Effect of experimental arginine supplementation on the growth,immunity and resistance of tilapia fingerlings to Streptococcus agalactiae     

Rafael Alves Vianna  Roberta Torres Chideroli  Arthur Roberto da Costa  Oswaldo Pinto Ribeiro Filho  Leandro Licursi de Oliveira  Juarez Lopes Donzele  Eduardo Arruda Teixeira Lanna  Daniela Dib Gonalves  Ulisses de Padua Pereira 《Aquaculture Research》2020,51(3):1276-1283

Streptococcosis causes serious economic losses to fish farms every year. A four‐week feeding trial was carried out to evaluate arginine (ARG) supplementation in the diet of Nile tilapia (Oreochromis niloticus) fingerlings challenged by Streptococcus agalactiae. Fish were fed with experimental diets containing five levels of supplementation with 1.39%, 1.76%, 1.97%, 2.18% or 2.39% analysed level of ARG. Each diet was randomly distributed in 30 tanks containing 20 fish/tank. After 30 days, no differences were observed in performance parameters, weight gain, daily weight gain, specific growth rate, feed intake or food conversion. After the performance assay, fingerlings were infected with 1.95 × 10⁸ CFU/fish of Streptococcus agalactiae. Mortality was verified daily, and the respiratory burst of leucocytes and nitric oxide production were measured at 0 hr, 24 hr, 7 days and 15 days after infection. The survival rate of the fish is compared using the Kaplan–Meier method, with values of 4.29%, 14.8%, 10.8%, 17.2% and 33.3% for the 1.39, 1.76, 1.97, 2.18 and 2.39 treatments respectively. A reduction in the mortality rate and a boost in the immune responses was observed in all the supplementations of ARG in the diet; however, the best survival rates were obtained in the treatments with 2.39% ARG as well as the most efficient immune responses.  相似文献   

Growth,mortality and reproductive traits of diploid and triploid Pacific oysters (Crassostrea gigas,THUNBERG, 1793) in Southern Brazil     

Emílio Mateus Costa Melo  Simone Sühnel  Ana Cristina Santos de Oliveira  Brenda de Oliveira Lopes  Gabriela Costa Bachi  Claudio Manoel Rodrigues De Melo 《Aquaculture Research》2020,51(9):3631-3640

This work aimed to evaluate the whole weight (g), shell height (mm), mortality (%) and reproductive aspects (condition index and histology) of triploid (3N) Pacific oysters (Crassostrea gigas) cultivated in southern Brazil. To accomplish this, a comparative experiment was performed with a diploid (2N) control group in two cultivation sites on Santa Catarina Island: North Bay (NB) and South Bay (SB). Whole weight, height and cumulative mortality were evaluated monthly for eight months and condition index (CI) for six months. Histological analysis was performed every two weeks for four months to investigate reproductive aspects. At the end of the experiment, whole weight and height were similar for 3N and 2N oysters. However, while more growth in whole weight and height was observed in the initial phase of cultivation in NB, such growth was not detected in SB until intermediate and final grow‐out phase. At harvest, cumulative mortality in 3N oysters was similar that in 2N oysters. The results suggest that diploid and triploid oysters grown in southern Brazil have similar developmental patterns based on whole weight and height, as well as reproductive cycle. In addition, cultivation sites have more influence on growth and mortality than ploidy levels.  相似文献   

The bone degenerative processes in senile fishes from Holocene Brazilian shell mounds          下载免费PDF全文

O Aguilera  I Rocha  M S Lopes  I Lima  R T Lopes  A S Machado  R B Guimarães  M A C Crapez  M C Tenório  A Nepomuceno 《Journal of fish diseases》2017,40(12):1869-1881

Zooarchaeological collections from shell mounds in Rio de Janeiro (2,470–4,632 cal BP) contain a high prevalence of swollen fish bones belonging to the Atlantic spadefish (Chaetodipterus faber), crevalle jack (Caranx hippos) and fat snook (Centropomus parallelus). Given the lack of knowledge of the bone degenerative process in senile fishes, this study analysed hyperostotic bone in zooarchaeological and modern specimens to obtain high‐resolution morphology and microstructure reconstruction. We used microCT as well as X‐ray diffraction to characterize the crystallographic changes associated with fish senility. Our results showed that trabecular microstructures in hyperostotic bones were consistent with estimated values of the per cent bone volume‐to‐total volume ratio (BV/TV) and were greater than 60% in cortical bone. Hyperostotic bones indicated a high radiograph density, and X‐ray diffractograms showed a decrease in hydroxyapatite [Ca₁₀(PO₄)₆(OH)₂] and calcite (CaCO₃) neocrystallization. These crystalline and density changes revealed an advanced stage of fish senile and indicate the vulnerability of ageing fish populations.  相似文献   

Ultramorphological changes in gill rakers of <Emphasis Type="Italic">Astyanax altiparanae</Emphasis> (Characidae) kept in contaminated environments     

F. P. Lopes  B. F. Pereira  R. M. S. Alves  J. R. T. Valim  F. A. T. Figueiredo  D. L. Pitol  F. H. Caetano 《Fish physiology and biochemistry》2017,43(4):1033-1041

Most water bodies in Brazil, and in the world, are contaminated by some types of pollutants, ranging from sewage to metal/chemicals, carcinogenic products, and biodegradable detergents. Despite the extensive knowledge on their effects on fish biology and especially on gill morphology, research that concerns their impacts on gill rakers and implications in parameters such as food consumption cannot be found in the literature. Gill rakers are vital because, together with gills, they are responsible for the defense and protection of the organism and for selecting appropriate food for survival. When detergents, which can act as toxic chemical agents, get in contact with the body of the fish, they can cause severe effects that must be understood. Therefore, our study investigated ultramorphological changes in gill rakers of Astyanax altiparanae (Lambeth) caused by the exposure to biodegradable detergents. Fish were exposed to a 1 mg/L dilution of a mixture of detergents and pure water from an artesian well for 5 months. Results revealed that the first month of exposure to detergent caused dilation of chemical receptors in taste buds and the rise of a large number of orifices for mucus release among pavement cells in gill rakers, although only a small amount of mucus was found in fish exposed both to pure water and the detergent dilution. After 5 months, there was an increase in the dilation of these chemoreceptors, excess mucus on gill rakers of detergent groups, and the emergence of microbridges between microridges in pavement cells.  相似文献   

Seaweed Blends as a Valuable Source of Polyunsaturated and Healthy Fats for Nutritional and Food Applications     

Francisca Marques  Diana Lopes  Elisabete da Costa  Tiago Conde  Andreia Rego  Ana Isabel Ribeiro  Maria Helena Abreu  Maria Rosrio Domingues 《Marine drugs》2021,19(12)

Seaweeds are considered healthy and sustainable food. Although their consumption is modest in Western countries, the demand for seaweed in food markets is increasing in Europe. Each seaweed species has unique nutritional and functional features. The preparation of blends, obtained by mixing several seaweeds species, allows the obtaining of maximum benefits and ingredients with single characteristics. In this work, five seaweed blends, commercially available and produced under organic conditions in Europe, were characterized. The proximal composition included contents of ash (20.28–28.68% DW), proteins (17.79–26.61% DW), lipids (0.55–1.50% DW), and total carbohydrates (39.47–47.37% DW). Fatty acid profiles were determined by gas chromatography–mass spectrometry (GC–MS), allowing quantification of healthy fatty acids, namely n-3 and n-6 polyunsaturated fatty acids (PUFA), and calculation of lipid quality indices. Each blend showed a characteristic PUFA content in the lipid pool (35.77–49.43% of total fatty acids) and the content in essential and healthy n-3 PUFA is highlighted. The atherogenicity (0.54–0.72) and thrombogenicity (0.23–0.45) indices evidenced a good nutritional value of lipid fractions. As nutritional and environmentally attractive products, the consumption of the studied seaweed blends can contribute to a healthy lifestyle.  相似文献   

Oued Bouhlou: A new hope for the Moroccan pearl mussel          下载免费PDF全文

Ronaldo Sousa  Amílcar Teixeira  André Santos  Hassan Benaissa  Simone Varandas  Mohamed Ghamizi  Vincent Prié  Elsa Froufe  Manuel Lopes‐Lima 《水产资源保护:海洋与淡水生态系统》2018,28(1):247-251

Gibberellic and kaurenoic hybrid strigolactone mimics for seed germination of parasitic weeds          下载免费PDF全文

Rondinelle G Pereira  Antonio Cala  Mónica Fernández‐Aparicio  José MG Molinillo  Maria AD Boaventura  Francisco A Macías 《Pest management science》2017,73(12):2529-2537

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Effect of Steeping Conditions (Sulfur Dioxide,Lactic Acid,and Temperature) on Starch Yield,Starch Quality,and Germ Quality from the Intermittent Milling and Dynamic Steeping Process (IMDS) for a Brazilian Corn Hybrid     

M. S. J. Manzoni  S. N. Kronka  J. F. Lopes‐Filho 《Cereal Chemistry》2002,79(1):120-124

Effect of lactic acid, SO₂, temperature, and their interactions were assessed on the dynamic steeping of a Brazilian dent corn (hybrid XL 606) to determine the ideal relationship among these variables to improve the wet‐milling process for starch and corn by‐products production. A 2×2×3 factorial experimental design was used with SO₂ levels of 0.05 and 0.1% (w/v), lactic acid levels of 0 and 0.5% (v/v), and temperatures of 52, 60, and 68°C. Starch yield was used as deciding factor to choose the best treatment. Lactic acid added in the steep solution improved the starch yield by an average of 5.6 percentage points. SO₂ was more available to break down the structural protein network at 0.1% than at the 0.05% level. Starch‐gluten separation was difficult at 68°C. The lactic acid and SO₂ concentrations and steeping temperatures for better starch recovery were 0.5, 0.1, and 52°C, respectively. The Intermittent Milling and Dynamic Steeping (IMDS) process produced, on average, 1.4% more starch than the conventional 36‐ hr steeping process. Protein in starch, oil content in germ, and germ damage were used as quality factors. Total steep time can be reduced from 36 hr for conventional wet‐milling to 8 hr for the IMDS process.  相似文献