estimated time of 10 min for PB1 and 30 min for PB2. Thus, chromosome manipulation methodologies aiming triploids should be applied at 35 gâ L−1 salinity, with application of post-fertilization shock before 10 min for PB1 retention or before 30 min for PB2 retention.(AU)
Subject(s)
Animals , Female , Cardiidae/chemistry , Fertilization/drug effects , SalinityABSTRACT
Anomalocardia brasiliana is an intertidal filter-feeding clam that can accumulate enterobacteria, such as Escherichia coli, and consequently affect human health. Shellfish depuration is a procedure which reduces microbiological contaminants; however, salinity and depuration time can vary across species to adequately reduce bacteria load. To analyze the effect of salinity on the bioaccumulation and depuration of E. coli by A. brasiliana, this study evaluated salinity and depuration time in animals artificially contaminated with E. coli. Each experimental group of clams were acclimated for 6 hours in a recirculating aquaculture system (RAS) and then exposed to E. coli for 18 hours. Following exposure, clams were then held at one of four salinities (35, 30, 25 e 20) for a period of one of four depuration times (0, 12, 24, 36 and 48h). The highest bioaccumulation of E. coli in A. brasiliana was observed in clams held at salinities of 35, 30 and 25. The greatest reduction of E. coli in A. brasiliana was observed in clams held at 25 for 48 hours. A salinity of 20 showed low bioaccumulation and depuration of E. coli. The results of this study will contribute to developing a protocol for depurating A. brasiliana to mitigate human health concerns.
Anomalocardia brasiliana é um molusco de areia filtrador que habita entremarés, o qual pode acumular enterobactérias como E. coli e, consequentemente, afetar o ser humano. A depuração de moluscos é o procedimento para reduzir a contaminação; para isso, é necessária uma adequada qualidade da água. A fim de analisar o efeito da salinidade na bioacumulação e na depuração de E. coli por A. brasiliana, o presente estudo avaliou quatro salinidades (35, 30, 25 e 20) e quatro tempos de depuração (0, 12, 24, 36 e 48h) em animais contaminados artificialmente com E. coli. Todos os moluscos foram aclimatados por seis horas e posteriormente expostos a E. coli por 18h no sistema de depuração. O experimento de depuração foi realizado em um sistema de recirculação de água (RAS). A maior bioacumulação de E. coli em A. brasiliana foi observada nas salinidades de 35, 30 e 25, e a maior redução de E. coli nos animais foi observada na salinidade de 25, após 48h de depuração. A salinidade de 20 apresentou uma baixa bioacumulação de E. coli. A maior redução de E. coli em A. brasiliana foi observada na salinidade 25 depois de 48h de depuração. Os resultados do presente estudo podem contribuir para o desenvolvimento de um protocolo de depuração para essa espécie.
Subject(s)
Animals , Escherichia coli/isolation & purification , Cardiidae/microbiology , Bioaccumulation , Metabolic Clearance Rate , SalinityABSTRACT
The cockle Cerastoderma edule was exposed to four concentrations (5, 10, 20 and 70 µg L-1) of carbamazepine (CBZ). This anticonvulsant was found to alter the mussel behavior of by reducing its clearance rate (CR). Analysis of CBZ accumulation in tissues of C. edule was carried out using HPLC-UV after 48 or 96 hours of exposure. In addition, an overproduction of H2O2 by the bivalves was detected following exposure to CBZ but nitrite levels remained unchanged. Moreover, superoxide dismutase and catalase activities showed a significant increase in relation to their contact with CBZ. The activity of the biotransformation enzyme gluthatione-S-transferase did not change during exposure. Malondialdehyde (MDA) levels indicating cellular damage, increased when bivalves were exposed to 20 and 70 µg l-1 of carbamazepine for 96 h CBZ. The results also indicate that acetylcholinesterase activity (AChE) was inhibited in all CBZ concentrations during the 48 h exposure period. However, during the 96 h exposure period, AChE was only inhibited at the highest concentration. Further studies are needed now for more exploration of the toxicity of CBZ since it could be bioaccumulable throughout the food web and may affect non-target organisms.
O berbigão Cerastoderma edule foi exposto a quatro concentrações (5, 10, 20 e 70 µg L-1) de carbamazepina (CBZ). Este anticonvulsivante alterou o comportamento do mexilhão, reduzindo sua taxa de depuração (CR). A análise do acúmulo de CBZ nos tecidos de C. edule foi realizada por HPLC-UV após 48 ou 96 horas de exposição. Além disso, uma superprodução de H2O2 pelos bivalves foi detectada após a exposição à CBZ, mas os níveis de nitrito permaneceram inalterados. Além disso, as atividades de superóxido dismutase e catalase apresentaram aumento significativo em relação ao contato com CBZ. A atividade da enzima de biotransformação glutationa-S-transferase não se alterou durante a exposição. Os níveis de malondialdeído (MDA), indicando dano celular, aumentaram quando os bivalves foram expostos a 20 e 70 µg l-1 de carbamazepina por 96 h CBZ. Os resultados também indicam que a atividade da acetilcolinesterase (AChE) foi inibida em todas as concentrações de CBZ durante o período de exposição de 48 horas. No entanto, durante o período de exposição de 96 horas, a AChE foi inibida apenas na concentração mais alta. Mais estudos são necessários agora para uma maior exploração da toxicidade da CBZ, uma vez que pode ser bioacumulável em toda a cadeia alimentar e pode afetar organismos não alvo.
Subject(s)
Animals , Water Pollutants, Chemical/toxicity , Bivalvia , Cardiidae , Carbamazepine/toxicity , Hydrogen PeroxideABSTRACT
The cockle Cerastoderma edule was exposed to four concentrations (5, 10, 20 and 70 μg L-¹) of carbamazepine (CBZ). This anticonvulsant was found to alter the mussel behavior of by reducing its clearance rate (CR). Analysis of CBZ accumulation in tissues of C. edule was carried out using HPLC-UV after 48 or 96 hours of exposure. In addition, an overproduction of H2O2 by the bivalves was detected following exposure to CBZ but nitrite levels remained unchanged. Moreover, superoxide dismutase and catalase activities showed a significant increase in relation to their contact with CBZ. The activity of the biotransformation enzyme gluthatione-S-transferase did not change during exposure. Malondialdehyde (MDA) levels indicating cellular damage, increased when bivalves were exposed to 20 and 70 μg l-¹ of carbamazepine for 96 h CBZ. The results also indicate that acetylcholinesterase activity (AChE) was inhibited in all CBZ concentrations during the 48 h exposure period. However, during the 96 h exposure period, AChE was only inhibited at the highest concentration. Further studies are needed now for more exploration of the toxicity of CBZ since it could be bioaccumulable throughout the food web and may affect non-target organisms.
O berbigão Cerastoderma edule foi exposto a quatro concentrações (5, 10, 20 e 70 μg L-¹) de carbamazepina (CBZ). Este anticonvulsivante alterou o comportamento do mexilhão, reduzindo sua taxa de depuração (CR). A análise do acúmulo de CBZ nos tecidos de C. edule foi realizada por HPLC-UV após 48 ou 96 horas de exposição. Além disso, uma superprodução de H2O2 pelos bivalves foi detectada após a exposição à CBZ, mas os níveis de nitrito permaneceram inalterados. Além disso, as atividades de superóxido dismutase e catalase apresentaram aumento significativo em relação ao contato com CBZ. A atividade da enzima de biotransformação glutationa-S-transferase não se alterou durante a exposição. Os níveis de malondialdeído (MDA), indicando dano celular, aumentaram quando os bivalves foram expostos a 20 e 70 μg l-1 de carbamazepina por 96 h CBZ. Os resultados também indicam que a atividade da acetilcolinesterase (AChE) foi inibida em todas as concentrações de CBZ durante o período de exposição de 48 horas. No entanto, durante o período de exposição de 96 horas, a AChE foi inibida apenas na concentração mais alta. Mais estudos são necessários agora para uma maior exploração da toxicidade da CBZ, uma vez que pode ser bioacumulável em toda a cadeia alimentar e pode afetar organismos não alvo.
Subject(s)
Animals , Carbamazepine/administration & dosage , Carbamazepine/toxicity , Cardiidae/drug effects , Cardiidae/enzymology , Biomarkers/analysisABSTRACT
The cockle Cerastoderma edule was exposed to four concentrations (5, 10, 20 and 70 μg L-¹) of carbamazepine (CBZ). This anticonvulsant was found to alter the mussel behavior of by reducing its clearance rate (CR). Analysis of CBZ accumulation in tissues of C. edule was carried out using HPLC-UV after 48 or 96 hours of exposure. In addition, an overproduction of H2O2 by the bivalves was detected following exposure to CBZ but nitrite levels remained unchanged. Moreover, superoxide dismutase and catalase activities showed a significant increase in relation to their contact with CBZ. The activity of the biotransformation enzyme gluthatione-S-transferase did not change during exposure. Malondialdehyde (MDA) levels indicating cellular damage, increased when bivalves were exposed to 20 and 70 μg l-¹ of carbamazepine for 96 h CBZ. The results also indicate that acetylcholinesterase activity (AChE) was inhibited in all CBZ concentrations during the 48 h exposure period. However, during the 96 h exposure period, AChE was only inhibited at the highest concentration. Further studies are needed now for more exploration of the toxicity of CBZ since it could be bioaccumulable throughout the food web and may affect non-target organisms.(AU)
O berbigão Cerastoderma edule foi exposto a quatro concentrações (5, 10, 20 e 70 μg L-¹) de carbamazepina (CBZ). Este anticonvulsivante alterou o comportamento do mexilhão, reduzindo sua taxa de depuração (CR). A análise do acúmulo de CBZ nos tecidos de C. edule foi realizada por HPLC-UV após 48 ou 96 horas de exposição. Além disso, uma superprodução de H2O2 pelos bivalves foi detectada após a exposição à CBZ, mas os níveis de nitrito permaneceram inalterados. Além disso, as atividades de superóxido dismutase e catalase apresentaram aumento significativo em relação ao contato com CBZ. A atividade da enzima de biotransformação glutationa-S-transferase não se alterou durante a exposição. Os níveis de malondialdeído (MDA), indicando dano celular, aumentaram quando os bivalves foram expostos a 20 e 70 μg l-1 de carbamazepina por 96 h CBZ. Os resultados também indicam que a atividade da acetilcolinesterase (AChE) foi inibida em todas as concentrações de CBZ durante o período de exposição de 48 horas. No entanto, durante o período de exposição de 96 horas, a AChE foi inibida apenas na concentração mais alta. Mais estudos são necessários agora para uma maior exploração da toxicidade da CBZ, uma vez que pode ser bioacumulável em toda a cadeia alimentar e pode afetar organismos não alvo.(AU)
Subject(s)
Animals , Cardiidae/drug effects , Cardiidae/enzymology , Carbamazepine/administration & dosage , Carbamazepine/toxicity , Biomarkers/analysisABSTRACT
The cockle Cerastoderma edule was exposed to four concentrations (5, 10, 20 and 70 µg L-1) of carbamazepine (CBZ). This anticonvulsant was found to alter the mussel behavior of by reducing its clearance rate (CR). Analysis of CBZ accumulation in tissues of C. edule was carried out using HPLC-UV after 48 or 96 hours of exposure. In addition, an overproduction of H2O2 by the bivalves was detected following exposure to CBZ but nitrite levels remained unchanged. Moreover, superoxide dismutase and catalase activities showed a significant increase in relation to their contact with CBZ. The activity of the biotransformation enzyme gluthatione-S-transferase did not change during exposure. Malondialdehyde (MDA) levels indicating cellular damage, increased when bivalves were exposed to 20 and 70 µg l-1 of carbamazepine for 96 h CBZ. The results also indicate that acetylcholinesterase activity (AChE) was inhibited in all CBZ concentrations during the 48 h exposure period. However, during the 96 h exposure period, AChE was only inhibited at the highest concentration. Further studies are needed now for more exploration of the toxicity of CBZ since it could be bioaccumulable throughout the food web and may affect non-target organisms.
Subject(s)
Bivalvia , Cardiidae , Water Pollutants, Chemical , Animals , Carbamazepine/toxicity , Hydrogen Peroxide , Water Pollutants, Chemical/toxicityABSTRACT
The ecological and ethnological aspects of the harvesting of the cockle, Leukoma pectorina (Bivalvia: Veneridae), were investigated on Algodoal-Maiandeua Island, on the Amazon coast of Brazil. Ethnobiological data were collected through informal conversations, semi-structured interviews, and observations of the harvesting and processing of bivalves on the island. Following the ethnobiology study, the cockle beds were surveyed to evaluate the density of L. pectorina, body size and the meat yield of the cockles in the months of dry and rainy seasons. In the study area, cockling is a manual and artisanal activity, and L. pectorina is typically harvested by mothers with little formal education. The cocklers make their own tools, cockles are prepared in the family environment, and the majority of the catch is sold to commercial establishments on the island. Cockling is a sporadic activity used to complement the family income, and is more common during the dry season, when tourism increases on Algodoal-Maiandeua Island. The cockles are also larger and population density is higher during this season, and the cocklers themselves recognize this period as providing the most productive harvest. These findings reinforce the value of traditional knowledge for both scientific research and the planning of the management of coastal fishery resources.
Subject(s)
Cardiidae , Fisheries , Animals , Brazil , KnowledgeABSTRACT
A type of dredge was introduced as fishing gear along the extractive bank of Mangue Seco - PE from which the largest annual catch of Anomalocardia flexuosa in the world is extracted. This study was carried out with the objective of estimating the selectivity of the new fishing gear and quantitatively evaluating the length classes most compromised by the catches, especially considering 20 mm as the reference value. Specimens larger than this size are most likely to be mature. For the selectivity estimation, the methodology using codends (16 or 20 mm) and small meshed cover (2 mm) was used. To estimate the selectivity parameters, a logistic regression and the Bayesian approach were used. The transition between the state in which the specimen is invulnerable to the fishing gear and vulnerable occurs between 10 and 18 mm, using a 16 mm mesh, and using a 20 mm mesh, this transition is between 14 and 20 mm. Dredgers with 16 mm and 20 mm mesh compromise a large proportion of specimens smaller than 20 mm. If the intention is to protect this part of the population, measures such as total restriction of the 16 mm mesh and use of the 20 mm mesh should be necessary only in the months of less catching incidences, or increasing the mesh to 25 mm.(AU)
Um tipo de draga foi introduzido como arte de pesca no banco extrativista de Mangue Seco - PE de onde se extrai a maior captura anual de Anomalocardia flexuosa do mundo. Este trabalho foi realizado com objetivo de estimar a seletividade do novo petrecho de pesca e avaliar quantitativamente quais são as classes de comprimento mais penalizadas nas capturas, tendo especialmente como referencial o valor de 20 mm. Exemplares maiores que esse tamanho tem elevada probabilidade de estarem maturos. Para estimativa da seletividade foi utilizado o método com uso de saco (16 ou 20 mm) e sobresaco (2 mm). Para estimativa dos parâmetros de seletividade foi utilizada regressão logística e abordagem bayesiana. A transição entre o estado em que o exemplar é invulnerável à arte de pesca e em que o mesmo seria quase com certeza capturado ocorre para malha de 16 mm entre 10 e 18 mm, enquanto para malha de 20 mm essa transição se dá entre 14 e 20 mm. As dragas com malha de 16 e 20 mm penalizam uma proporção grande de exemplares menores que 20 mm. Se a intenção é proteger essa parcela da população, seriam necessárias medidas como a restrição total da malha de 16 mm e uso da malha de 20 mm somente nos meses de menor incidência de recrutamento, ou o aumento da malha para 25 mm.(AU)
Subject(s)
Fisheries , Mollusca , Dredges , CardiidaeABSTRACT
Anomalocardia brasiliana post-larvae were cultured for 28 days to evaluate the effect of stocking density on their growth and survival rate. Three stocking densities were tested 40, 80 and 160 post-larvae cm-2, in experimental units (2-L) with static cultivation system and total water renewal at each 48 hours. The experimental design was completely randomized with three treatments and three repetitions each. Stocking density of 40 post-larvae cm-2 reached 1 mm length within 24 days, while only 18% of the post-larvae at density of 80 post-larvae cm-2 reached 1 mm length in the same time. The density of 40 post-larvae cm-2 had the highest specific growth rate, 4.98±0.08% day-1. The survival rates of post-larvae at lower densities were significantly higher (53.24±4.60% and 52.95±3.32%, on 40 and 80 post-larvae cm-2, respectively) compared to higher stocking density (31.54±0.70%). In the cultivation of A. brasiliana post-larvae, stocking density must be managed during growth. The density of 160 post-larvae cm-2 can only be used until the post-larvae reach 600μm in length, then they should be at 40 post-larvae cm-2 density to keep the maximum daily growth rate.(AU)
Pós-larvas de Anomalocardia brasiliana foram cultivadas por 28 dias para avaliar o efeito da densidade de estocagem no crescimento e taxa de sobrevivência. Três densidades de estocagem foram testadas: 40, 80 e 160 pós-larvas cm-2, em unidades experimentais (2 L) com sistema de cultivo estatístico e renovação total de água a cada 48 h. O delineamento experimental foi inteiramente casualizado com três tratamentos em triplicata. A densidade de estocagem com 40 pós-larvas cm-2 alcançou 1 mm de comprimento após 24 dias, enquanto apenas 18% das pós-larvas estocadas a 80 pós-larvas cm-2 atingiram 1 mm de comprimento no mesmo período. A densidade de 40 pós-larvas cm-2 apresentou a maior taxa de crescimento específico 4,98±0,08% dia-1. As taxas de sobrevivência de pós-larvas em baixas densidades foram significativamente maiores (53,24 ± 4,60% e 52,95 ± 3,32%, em 40 e 80 pós-larvas cm-2, respectivamente) em comparação com a maior densidade de estocagem (31,54 ± 0,70%). Os resultados sugerem que na criação de pós-larvas de A. brasiliana, a densidade populacional deve ser ajustada durante o crescimento. A densidade de 160 pós-larvas cm-2 só pode ser usada até que as pós-larvas atinjam o comprimento de 600µm; em seguida deve ser alterada para a densidade de 40 pós-larvas cm-2 para manter a taxa máxima de crescimento diário.(AU)
Subject(s)
Animals , Crowding , Bivalvia/growth & development , Aquaculture/methods , Microalgae , Cardiidae/growth & development , Population DensityABSTRACT
Anomalocardia brasiliana post-larvae were cultured for 28 days to evaluate the effect of stocking density on their growth and survival rate. Three stocking densities were tested 40, 80 and 160 post-larvae cm-2, in experimental units (2-L) with static cultivation system and total water renewal at each 48 hours. The experimental design was completely randomized with three treatments and three repetitions each. Stocking density of 40 post-larvae cm-2 reached 1 mm length within 24 days, while only 18% of the post-larvae at density of 80 post-larvae cm-2 reached 1 mm length in the same time. The density of 40 post-larvae cm-2 had the highest specific growth rate, 4.98±0.08% day-1. The survival rates of post-larvae at lower densities were significantly higher (53.24±4.60% and 52.95±3.32%, on 40 and 80 post-larvae cm-2, respectively) compared to higher stocking density (31.54±0.70%). In the cultivation of A. brasiliana post-larvae, stocking density must be managed during growth. The density of 160 post-larvae cm-2 can only be used until the post-larvae reach 600μm in length, then they should be at 40 post-larvae cm-2 density to keep the maximum daily growth rate.
Pós-larvas de Anomalocardia brasiliana foram cultivadas por 28 dias para avaliar o efeito da densidade de estocagem no crescimento e taxa de sobrevivência. Três densidades de estocagem foram testadas: 40, 80 e 160 pós-larvas cm-2, em unidades experimentais (2 L) com sistema de cultivo estatístico e renovação total de água a cada 48 h. O delineamento experimental foi inteiramente casualizado com três tratamentos em triplicata. A densidade de estocagem com 40 pós-larvas cm-2 alcançou 1 mm de comprimento após 24 dias, enquanto apenas 18% das pós-larvas estocadas a 80 pós-larvas cm-2 atingiram 1 mm de comprimento no mesmo período. A densidade de 40 pós-larvas cm-2 apresentou a maior taxa de crescimento específico 4,98±0,08% dia-1. As taxas de sobrevivência de pós-larvas em baixas densidades foram significativamente maiores (53,24 ± 4,60% e 52,95 ± 3,32%, em 40 e 80 pós-larvas cm-2, respectivamente) em comparação com a maior densidade de estocagem (31,54 ± 0,70%). Os resultados sugerem que na criação de pós-larvas de A. brasiliana, a densidade populacional deve ser ajustada durante o crescimento. A densidade de 160 pós-larvas cm-2 só pode ser usada até que as pós-larvas atinjam o comprimento de 600µm; em seguida deve ser alterada para a densidade de 40 pós-larvas cm-2 para manter a taxa máxima de crescimento diário.
Subject(s)
Animals , Crowding , Aquaculture/methods , Bivalvia/growth & development , Cardiidae/growth & development , Microalgae , Population DensityABSTRACT
The Andean genus Rhaucus Simon 1879 is revised. Five valid species are recognized, including Rhaucus florezi sp. nov. The following nomenclatural acts are proposed. At genus level: Megarhaucus Mello-Leitão, 1941, Neorhaucus Pickard-Cambridge, 1905 and Pararhaucus Pickard-Cambridge, 1905 are considered junior subjective synonyms of Rhaucus. At species level: Neorhaucus aurolineatus Pickard-Cambridge, 1905 is considered a junior subjective synonym of Rhaucus vulneratus Simon, 1879; Rhaucus (Rhaucus) tristis Sørensen, 1932, Rhaucus (Rhaucus) muticus Sørensen, 1932 and Pararhaucus obscurus Pickard-Cambridge, 1905 are considered junior subjective synonyms of Rhaucus quinquelineatus Simon, 1879 (the latter combination is restored from current combination Flirtea quinquelineata); Flirtea paucimaculata Roewer, 1963, Rhaucus (Rhaucus) geographicus Sørensen, 1932, Metarhaucus reticulatus Roewer, 1912 and Metarhaucus fuscus Pickard-Cambridge, 1905 are considered junior subjective synonyms of Erginus serripes Simon, 1879 (that is here combined as Rhaucus serripes comb. rest.). Megarhaucus robustus Mello-Leitão, 1941 is newly combined as Rhaucus robustus (Mello-Leitão, 1941) comb. nov. Distribution maps of the species are provided. The new term multicapitate apophysis (mca) is introduced here for a special type of apophysis on coxa IV of males.
Subject(s)
Arachnida , Animal Distribution , Animal Structures , Animals , Body Size , Cardiidae , Male , Organ Size , SpidersABSTRACT
High exploitation of natural stocks and changes in the environment has affected the populations of the native clam Anomalocardia brasiliana, becoming necessary the development of technologies for seeds production in laboratory. Aiming to contribute to the seeds production technology of the native clam A. brasiliana, the density and diet of larval cultivation and time for larviculture was evaluated. In the densities 10 and 30 larvae mL-1 were obtained the better survival of A. brasiliana larvae. Evaluating the larviculture time for settlement, the larvae can be transferred with five days of culture and maintained in the settlement in a density of 25 larvae cm-2. Additionally, bialgais diets with the microalgaes Chaetoceros muelleri and Nannocholopsis oculata, and C. muelleri and Pavlova lutheri showed better growth and survival of A. brasiliana larvae.(AU)
A elevada extração em estoques naturais e as alterações no meio ambiente têm comprometido as populações do molusco de areia Anomalocardia brasiliana, tornando cada vez mais necessário o desenvolvimento de tecnologias para a produção de sementes desse bivalve em laboratório. Com o objetivo de contribuir com a tecnologia de produção de sementes do berbigão em ambiente controlado, foram avaliadas a densidade e a dieta no cultivo larval e o tempo de larvicultura de A. brasiliana. Nas densidades de 10 e 30 larvas mL-1 foram obtidos os melhores valores de sobrevivência de larvas de A. brasiliana. Avaliando o tempo de larvicultura para assentamento, conclui-se que as larvas podem ser transferidas com cinco dias de cultivo e mantidas no assentamento na densidade de 25 larvas cm-2. Adicionalmente, larvas de A. brasiliana, alimentadas com dietas bialgais com as microalgas Chaetoceros muelleri e Nannocholopsis oculata e C. muelleri e Pavlova lutheri apresentaram melhores resultados de crescimento e sobrevivência.(AU)
Subject(s)
Animals , Larva/growth & development , Bivalvia/growth & development , Survival Analysis , Cardiidae , Population Density , Laboratory TestABSTRACT
High exploitation of natural stocks and changes in the environment has affected the populations of the native clam Anomalocardia brasiliana, becoming necessary the development of technologies for seeds production in laboratory. Aiming to contribute to the seeds production technology of the native clam A. brasiliana, the density and diet of larval cultivation and time for larviculture was evaluated. In the densities 10 and 30 larvae mL-1 were obtained the better survival of A. brasiliana larvae. Evaluating the larviculture time for settlement, the larvae can be transferred with five days of culture and maintained in the settlement in a density of 25 larvae cm-2. Additionally, bialgais diets with the microalgaes Chaetoceros muelleri and Nannocholopsis oculata, and C. muelleri and Pavlova lutheri showed better growth and survival of A. brasiliana larvae.
A elevada extração em estoques naturais e as alterações no meio ambiente têm comprometido as populações do molusco de areia Anomalocardia brasiliana, tornando cada vez mais necessário o desenvolvimento de tecnologias para a produção de sementes desse bivalve em laboratório. Com o objetivo de contribuir com a tecnologia de produção de sementes do berbigão em ambiente controlado, foram avaliadas a densidade e a dieta no cultivo larval e o tempo de larvicultura de A. brasiliana. Nas densidades de 10 e 30 larvas mL-1 foram obtidos os melhores valores de sobrevivência de larvas de A. brasiliana. Avaliando o tempo de larvicultura para assentamento, conclui-se que as larvas podem ser transferidas com cinco dias de cultivo e mantidas no assentamento na densidade de 25 larvas cm-2. Adicionalmente, larvas de A. brasiliana, alimentadas com dietas bialgais com as microalgas Chaetoceros muelleri e Nannocholopsis oculata e C. muelleri e Pavlova lutheri apresentaram melhores resultados de crescimento e sobrevivência.
Subject(s)
Animals , Survival Analysis , Bivalvia/growth & development , Cardiidae , Larva/growth & development , Population Density , Laboratory TestABSTRACT
Based on the study of available types and extant collections, this paper provides a systematic revision of the living species of Carditoidea occurring in the Magellan and Perú-Chile Provinces. Out of the 19 nominal species reported for the area, eight species are recognized as valid: Cyclocardia compressa, C. spurca, C. thouarsii, C. velutina, Carditella naviformis, C. semen, C. tegulata and Carditopsis flabellum. Other eight nominal species are regarded as synonyms: Cardita magellanica of Cyclocardia velutina; Carditella pallida of C. tegulata; Cardita australis and Actinobolus philippi of Carditella naviformis; Cardium pygmaeum of Carditella semen; Cardita paeteliana of Cyclocardia spurca; Carditella pallida duodecimcostata of Carditopsis flabellum; and Cardita congelascens of Cyclocardia thouarsii. Furthermore, Cardita malvinae and Cardium parvulum are nomina dubia, and the occurrence of Carditella exulata in Magellanic waters is doubtful.
Subject(s)
Bivalvia/anatomy & histology , Bivalvia/classification , Animal Distribution , Animals , Cardiidae/anatomy & histology , Cardiidae/classification , South America , Species SpecificityABSTRACT
Blood cockles are among the most economically important brackish water invertebrates found in Malaysia. However, our knowledge of blood cockle phylogeny and systematics is rudimentary, especially for the species Tegillarca granosa. It is unclear, for instance, whether the cockles occurring on the west coast of peninsular Malaysia constitute a single species, or multiple, phylogenetically distinct species. We performed the first DNA molecular phylogenetic analysis of T. granosa to distinguish it from other related species found in other parts of the world and to create a DNA database for the species. An approximately 585-nucleotide fragment of the mitochondrial DNA (cytochrome oxidase I, COI) was sequenced for 150 individual cockles, representing 10 populations: three from the north, four from the central part and three from the southern part of peninsular Malaysia. Phylogenetic analyses of the resulting dataset yielded tree topologies that not only showed the relationship between T. granosa and its closest relatives but its position in the evolutionary tree. Three mitochondrial clades were evident, each containing an individual genus. Using the mutation rate of the COI gene, the divergence time between T. granosa and its closest related species was estimated to be 460 thousand years ago. This study provides a phylogenetic framework for this ecologically prominent and commercially important cockle species.
Subject(s)
Cardiidae/genetics , Phylogeny , Animals , Cardiidae/classification , DNA/genetics , Humans , MalaysiaABSTRACT
We examined genetic variation in blood cockles in an effort to obtain information useful for the sustainability, management, and the stability of this species as a major commodity in the fisheries sector. Ten populations of cockles were sampled from the north to the south of the west coast of peninsular Malaysia. The cockles were collected in collaboration with the Fisheries Research Institute, Penang. The population genetic analysis of the cockles were studied via RAPD-PCR and mtDNA sequencing. Three hundred individuals were analyzed with RAPD-PCR experiments. High gene diversity over all loci was observed (Shannon index = 0.549 ± 0.056 and Nei's gene diversity = 0.4852 ± 0.0430 among 35 loci). The second method, mtDNA sequencing, was employed to complement the information obtained from RAPD-PCR. The gene selected for mtDNA sequencing was cytochrome c oxidase I (COI). One hundred and fifty individuals were sequenced, yielding a partial gene of 585 bp. Statistical analysis showed homogeneity in general but did reveal some degree of variability between the populations in Johor and the rest of the populations. The Mantel test showed a positive but nonsignificant correlation between geographic and genetic distances (r = 0.2710, P = 0.622), as in the RAPD analysis. We propose that the homogeneity between distant populations is caused by two factors: 1) the translocation of the spats; 2) larvae are carried by current movement from the north of the peninsula to the south. The different genetic composition found in Johor could be due to pollution, mutagenic substances or physical factors such as the depth of the water column. This population genetic study is the first for this species in peninsular Malaysia. The data from this study have important implications for fishery management, conservation of blood cockles and translocation policies for aquaculture and stock enhancement programs.
Subject(s)
Cardiidae/genetics , Conservation of Natural Resources , Genetic Markers , Animals , Base Sequence , DNA Primers , DNA, Mitochondrial/genetics , Polymerase Chain Reaction , Random Amplified Polymorphic DNA TechniqueABSTRACT
Antimicrobianos de origem natural são alternativas eficazes e econômicas, pois são obtidos a partir das plantas aromáticas e especiarias ricas em óleos essenciais caracterizados por uma notável atividade antimicrobiana, e por esta razão, seus produtos derivados podem ser usados para retardar ou inibir a multiplicação microbiana. O objetivo deste estudo foi avaliar a atividade antibacteriana dos óleos essenciais de cravo, limão, orégano e alho sobre as cepas de Staphylococcus aureus e Escherichia coli isolados do vôngole (Anomalocardia brasiliana) e cepas padrão ATCC (American Type Culture Collection): Escherichia coli, Staphylococcus aureus e Salmonella cholerasuis, através da técnica de difusão de disco e em seguida a determinação da Concentração Inibitória Mínima (CIM). Neste estudo observou-se que o óleo essencial de alho apresentou atividade antibacteriana frente o S. aureus e a S. cholerasuis; já os óleos de cravo e orégano apresentaram atividade frente a todas as bactérias analisadas, no entanto o óleo de orégano apresentou maiores halos de inibição bacteriana, 26,7mm e 29,3mm para as cepas de E. coli e S. aureus, respectivamente. O óleo essencial de limão não demonstrou atividade antibacteriana. Desta forma os óleos essenciais de cravo e orégano demonstraram as melhores atividades antibacterianas e assim apresentam-se como óleos favoráveis para a aplicação em alimentos.
Natural preservative substances are an efficient and economic alternative, because the aromatical plants and rich spices in essential oils characterized by a notable are gotten from antimicrobial activity, and for this reason, its derived products can be used to delay or to inhibit the growth of microorganisms. The objective of this study was to evaluate the antibacterial activity of essential oils of clove, limon, oregano (Origanum vulgare ssp. Hirtum) and garlic several species of bacteria like Staphylococcus aureus and Escherichia coli isolated of vongole (Anomalocardia Brasiliana) and bacteria standard ATCC (American Type Culture Collection): Escherichia coli, Staphylococcus aureus and Salmonella cholerasuis, through diffusion test and after it was determinate the Minimum Inhibitory Concentration (MIC). In this study it was observed that the garlic essential oil presented antibacterial activity front the S. aureus and the S. cholerasuis.; already the oils of clove and oregano (Origanum vulgare ssp. Hirtum) had presented activity front to all the analyzed bacteria, however the oregano oil presented the bigger bacterial inhibition, 26.7mm e 29,3mm for E. coli e S. aureus respectively. The essential oil of lemon did not demonstrate antibacterial activity. In such a way the oregano and clove essential oils that they had presented antibacterial activity appeared to be the most preferable agent for future research.
Subject(s)
In Vitro Techniques , Oils, Volatile , Cardiidae/microbiology , Anti-Infective AgentsABSTRACT
The consumption of oysters and cockles, which are usually eaten raw or lightly-cooked, can cause outbreaks of human diseases, especially if these shellfish are harvested from polluted areas. In Brazil data about the occurrence of pathogens, like hepatitis A virus, in shellfish have been reported but research on natural contamination for pathogenic protozoa is still non-existent. Cryptosporidium oocyst contamination of oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) was evaluated during two different periods in a coastal area from São Paulo, Brazil. From June to November 2005, and from July to December 2006, 180 mollusks were harvested for tissue examination. The gills and gastrointestinal tract (n = 36 pools) were carefully extracted from the animals and homogenized in a tissue homogenizer by adding surfactant Tween 80 (0.1%). Immunofluorescence assays were performed and Cryptosporidium oocysts were detected in 50.0% of gill pools of cockles and 10.0% of gill pools of oysters. In order to evaluate seawater quality in shellfish growing areas, total levels of thermotolerant coliforms, Escherichia coli and enterococci were determined. This is the first time that Cryptosporidium oocysts were found in shellfish from the coastal region of Brazil, and to the best of our knowledge it is also the first report in Latin America and the case might be of public health importance, reflecting the extension of the contamination on seafood, requiring a need for quality control standards.
Subject(s)
Cardiidae/parasitology , Cryptosporidium/isolation & purification , Ostreidae/parasitology , Public Health , Seawater/parasitology , Animals , Brazil , Fluorescent Antibody Technique , Oocysts/parasitology , Seasons , Water MicrobiologyABSTRACT
A new 23-collar-spined cercaria and metacercaria are described from intertidal molluscs of the coast of New Zealand. The new cercaria found emerging from the mud snails Zeacumantus subcarinatus (Sowerby) (Prosobranchia: Batillariidae) is characterized mainly by the number and arrangement of the cephalic glands, the size of the suckers, and the size and number of the collar spines. The cercaria encysts in the cockle Austrovenus stutchburyi (Wood) (Bivalvia: Veneridae) which lives in sympatry with the first intermediate host throughout New Zealand. Laboratory infections of cockles by cercariae from naturally infected snails resulted in metacercariae identical to those found in naturally infected cockles. The main features of the cercaria and metacercaria are the presence of a reniform collar with 23 spines, two pairs of small cephalic glands at the oral sucker level, another two pairs of much longer ones posterior to the pharynx, and the excretory vesicle Y-shaped with the main collecting canals extending to the anterior level of the ventral sucker. Each of the main collecting canals had 10-11 pairs of bilateral diverticula between the anterior edge of the ventral sucker and anterior body end. A brief discussion of its possible life cycle and ecology is also provided.