Evidence of clandestine harvest and failure of conservation policies for Argopecten purpuratus in the Rinconada Marine Reserve (Chile)          下载免费PDF全文

Miguel Avendaño  Marcela Cantillánez  Gérard Thouzeau 《水产资源保护:海洋与淡水生态系统》2017,27(3):588-603

Environmental impact of razor clam harvesting using salt in Ria Formosa lagoon (Southern Portugal) and subsequent recovery of associated benthic communities     

Rita Constantino  Miguel B. Gaspar  Fábio Pereira  Susana Carvalho  João Cúrdia  Domitília Matias  Carlos C. Monteiro 《水产资源保护:海洋与淡水生态系统》2009,19(5):542-553

• 1. Razor clams are found in different habitats ranging from sheltered systems (e.g. lagoons and estuaries) to open coasts. They are distributed worldwide and comprise a small number of species of high economic value. Depending on the specific habitat and species exploited, different mechanical and hand‐harvesting techniques are employed. While the environmental effects resulting from mechanized methods have been described by several authors, the impacts caused by traditional hand‐harvesting methods remain unknown. Therefore, a study was undertaken in Ria Formosa lagoon (South of Portugal) addressing the environmental effects resulting from harvesting Solen marginatus with salt.
• 2. No significant impact on the sediment was found; the main effect was an increase in salinity after covering the area with salt, which decreased rapidly with the flood tide and after a few hours had returned to pre‐harvesting levels.
• 3. No effects on benthic communities were observed, with similar fluctuation patterns recorded in control and experimental areas, the observed differences being attributed to the natural variability of benthic populations.
• 4. Based on the results obtained in the present study, a razor clam fishery using salt in intertidal areas can be considered environmentally ‘friendly’.

Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Hybridization and invasive species in a threatened freshwater fish community under environmental pressures: Morphometric and molecular evidence     

Lucía Galvez-Bravo  Anabel Perdices  R. J. De Miguel  Ángela Lambea-Camblor  Charlotte Penney  Carlo Meloro  Begoña Martinez-Cruz  Richard P. Brown 《水产资源保护:海洋与淡水生态系统》2024,34(1):e4046

Protein lipid ratio for the growth and survival of juvenile crayfish Procambarus acanthophorus (Hobbs 1972) reared under controlled conditions     

Enrique Cervantes‐Santiago  Martha P. Hernández‐Vergara  Carlos I. Pérez‐Rostro  Miguel A. Olvera‐Novoa 《Aquaculture Research》2010,41(9):e62-e71

The influence of dietary protein/lipid levels on growth and survival in juvenile crayfish (Procambarus acanthophorus) was evaluated during a 12‐week nutritional trial. Twenty experimental diets were formulated containing different protein (200, 250, 300, 350 and 400 g kg^?1) and lipid (60, 80, 100 and 120 g kg^?1) levels. A bifactorial model (5 × 4) was used with three replicates and 15 crayfish (0.014±0.006 g) per replicate, in a recirculation system with 60–15 L rectangular tanks and a biological filter, the culture conditions were a photoperiod of 12:12 h L:D and temperature 24.7±1.0 °C. Total survival ranged from 66.6% to 86.6%, with no differences attributed to treatments. Dietary protein levels had a significant effect on growth gain and nutritional efficiency; in contrast, lipid levels had no effect on juvenile performance. The 250/120 (protein/lipid) treatment promoted the most efficient growth (final weight: 3.09 g, weight gain: 21 995%, specific growth rate: 3.35% day^?1); the less efficient growth was observed in juveniles fed with 400 g kg^?1 protein diets. The quadratic regression model indicated 279 g kg^?1 as the optimal protein level for crayfish growth, while levels between 211 and 232 g kg^?1 could minimize the feeding costs without affecting growth.  相似文献   

Potential bioavailability of protein and lipids in feed ingredients for the three‐spot cichlid Amphilophus trimaculatus: An in vitro assessment     

Francisco J. Toledo‐Solís  Rafael Martínez‐García  Manuel Díaz  Emyr Saul Pea Marín  Maria Paula Di Yorio  Paula Gabriela Vissio  Carlos Alfonso lvarez‐Gonzlez  Miguel Saenz de Rodrigez 《Aquaculture Research》2020,51(7):2913-2925

For the commercial culture of the three‐spot cichlid (Amphilophus trimaculatus), it is important to have available a set of protein and lipid ingredients suitable for feed manufacturing, which allow to optimize the culture at affordable costs. The in vitro digestibility was evaluated with pH‐stat technique, using stomach and intestine multi‐enzymatic extracts from A. trimaculatus juveniles. The digestion of protein ingredients was taken place both in acid and in alkaline conditions, quantifying the total of free amino acids at the end of the hydrolysis, whereas the digestion of lipid ingredients was taken place only in alkaline conditions. The digestive enzymes of this species showed a better affinity to raw materials of animal origin such as beef meal, fish meal and premium chicken meal, which presented better digestibility. The best lipid ingredient that could be used is the fish oil. However, it is possible to use ingredients from the plant sources, such as soy or cereals, and vegetable oils such as olive, corn or soy oil. It is necessary to complement this study in vitro with the digestibility analysis in vivo, in order to determine the inclusion percentages in feeds and costs and therefore to develop an efficient feed formulation for the aquaculture of A. trimaculatus.  相似文献   

Biocontrol of saprolegniosis in rainbow trout (Oncorhynchus mykiss Walbaum) using two bacterial isolates (LE89 and LE141) of Pseudomonas fluorescens     

Concepcin Gonzlez‐Palacios  Juan‐Miguel Fregeneda‐Grandes  Jos‐Miguel Aller‐Gancedo 《Journal of fish diseases》2019,42(2):269-275

The probiotic activity of 15 bacterial isolates that inhibit Saprolegnia parasitica in vitro was tested for the biocontrol of saprolegniosis in rainbow trout (Oncorhynchus mykiss Walbaum), adding the bacteria to tank water for 14 days at a concentration of 10⁶ bacteria ml^?1 water. Pseudomonas fluorescens LE89 and Pseudomonas fluorescens LE141 were effective in controlling experimental infection with S. parasitica since of the fish treated with LE89, 24.5% ± 16.27% (p < 0.05) became infected, as did 42.8% ± 8.41% (p < 0.05) of those treated with LE141. Given their protective effect when administered in water, their effect was also studied when administered in feed before and after experimental infection. Both bacterial isolates survived low pH levels and the action of bile, grew in skin and intestinal mucus, were resistant to several antibiotics and survived in feed; however, neither of the two isolates prevented S. parasitica infection when administered in feed.  相似文献   

Effects of anthropogenic noise as a source of acoustic stress in wild populations of Hippocampus guttulatus in the Ria Formosa,south Portugal     

Jorge Palma  Marisa Magalhes  Miguel Correia  Jos Pedro Andrade 《水产资源保护:海洋与淡水生态系统》2019,29(5):751-759

Impact of Caligus treatments on unit costs of heterogeneous salmon farms in Chile     

Jorge Dresdner  Carlos Chávez  Miguel Quiroga  Daniel Jiménez  Paulina Artacho  Alfredo Tello 《Aquaculture Economics & Management (Blackwell Science)》2019,23(1):1-27

We measure the impact that sanitary treatments that control ectoparasite Caligus rogercresseyi abundance have on unit production costs of Salmo salar farms in Chile. We follow complete production cycles for a sample of farms between 2009 and 2015. We estimate a simultaneous salmon biomass growth and Caligus abundance model. The statistical analysis determines the effect of antiparasitic treatments, location of farms, environmental conditions and Caligus abundance on the salmon growth profile. Using outside cost information, we simulate how unit production costs vary by treatment and farm characteristics. Our results suggest that unit production costs increase on average by $1.4?US/kg with Caligus and treatments. Treatment costs are compensated by higher harvesting levels, and unit production costs are invariant to the situation without treatment. All estimated effects differ depending on farm’s environmental and spatial conditions, suggesting that the design of cost-effective intervention calls for discriminatory regulation under heterogeneous conditions.  相似文献   

Identification of genetic sources with attenuated <Emphasis Type="Italic">Tomato chlorosis virus</Emphasis>-induced symptoms in <Emphasis Type="Italic">Solanum</Emphasis> (section <Emphasis Type="Italic">Lycopersicon</Emphasis>) germplasm     

Matías González-Arcos  Maria Esther de Noronha Fonseca  Ana Arruabarrena  Mirtes F. Lima  Miguel Michereff-Filho  Enrique Moriones  Rafael Fernández-Muñoz  Leonardo S. Boiteux 《Euphytica》2018,214(10):178

The whitefly-transmitted Tomato chlorosis virus (ToCV) (genus Crinivirus) is associated with yield and quality losses in field and greenhouse-grown tomatoes (Solanum lycopersicum) in South America. Therefore, the search for sources of ToCV resistance/tolerance is a major breeding priority for this region. A germplasm of 33 Solanum (Lycopersicon) accessions (comprising cultivated and wild species) was evaluated for ToCV reaction in multi-year assays conducted under natural and experimental whitefly vector exposure in Uruguay and Brazil. Reaction to ToCV was assessed employing a symptom severity scale and systemic virus infection was evaluated via RT-PCR and/or molecular hybridization assays. A subgroup of accessions was also evaluated for whitefly reaction in two free-choice bioassays carried out in Uruguay (with Trialeurodes vaporariorum) and Brazil (with Bemisia tabaci Middle-East-Asia-Minor1—MEAM1?=?biotype B). The most stable sources of ToCV tolerance were identified in Solanum habrochaites PI 127827 (mild symptoms and low viral titers) and S. lycopersicum ‘LT05’ (mild symptoms but with high viral titers). These two accessions were efficiently colonized by both whitefly species, thus excluding the potential involvement of vector-resistance mechanisms. Other promising breeding sources were Solanum peruvianum (sensu lato) ‘CGO 6711’ (mild symptoms and low virus titers), Solanum chilense LA1967 (mild symptoms, but with high levels of B. tabaci MEAM1 oviposition) and Solanum pennellii LA0716 (intermediate symptoms and low level of B. tabaci MEAM1 oviposition). Additional studies are necessary to elucidate the genetic basis of the tolerance/resistance identified in this set of Solanum (Lycopersicon) accessions.  相似文献   

Effect of the Cooking Process on the Gelling Properties of Whole and Minced Jumbo Lump of Blue Crab (Callinectes sapidus)     

Miguel Angel Martínez-Maldonado  José Alberto Ramírez-De León  Ma. Guadalupe Méndez-Montealvo  Eduardo Morales-Sánchez 《Journal Of Aquatic Food Product Technology》2018,27(4):418-429

Commercially, crab meat is obtained by hand-picking after a cooking process, followed by pasteurizing or canning. Jumbo lump is one of the pieces of meat obtained from the blue crab. The aim of this study was to evaluate the effect of the commercial cooking process (boiling and steaming) on the mechanical and functional properties of whole jumbo lump and the gels obtained from cooked and minced jumbo lump from blue crab (Callinectes sapidus). The gels were prepared combining the washing process and microbial transglutaminase. The boiling and steaming processes showed a different effect on the textural and color properties. Whole jumbo lump pieces cooked by immersion in boiling water showed a higher hardness value as compared to steamed jumbo lump pieces, suggesting a different internal structural. The cooking processes used in this study did not modify the water holding capacity, gelling capability, or color of the minced jumbo lump. The addition of microbial transglutaminase to washed minced jumbo lump improved the hardness, cohesiveness, and chewiness of gels elaborated with boiled or steamed jumbo lump, which allowed the textural properties similar to those of the whole jumbo lump.  相似文献