Research advances in bioactivity of oyster peptides / 药学实践杂志

Functional peptides refer to peptides that are beneficial to life activities or have special physiological activities, also known as bioactive peptides. Oyster is rich in protein and is a good material for developing bioactive peptides, which has great potential as a functional food and great application value in pharmaceutical and medical industry. With the development of modern biotechnology and medical technology, the method innovation of oyster peptide preparation，the absorptivity and biological activity of oyster peptide have been enhanced significantly, which lead to deep recognition of the biological function of oyster peptide and offer the boarder application prospect. The researches on the diversification activities of oyster peptides were summarized in this review, which provided clues and ideas for the development of the oyster peptide applications.

In vitro ?-amylase and ?-glucosidase inhibitory potential of Pleurotus ostreatus cv. Florida extract

Pleurotus ostreatus cv. Florida is one of the widely used edible mushroom. The polysaccharides from this mushrooms have been studied for antidiabetic potential; however, no efforts have been made to explore the potential of this mushroom to influence carbohydrate metabolizing enzymes viz. ?-amylase and ?-glucosidase. The present work was undertaken to investigate the inhibitory potential of Pleurotus ostreatus cv. Florida on enzymes ?-amylase and ?-glucosidase. Several concentrations of extracts were used to study inhibition of enzymatic activity of ?-amylase and ?-glucosidase. A dose dependent inhibitory effect on enzymes was observed. The current study, for the first time, uncovered ?-amylase and ?-glucosidase inhibitory potential of Pleurotus ostreatus cv. Florida. The study could be helpful to isolate and characterize compounds responsible for it.

Dose-dependent effect of Scolymus hispanicus L. (sevketibostan) on ethylene glycol-induced kidney stone disease in rats

Kidney stone, also known as calcium oxalate nephrolithiasis, is one of the most common diseases worldwide. Calculi usually forms when urine becomes supersaturated with particular calcium salts such as calcium oxalate. In the present study, we investigated the ameliorative potential of the root extract of the Common golden thistle, Scolymus hispanicus L. (SH) on rats with ethylene glycol (EG) induced kidney stone disease. Sprague-Dawley rats, each weighing 250-300 g, were divided into three groups (n=6 per group): (i) Control (C); (ii) EG; and (iii) EG+SH. To induce nephrolithiasis, the rats received 1% of EG with drinking water, while the C group received normal drinking water during the study. SH extract 2 g/kg was added to the treatment from the 4th week onwards in EG+SH group. At the end of each experiment, rats were decapacitated and serum levels of calcium, magnesium, phosphorus, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were assessed in all groups at 0, 4, and 8 weeks. Oxalic acid and creatininelevels were measured in urine samples collected at 24 h in metabolic cages. Renal tissues were evaluated histopathologically at the end of the experiment. After 8 weeks, serum creatinine levels were found decreased in the SH group while increased in the EG group. Serum magnesium and AST levels were also found decreased in the EG group, however, SH treatment reversed these values. The SH treatment also increased urinary oxalic acid levels. When the kidney tissue of EG group was examined, there was a high level of crystal/stone, especially in the renal cortex. In kidney tissues of the SH group, only small amounts of crystal/stone were observed. Our experimental findings have demonstrated the ameliorative potential of the aqueous extracts of S. hispanicus roots and shells on EG-induced in the kidney stones in rats. Isolation of active compounds of SH would be desirable to understand the biochemical mechanism behind the process better.

Biological control of incrusting organisms and sediments in Chilean oyster cultures / Controle biológico dos organismos incrustáveis e sedimentos em culturas de ostras Chilenas

The oyster culture has the incrusting organism as problem for production, in this context, it evaluated as biological control against incrusting organism and sediments the introduction of gastropod Tegula atra (Lesson, 1830) in Chilean oysters (Triostrea chilensis Phillippi, 1844) cultures in conditions of starvation presence and absence located in floating cages and bottom cultures. The predation and mechanic effect on T. atra grazing generated a decreasing in seven days of 19.8% and 13.7% of incrusting organisms in cage culture and bottom sediments by effects of gastropods without starvation respectively. Whereas it had a decrease of 12.6% and 11.4% of incrusting organisms in cage culture and bottom sediments by effects of gastropods with starvation respectively. The incrusting organism removed were mainly algae, colonial ascidia, polychaeta, bryozoan and small crustaceans.

A cultura da ostra tem como problema de produção o organismo incrustante, neste contexto, avaliou como controle biológico contra organismos incrustantes e sedimentos a introdução do gastrópode Tegula atra (Lesson, 1830) em culturas de ostras chilenas (Triostrea chilensis Phillippi, 1844) em condições de presença e ausência de fome, localizadas em gaiolas flutuantes e culturas de fundo. A predação e o efeito mecânico no pastejo de T. atra geraram uma diminuição em sete dias de 19,8% e 13,7% dos organismos incrustantes na cultura em gaiola e nos sedimentos de fundo, por efeito de gastrópodes sem fome, respectivamente. Considerando que houve decréscimo de 12,6% e 11,4% dos organismos incrustantes na cultura em gaiola e nos sedimentos de fundo pelos efeitos dos gastrópodes com fome respectivamente. Os organismos incrustantes removidos eram principalmente algas, ascídias coloniais, poliquetas, briozoários e pequenos crustáceos.

Biological control of incrusting organisms and sediments in Chilean oyster cultures / Controle biológico dos organismos incrustáveis e sedimentos em culturas de ostras Chilenas

The oyster culture has the incrusting organism as problem for production, in this context, it evaluated as biological control against incrusting organism and sediments the introduction of gastropod Tegula atra (Lesson, 1830) in Chilean oysters (Triostrea chilensis Phillippi, 1844) cultures in conditions of starvation presence and absence located in floating cages and bottom cultures. The predation and mechanic effect on T. atra grazing generated a decreasing in seven days of 19.8% and 13.7% of incrusting organisms in cage culture and bottom sediments by effects of gastropods without starvation respectively. Whereas it had a decrease of 12.6% and 11.4% of incrusting organisms in cage culture and bottom sediments by effects of gastropods with starvation respectively. The incrusting organism removed were mainly algae, colonial ascidia, polychaeta, bryozoan and small crustaceans.

A cultura da ostra tem como problema de produção o organismo incrustante, neste contexto, avaliou como controle biológico contra organismos incrustantes e sedimentos a introdução do gastrópode Tegula atra (Lesson, 1830) em culturas de ostras chilenas (Triostrea chilensis Phillippi, 1844) em condições de presença e ausência de fome, localizadas em gaiolas flutuantes e culturas de fundo. A predação e o efeito mecânico no pastejo de T. atra geraram uma diminuição em sete dias de 19,8% e 13,7% dos organismos incrustantes na cultura em gaiola e nos sedimentos de fundo, por efeito de gastrópodes sem fome, respectivamente. Considerando que houve decréscimo de 12,6% e 11,4% dos organismos incrustantes na cultura em gaiola e nos sedimentos de fundo pelos efeitos dos gastrópodes com fome respectivamente. Os organismos incrustantes removidos eram principalmente algas, ascídias coloniais, poliquetas, briozoários e pequenos crustáceos.

Biological control of incrusting organisms and sediments in Chilean oyster cultures

Abstract The oyster culture has the incrusting organism as problem for production, in this context, it evaluated as biological control against incrusting organism and sediments the introduction of gastropod Tegula atra (Lesson, 1830) in Chilean oysters (Triostrea chilensis Phillippi, 1844) cultures in conditions of starvation presence and absence located in floating cages and bottom cultures. The predation and mechanic effect on T. atra grazing generated a decreasing in seven days of 19.8% and 13.7% of incrusting organisms in cage culture and bottom sediments by effects of gastropods without starvation respectively. Whereas it had a decrease of 12.6% and 11.4% of incrusting organisms in cage culture and bottom sediments by effects of gastropods with starvation respectively. The incrusting organism removed were mainly algae, colonial ascidia, polychaeta, bryozoan and small crustaceans.

Resumo A cultura da ostra tem como problema de produção o organismo incrustante, neste contexto, avaliou como controle biológico contra organismos incrustantes e sedimentos a introdução do gastrópode Tegula atra (Lesson, 1830) em culturas de ostras chilenas (Triostrea chilensis Phillippi, 1844) em condições de presença e ausência de fome, localizadas em gaiolas flutuantes e culturas de fundo. A predação e o efeito mecânico no pastejo de T. atra geraram uma diminuição em sete dias de 19,8% e 13,7% dos organismos incrustantes na cultura em gaiola e nos sedimentos de fundo, por efeito de gastrópodes sem fome, respectivamente. Considerando que houve decréscimo de 12,6% e 11,4% dos organismos incrustantes na cultura em gaiola e nos sedimentos de fundo pelos efeitos dos gastrópodes com fome respectivamente. Os organismos incrustantes removidos eram principalmente algas, ascídias coloniais, poliquetas, briozoários e pequenos crustáceos.

Particle size of oyster shell meal and calcium: phosphorus ratios in broiler diets / Efeito do tamanho de partícula da farinha de ostras e relações cálcio: fósforo em dietas para frangos de corte

The effects of Ca:P total ratio and particle size of oyster shell meal (OSM) were evaluated in broiler diets. In Experiment 1, 800 broilers (22-42 days old) were distributed in a 2×2 factorial design, with two Ca:P ratios (1.7 and 2.0:1) and two OSM particle sizes (coarse = 1,354 µm and fine = 428 µm), totaling four treatments with 10 repetitions with 20 broilers. Feed intake, weight gain, and feed conversion ratio were calculated. In Experiment 2, 1,280 broilers were distributed in a 2×2×2 factorial design (1.7 and 2.0:1 Ca:P ratios; coarse and fine OSM; male and female broilers), with eight treatments and 16 repetitions with 10 broilers. Apparent metabolizability of dry matter, Ca, P, and apparent metabolizable energy (AME), as well as bone resistance, bone weight, ash, Ca, and P content in the tibia were assessed. Growth performance was not affected (P > 0.05). Coarse OSM increased tibia Ca content in male broilers (P < 0.001), and higher Ca:P ratio improved bone ash and bone resistance in both sexes (P < 0.001), but reduced P content in male broilers (P < 0.05); male broilers displayed heavier bones with higher ash content than females (P < 0.05). Metabolizability of Ca was improved with coarse OSM (P < 0.05); whereas metabolizability of DM, P, and AME was not affected (P > 0.05). In conclusion, diets with a Ca:P total ratio of 2.0:1 containing coarser OSM improved bone mineral composition, particularly in male broilers, and coarse OSM improved the metabolizability of Ca in broilers regardless of the Ca:P total ratio or broiler sex.

Dois experimentos foram conduzidos para avaliar os efeitos do tamanho de partícula da farinha de ostras (FO) e relação Ca:P total em dietas para frangos de corte. No primeiro experimento, 800 frangos (22 a 42 dias) foram distribuídos em um delineamento fatorial 2x2: 2 relações Ca:P (1,7 e 2,0:1) e dois tamanhos de partícula da FO (grossa = 1354 µm e fina = 428 µm), totalizando quatro tratamentos com 10 repetições de 20 aves. O consumo de ração, o ganho de peso e a conversão alimentar foram calculados. No segundo experimento, 1.280 frangos foram distribuídos em um fatorial 2x2x2 (relações Ca:P 1,7 e 2,0:1; FO grossa e fina; aves machos e fêmeas) com oito tratamentos e 16 repetições de 10 aves. Foram avaliados: metabolizabilidade aparente da matéria seca, Ca e P, energia metabolizável aparente (EMA), peso e resistência óssea, conteúdo de cinzas, Ca e P na tíbia. As variáveis de desempenho não foram afetadas (P > 0,05). O uso de FO grossa aumentou o conteúdo de Ca na tíbia de frangos machos (P < 0,001), e a relação Ca:P de 2,0:1 aumentou o conteúdo de cinzas e aprimorou resistência óssea em ambos os sexos (P < 0,001), porém reduziu P na tíbia dos machos (P < 0,05); frangos machos também tiveram ossos mais pesados e maior conteúdo de cinzas do que fêmeas (P < 0,05). A metabolizabilidade de Ca foi melhorada com FO grossa, enquanto a metabolizabilidade da matéria seca, P, e EMA não foram afetadas (P > 0,05). Conclui-se que as dietas com relação Ca:P de 2,0:1 e com FO grossa resultaram em melhor composição mineral óssea - particularmente em frangos machos - e a FO grossa melhorou a metabolizabilidade de Ca independentemente da relação Ca:P ou do gênero das aves.

Growth and survival of the native oyster Crassostrea gasar cultured under different stocking densities in two grow-out systems in tropical climate / [Crescimento e sobrevivência da ostra nativa Crassostrea gasar cultivada em diferentes densidades em dois sistemas em clima tropical]

Survival and growth of the native oyster Crassostrea gasar along the juvenile and adult phases were evaluated in three different stocking densities [low (D), medium (2D) and high (3D)] and in two grow-out systems (fixed and floating system). The fixed system consisted of a rack made with PVC, fixed from the bottom with wood sticks. The floating system consisted of floating bags suspended by a rack made with PVC and maintained submerged from the seawater surface by eight floats. Survival and shell height of oysters cultured after 30, 60 and 90 days were registered in each phase and in each grow-out system. Results showed that the grow-out system did not affect survival and growth of C. gasar in the juvenile and adult phases. The tested densities affected the survival of oysters cultured over time in both phases but did not affect oyster growth. At times analyzed, it was observed positive growth in juvenile oysters grow after 90 days of culture. However, in the adult phase, no growth was observed after 90 days of culture. Oyster yield was higher in the density 3D, in both juvenile and adult phases. These findings contributed to the development of the oyster C. gasar culture.(AU)

A sobrevivência e o crescimento da ostra nativa Crassostrea gasar nas fases juvenil e adulta foram avaliados sob três diferentes densidades de estocagem [baixa (D), média (2D) e alta (3D)] e dois sistemas de engorda (fixo e flutuante). O sistema fixo consistiu em uma mesa de PVC, fixada na parte inferior com varas de madeira. O sistema flutuante consistiu em travesseiros flutuantes suspensos por uma mesa de PVC e mantidas submersas da superfície da água do mar por oito flutuadores. Registraram-se sobrevivência e altura da concha de ostras cultivadas após 30, 60 e 90 dias, em cada fase (juvenil e adulta) e em cada sistema (fixo e flutuante). Os resultados mostraram que o sistema de engorda não afetou a sobrevivência e o crescimento de C. gasar nas fases juvenil e adulta. As densidades testadas afetaram a sobrevivência das ostras ao longo do tempo, em ambas as fases, mas não afetaram o crescimento em altura. Nos tempos analisados, ostras juvenis apresentaram crescimento após 90 dias de cultivo. Porém, na fase adulta, não foi observado crescimento após 90 dias de cultivo. A produção de ostras, foi maior na densidade 3D, nas fases juvenil e adulta. Os presentes achados contribuíram para o desenvolvimento do cultivo da ostra C. gasar.(AU)

Tecnologic Development on Pleurotus Cultivation: Specific Practices Used in Brazil

HIGHLIGHTS P. ostreatus and P. sapidus are the most productive species under the evaluated conditions. Different growing systems are suitable for the production of P. ostreatus var. Florida. Temperature control level affects differently the P. ostreatus var. Florida isolates. Environmental and strain factors affect yield and production parameters of P. ostreatus var. Florida.

Abstract In Brazil, Pleurotus is the most important mushroom produced especially P. ostreatus var. Florida. In this country as in many others, the great potential for mushroom cultivation remains unexplored. Therefore, it is very important to develop new studies that allow optimizing its production. The aims of the manuscript were: i) to evaluate the productivity of six different species of Pleurotus (P. citrinopileatus; P. djamor; P. ostreatus; P. ostreatus var. Florida; P. pulmonarius; P. sapidus); ii) to measure the effect of three different environmental conditions during cultivation of three isolates of P. ostreatus var. Florida. As results, P. ostreatus and P. sapidus were the most productive isolates under the evaluated conditions. Different environments produced variable effects according to the P. ostreatus var. Florida isolates, being possible to observe a highly plastic strain (POF 02/18), a highly sensitive strain (POF 03/18) and a strain with variable responses (POF 01/18).

Growth Performance of the Mangrove Oyster Cultivated on the Amazon Coast

Abstract In the last decades the oyster faming stands out as the main mitigating measure to the decline of the fishery, as it presents socio-economic and environmental viability. However, for the success of the activity, it is necessary to understand the stages of cultivation, as well as the growth performance of the species to be cultivated. The present work aims to characterize the growth and survival of Crassostrea tulipa, cultivated on the Amazon coast. For this purpose, oysters were grouped by commercial size class (seed, juvenile, baby, average and masters) and compared the growth rates and their relationships with the abiotic variables. There was no difference in the average growth between the oyster classes, however, when comparing them in the total and percentage growth rates, a higher performance was observed in the oysters classified by juvenile and seed, respectively. The relationship of salinity to oyster growth was evidenced only in the class of juvenile oysters. The cultivation time required to obtain native oysters in the commercial size varied between four and seven months, being inferior to those found in other Brazilian regions.

Biological efficiency and nutritional value of Pleurotus ostreatus cultivated in agroindustrial wastes of palm oil fruits and cocoa almonds / Eficiência biológica e valor nutricional de Pleurotus ostreatus cultivados em resíduos agroindustriais de dendê e amêndoa de cacau

The cocoa and palm oil agro-industries active in the state of Bahia, Brazil, generate high quantities of lignocellulosic wastes that could be recycled through their use in the formulation of substrates to cultivate edible mushrooms. Pleurotus ostreatus, also known as oyster mushroom, is the second most cultivated mushroom in the world due to its highly appreciated gastronomic, nutritional, and medicinal characteristics. This work evaluated the vertical mycelium growth, biological efficiency, mushroom yield, and nutritional composition of P. ostreatus produced in substrates formulated with a combination of palm oil fruit mesocarp (POFM) and cocoa almond peels (CAP) processing wastes. The substrates were formulated with the following POFM/CAP proportions (%/%): S1 ­ 86.4/9.6; S2 ­ 76.8/19.2; S3 ­ 67.2/28.8; S4 ­ 57.6/38.4, and S5 ­ 48.0/48.0. Substrates also received 3% powdered charcoal and 1% calcium carbonate. Substrates S1, S2, S3, and S4 were superior for vertical mycelium growth. S2 promoted the best biological efficiency (148.8%) and yield (560.5g·kg-1).The mushrooms produced in all substrates presented good nutritional values, although mushrooms produced using the S2 presented the highest crude protein content. Overall, S1 is the recommended substrate as it results in higher yields of nutrient rich mushrooms. Production of P. ostreatus in substrates composed of POFM and CAP represents a good alternative for recycling these wastes with potential economic and ecological benefits to regions where palm oil and cocoa are grown.(AU)

As indústrias de cacau e óleo de dendê no estado da Bahia, Brasil, geram grandes quantidades de resíduos lignocelulósicos que podem ser reciclados na formulação de substratos para o cultivo de cogumelos comestíveis. Pleurotus ostreatus ou cogumelo ostra é o segundo cogumelo mais cultivado no mundo por apresentar características gastronômicas, nutricionais e medicinais muito apreciadas. Este estudo avaliou o crescimento micelial vertical, a eficiência biológica, a produção e a composição nutricional de P. ostreatus produzido em substratos formulados com a combinação de resíduos do processamento de frutos de dendê (mesocarpo do fruto de dendê ­ MFD) e de amêndoas de cacau (tegumento de amêndoas de cacau ­ TAC). Os substratos foram formulados com as seguintes proporções de MFD e TAC (%/%): S1: 86,4/9,6; S2: 76,8/19,2; S3: 67,2/28,8; S4: 57,6/38,4 e S5: 48,0/48,0. Os substratos também receberam 3% de carvão e 1% de carbonato de cálcio. Os substratos S1, S2, S3 e S4 foram superiores quanto ao crescimento micelial vertical. S2 promoveu os melhores resultados para eficiência biológica (148,8%) e produção (560.5 g·kg-1). Os cogumelos produzidos em todos os substratos apresentaram valores nutricionais promissores. Entretanto, os cogumelos produzidos com o substrato S2 apresentaram o maior conteúdo de proteína bruta. De modo geral, S1 é o substrato recomendado por resultar na maior produção de cogumelos ricos em nutrientes. A produção de P. ostreatus em substratos compostos por MFD e TAC representa uma boa alternativa para a reciclagem desses resíduos com potenciais benefícios econômicos e ecológicos para as regiões produtoras de dendê e cacau.(AU)

Present situation and countermeasure of comprehensive exploitation and utilization of marine traditional Chinese medicine resources / 中草药

Marine traditional Chinese medicine (MCM) is an important part of traditional Chinese medicine (TCM). It has a long history of clinical application and shows its unique advantages. The basic and industrial research represented by MCM seaweed has produced remarkable economic and social benefits, which provides a model for the comprehensive development and utilization of MCM resources. The current situation of exploitation and utilization of MCM resources is systematically discussed, and the strategies and methods of comprehensive exploitation and utilization of MCM resources are put forward. By constructing a full-value industrial chain of MCM resources, applying new technologies and new methods, and combining production, teaching and research with collaborative innovation, the utilization rate of MCM resources can be significantly improved, and the innovation level of marine biomedical industry can be raised. The implementation of the strategy of strengthening the country will promote the development of China's marine economy.

Growth and antioxidant response of juvenile oysters Crassostrea sikamea and Crassostrea corteziensis treated with Streptomyces strains / Crescimento e resposta oxidative de ostras jovens Crassostrea sikamea e Crassostrea corteziensis tratadas com cultura Streptomyces

The effect of three Streptomyces strains (N7, RL8 and V4) and a mixture of Bacillus (BMix) on the growth (Weight, Size) and superoxide dismutase activity (SOD) in hatchery-reared juvenile oysters Crassostrea corteziensis and Crassostrea sikamea was investigated to determine their probiotic potential. Microorganisms were added to culture water at 1×106 CFU/ml once a day during 30 days and all oysters fed daily a microalgae mix. Juveniles of C. sikamea treated with strains N7, RL8 and V4 had a significant weight gain compared to the control group. C. corteziensis juveniles treated with strains RL8 and BMix showed a significantly higher weight gain than the control group. No significant size increase was observed in any treated group for both oyster species. SOD activity significantly increased in C. sikamea treated with RL8 and with RL8, N7 and BMix in C. corteziensis. Streptomyces strains RL8 and N7 emerge as promising probiotic agents to cultivate C. sikamea and C. corteziensis and may also be useful to other molluscs and marine invertebrates .(AU)

O efeito de três culturas Streptomyces (N7, RL8 e V4) e uma mistura de Bacillus (BMix) sobre o cresimento (Peso, Tamanho) e atividade superóxido dismutase (SOD) em ostras jovens Crassostrea corteziensis e Crassostrea sikamea cultivadas artificalmente foi investigado para determinar seu potencial probiótico. Microorganismos foram adicionados à água de cultura a 1×10 6 CFU/ml uma vez por dia durante 30 dias e todas as ostras foram alimentadas diariamente com uma mistura de microalgas. Jovens C. sikamea tratados com culturas N7, RL8 e V4 tiveram ganho de peso significativo quando comparado ao grupo de controle. Jovens C. corteziensis tratados com culturas RL8 e BMix demonstraram peso significativamente mais algo que o grupo de controle. Nenhum aumento em tamanho foi observado em grupos tratados em ambas espécies. A atividade SOD foi significamente aumentada em C. sikamea treatado com RL8 e com RL8, N7 e BMix em C. corteziensis. Culturas Streptomyces RL8 e N7 surgem como agentes probióticos promissores para o cultivo de C. sikamea e C. corteziensis e podem ser úteis para outros moluscos animais marinhos invertebrados.(AU)

Caulerpa lentillifera and Sucrose Formulated Diets as Growth Enhancer of Oyster (Crassostrea virginica)

A total of 200 of Crassostrea virginica populations of average weight range from 41.19 ± 3.42 to 47.53 ± 1.06 g were studied to determine the effect of the feed diets of Caulerpa lentillifera and sucrose as growth enhancement. Growth rates increased that range from 56.99 ± 3.16 to 61.56 ± 2.87 g for 90 days period using an artificial water tank system. Previous studies conducted that C. lentillifera contained high protein and were the most abundant component. This seaweed also contained high amounts of minerals and balanced amino acid and notably very rich in iodine. phosphorus, calcium, magnesium and copper that will contribute to oysters growth. Oysters are known to have the ability to uptake dissolved organic matter as nutrients. In the present study, the effects of culture water supplemented with sucrose were tested on oysters. Results revealed that this organic matter promotes growth to the oysters. Sugars will be metabolized into pyruvate through the glycolysis pathway and will result in the supply of energy. Therefore, supplementation of sugar to oysters may have contributed as an energy source together with the lipid and protein content from the algae diet.

Effects of salinity on the survival and histology of oysters crassostrea gasar (adanson, 1757) / Efeitos da salinidade na sobrevivência e histologia de ostras Crassostrea gasar (Adanson, 1757)

Water salinity is among the most important factors influencing the distribution, abundance, growth, and survival of Crassostrea gasar, an important aquaculture resource grown in estuarine environments in diverse regions of the world. The goal of the present work was to evaluate the effects of different salinities on survival and the tissues ofC. gasar under laboratory conditions. Two experiments were performed using adult oysters from five marine farms located in the bay of Guaratuba, Brazil. In Experiment 1, the daily survival rates were evaluated after the oysters were submitted to gradual acclimatization at salinities ranging from 0 to 65 gL-1 and maintained in the laboratory without feeding for up to 365 days. In Experiment 2, the oysters were exposed to salinity from 0 to 50 gL-1 for up to 30 days without feeding and possible histological alterations caused by salinity were assessed. Three tolerance ranges of C. gasar to salinity were identified: "Optimal" (between 4 and 40 gL-1), "Tolerable" (between 2.1 and 3.9 and between 41 and 50 gL-1) and "Intolerable" (less than 2 and greater than 50 gL-1). No evidence of histological alterations was observed in oysters exposed to the different salinities.

A salinidade da água está entre os fatores de maior influência na distribuição, abundância, crescimento e sobrevivência de Crassostrea gasar, um importante recurso aquícola cultivado em ambientes estuarinos em diversas regiões do mundo. O objetivo desse trabalho foi avaliar os efeitos da salinidade sobre a sobrevivência e nos tecidos de C. gasar exposta a diferentes salinidades, em condições laboratoriais. Foram realizados dois experimentos com ostras adultas provenientes de cinco fazendas marinhas localizadas na baía de Guaratuba, Brasil. No experimento 1, que foi realizado com o propósito de avaliar as taxas diárias de sobrevivência, as ostras foram submetidas à aclimatação gradual a salinidades variando de 0 a 65 gL-1 e mantidas em laboratório, sem alimentação, por até 365 dias. No experimento 2, as ostras foram expostas a salinidades de 0 a 50 gL-1 por até 30 dias, sem alimentação, para avaliação de possíveis alterações histológicas provocadas pela salinidade. Foram identificadas três faixas de tolerância de C. gasar à salinidade: Ótima (entre 4 e 40 gL-1), Tolerável (entre 2,1 e 3,9 e entre 41 e 50 gL-1) e Intolerável (menor que 2 e maior que 50 gL-1). Não foram encontradas evidências de alterações histológicas em função da exposição das ostras às diferentes salinidades.

Ultrastructure of phagocytes and oocysts of Nematopsis sp. (Apicomplexa, Porosporidae) infecting Crassostrea rhizophorae in Northeastern Brazil / Ultraestrutura de fagócitos e oocistos de Nematopsis sp. (Apicomplexa, Porosporidae) infectando Crassostrea rhizophorae no Nordeste brasileiro

Abstract This work describes the detailed ultrastructural morphology of the phagocyte imprisoning an oyster of Nematopsis (Apicomplexa) found in Crassostrea rhizophorae, in the city of Maceió (AL), Brazil. The highly infected hosts had half-open leaflets with weak, slow retraction of the adductor muscles. Variable number of ellipsoid oocytes, either isolated and or clustered, was found between myofibrils of the adductor muscle. Each oocyst was incarcerated in a parasitophorous vacuole of host uninucleated phagocyte. The oocysts were composed of a dense wall containing a uninucleate vermiform sporozoite. The wall of the fine oocysts was composed of homogeneous electron-lucent material formed by three layers of equal thickness, having a circular orifice-micropyle obstructed by the operculum. The oocysts presented ellipsoid morphology with their wall was surrounded by a complex network of numerous microfibrils. Important details of the taxonomic value were visualized such as the ultrastructural organization of the oocyst wall and the organization of the micropyle and operculum, beyond the microfibrils that protrude from the oocyst wall only observed by transmission electron microscopy (TEM) and that may aid in the identification of the species. However, in order to clarify the systematic position of the species reported of the genus Nematopsis, it is important to proceed with genetic analyses.

Resumo Este trabalho descreve a morfologia ultraestrutural detalhada do fagócito encarcerando um oocisto de Nematopsis (Apicomplexa) encontrado em Crassostrea rhizophorae, na cidade de Maceió (AL), Brasil. Os hospedeiros muito infectados apresentavam valvas entreabertas com retração fraca e lenta dos músculos abdutores. Número variável de oócitos de forma elipsoide, isolados e ou agrupados foi encontrado entre as miofibrilas do músculo abdutor. Cada oocisto estava encarcerado num vacúolo parasitóforo do fagócito uninucleado do hospedeiro. Os oocistos eram compostos por uma parede densa contendo um esporozoíto vermiforme uninucleado. A parede dos oocistos finos era composta de material electron-lucente homogêneo formado por três camadas de espessura igual, possuindo um orifício circular - micrópila, obstruída pelo opérculo. Os oocistos apresentavam morfologia elipsoide, sua parede era circundada por uma complexa rede de numerosas microfibrilas. Detalhes de valor taxonômico importantes foram visualizados tais como: a organização ultraestrutural da parede do oocisto e a organização da micrópila e do opérculo, além das microfibrilas que se projetam da parede do oocisto, estrutura apenas observada em microscopia eletrônica de transmissão (MET) e que pode auxiliar na identificação da espécie. Contudo, para esclarecer a posição sistemática da maioria das espécies relatadas do gênero Nematopsis é importante prosseguir com as análises genéticas.

Physical factors affecting oyster diversity and distribution in Southern Thailand

Aim: Studies on oyster population dynamic is essential for effective oyster aquaculture.Bandon Bay in Southern Thailand is a major shellfish aquaculture site of high commercial value. The aim of this study was to evaluate the influence of environmental factors on oyster diversity and their distribution in Bandon Bay. Methodology: Adult oysters were collected from eight aquaculture sites during low tide and their body sizes were measured. Monthly, transparency, salinity, pH, dissolved oxygen, biochemical oxygen demand, alkalinity, ammonium (NH4-N), nitrite, nitrate and phosphate were recorded from Surat Thani Coastal Fisheries Research and Development Centre, Department of Fisheries.Results: Three oyster species were observed: Crassostrea belcheri, Crassostrea lugubris and Saccostrea forskalii, however, C. belcheri was most abundant at most locations. Oyster density in Bandon Bay was mostly influenced by alkalinity, followed by salinity, pH, NO3 and NH4-N.Interpretation: Since oyster reproduction, survival and shell development depend on environmental factors, thus studies on relationships between environmental factors and oyster occurrence/density may provide a better understanding about the community structures and spatial dynamics of oysters, as well as how oysters respond to environmental changes.

Survey of Gymnophalloides seoi Metacercariae in Natural and Cultured Oysters from Several Western Coastal Areas, Korea

Gymnophalloides seoi (Digenea: Gymnophallidae) is a human intestinal trematode contracted by eating raw oysters (Crassostrea gigas) in the Republic of Korea (=Korea). It has been known to be highly endemic in Aphae Island, Shinan-gun, Jeollanam-do (Province). However, recent epidemiological status of G. seoi has not been reported since the 1990s. In this study, we investigated the prevalence of G. seoi metacercariae in natural and cultured oysters collected from 3 islands and 2 coastal areas in western parts of Korea. The oysters were examined using the artificial digestion method followed by stereomicroscopy. The overall positive rate of G. seoi metacercariae in natural oysters was 66.0% (99/150), and the oysters collected from Yubu Island showed the highest infection rate (74.0%). However, the metacercarial density per oyster was relatively low (1.5–2.4 per oyster). By contrast, no metacercaria was found in cultured oysters purchased from 2 coastal areas in Chungcheongnam-do. Thus, we could confirm that natural oysters produced from 3 western coastal islands are infected with G. seoi metacercariae, whereas cultured oysters purchased from 2 coastal areas were free from infection.

Effects of Superfine Grinding Technology on Powder Properties and Dissolution of Oyster Shell / 中国药房

OBJECTIVE： To study the effects of superfine grinding on the powder properties and dissolution of oyster shell， and to provide experimental basis for its comprehensive exploitation. METHODS： Oyster shells were firstly prepared into ordinary powder by grinder. Then the ordinary powder was prepared into micro-powder Ⅰ （crushing 5 min） and Ⅱ （crushing 10 min） by ultrafine pulverizer. The differences of micromeritic properties were investigated before and after superfine grinding from the aspects of particle size distribution， specific surface area and porosity， angle of repose， bulk density， hygroscopicity， etc. Scanning electron microscope （SEM）， Fourier transform infrared spectroscopy （FTIR） and X-ray powder diffraction （XRD） techniques were used to analyze the morphological characteristics and chemical structure of oyster shell before and after superfine grinding. The dissolution were investigated. RESULTS： Compared with ordinary powder， micropowder Ⅰ and micropowder Ⅱ’s were small in particle size and uniformly distributed， but the particles were easy to adhere and aggregate； the specific surface area， porosity and the angle of repose increased， while bulk density decreased； the hygroscopicity increased. FTIR and XRD showed no significant change in chemical structure of oyster shell after superfine grinding. The dissolution rate of micropowder Ⅱ and micropowder Ⅰ was 18.5％ and 10.3％ at 10 min， and the dissolution of ordinary powder was only 6.4％ at 60 min. CONCLUSIONS： Compared with ordinary powder， oyster shell show obvious differences in powder properties after superfine grinding； the dissolution rate of the powders increases， and there is no significant change in chemical structure.

Biomonitoring of Heavy Metals (Fe, Zn, Cu, Mn, Cd and Cr) in Oysters: Crassostrea rhizophorae of Mangrove Areas of Alagoas (Brazil)

Abstract Mangroves are tropical and subtropical flooded forests that generally develop in estuarine areas over unstable sediments protected from the action of waves in the intertidal zone with an environment characterized by a great diversity of fauna and flora. Thus, the present study aimed to evaluate the levels of heavy metals that are absorbed by mangrove oysters, in estuarine systems in the Alagoas coast by determining the concentrations of Fe, Cu, Mn, Zn, Cd and Cr. Two areas, which consisted of both a collection during the rainy season and the dry season, were selected for sampling of mangrove oysters. In each collection, seven samples were collected, at seven different points, where each sample contained four oysters. In the laboratory the oysters were dried at 105°C for 72 hours and then macerated. It was then digested with 10 ml of a solution comprising a combination of 4:1 nitric acid and hydrochloric acid, initially in 1h at 40°C, followed by 3 hours at 140°C. In General, the medians followed the order Zn > Fe > Mn > Cu > Cr > Cd in MMELC and Zn > Cu > Fe > Mn > Cr > Cd in Meirim River. It is concluded that the Crassostrea rhizophorae oysters from the studied environments presented concentrations of all the metals proposed in the research and demonstrates its accumulating and bioindicator character.