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901.
Raúl Laiz-Carrión Inês Rosa Viana Juana Rosa Cejas Ignacio Ruiz-Jarabo Salvador Jerez Juan Antonio Martos Almansa Berro Eduardo Juan Miguel Mancera 《Aquaculture International》2012,20(3):585-599
In the present study, the influence of high stocking density and food deprivation on red porgy (Pagrus pagrus L.) energy metabolism was investigated after 14 and 21?days assessing plasmatic, hepatic, and muscular parameters. Specimens were submitted to four different experimental conditions: (1) fed fish under low stocking density (4?kg?m?3, LSD-F); (2) food-deprived fish under low stocking density (LSD-FD); (3) fed fish under high stocking density (50?kg?m?3, HSD-F); and (4) food-deprived fish under high stocking density (HSD-FD). At plasmatic level, cortisol concentration enhanced in fish maintained under HSD condition, with higher effect in fed fish, whereas FD condition decreased values of lactate, protein, and triglycerides. In liver, significant increases in triglyceride levels, together with a decrease in glycogen values, were observed in FD specimens. Furthermore, a weak effect of density in fed fish was observed, with decreasing hepatic glycogen. In white muscle, aminoacid and triglyceride values diminished in FD group, while increased in specimens submitted to HSD condition. Our results suggested an enhancement in P. pagrus gluconeogenic and glycogenolytic potential when submitted to HSD and FD conditions to cope reallocation of metabolic energy due to these different stress situations. 相似文献
902.
Ana Rodiles Ester Santigosa Marcelino Herrera Ismael Hachero-Cruzado María Luisa Cordero Silvia Martínez-Llorens Santosh P. Lall Francisco Javier Alarcón 《Aquaculture International》2012,20(6):1053-1070
The effect of dietary protein level and protein source on growth and proteolytic activity of juvenile Solea senegalensis was studied. In Experiment 1, fish were fed on four experimental diets containing increased protein levels (36, 46, 56 and 67%). In Experiment 2, Senegalese soles were fed on five diets with partial substitution of fish meal by soybean meal, soybean protein concentrate, soybean protein isolate, wheat gluten meal or pea protein concentrate. Results prove that growth and proteolytic activity in the distal intestine of fish were affected by the quantitative increase in dietary protein. The origin of protein source used in the elaboration of experimental diets affected both the amount and composition of the alkaline proteases secreted into the intestinal lumen; however, it did not decrease animal growth. Juvenile Senegalese sole showed capability to modulate digestive protease secretion when the concentration and/or source of dietary protein were modified. Quantity and quality of dietary protein affected protein hydrolysis in Senegalese sole intestine. This study establishes that 30% fish meal protein can be replaced by soybean derivatives without affecting intestinal proteases. Replacement with wheat gluten meal or pea protein concentrate should be taken cautiously, but further research is needed to establish whether growth performance and digestive enzyme physiology of Senegalese sole are affected by plant protein-supplemented diets in a long-term trial. 相似文献
903.
Eduardo P. Pérez Andrea Araya Marcelo Araneda Claudio Zú?iga 《Aquaculture International》2012,20(2):333-345
The variability in growth is a common characteristic in mollusks breeding. Effects rising from the variability in the individual
growth rate and the consequent dispersion of sizes in cultivation are important in financial terms. To manage this heterogeneity
many firms use size selection, which can happen in two stages: toward the end of the stage of growing, or in the phase of
growing of seeds. A bioeconomic model simulating the operation of a firm producing red abalone was implemented in spreadsheets.
The firm produces 70 tons yearly. The model was structured in three sub-models. A biological sub-model detailed a batch’s
dynamics, in terms of survival and growth, considering individual variation of size around a central value for each age. A
technological sub-model described raw materials, the quantity of food and the energy required. Finally, the simulation model
is completed with an economic integrated sub-model, where net present value is calculated considering income and costs over
the time. Results of the alternative production strategies (with or without selection) are assessed according to: quantity
of larvae and necessary spawners to reach the desired level of production; net present value (NPV) and necessary time to recover
the investment. The number of larvae was approximately 17 millions larger for the case of the strategy of production with
sizes selection and 73% more of available spawners is required for this larger amount of larvae. In the short term, the size-selection
strategy increases the production costs at the initial time, compared with the strategy without selection. However, in the
long term, this strategy generates greater NPV. The span for investment recovery was shorter for the case of the strategy
with size selection and living product (nearly 2,140 days) than frozen (nearly 2,232 days); while without sizes selection
a 15-year simulation showed the investment is not recovered. Finally, could be verified that size selection can be an interesting
strategy to explore, since it improves the financial result, the same way other more expensive technological changes would. 相似文献
904.
Silvia Martínez‐Llorens Ana Tomás Vidal Miguel Jover Cerdá 《Aquaculture Research》2012,43(11):1697-1709
The economic profitability of fish meal replacement by soybean meal and pea‐rice concentrate mixture, was analysed considering the economic conversion ratio (ECR) and the economic profit index (EPIst) as a proposal for evaluating the economic profitability in diets for sea bream. The optimal fish meal levels for minimizing the ECR were 33% (when soybean meal was included) and 14% (in the case of pea‐rice concentrate mixture) and for maximizing the EPIst, optimal fish meal levels were 31% and 28.8%, respectively, considering the current market price of fish meal and vegetal ingredients. The EPIst, seems to be a better index than the ECR to estimate diet profitability, because it considers weight increment, feed conversion ratio, diet cost and fish sale price. A sensibility analysis was conducted, considering variations in the price of fish meal and vegetal ingredients. Finally, several multiple regressions were developed for estimating the optimal level of fish meal with each vegetable ingredient and the expected value of the economic profit as a function of the market price of both fish meal and plant protein. When fish meal prices increase, the highest beneficial level of the inclusion fish meal and the highest economic profit would be achieved with pea‐rice mixture. 相似文献
905.
Inés Martínez‐Pita Ismael Hachero‐Cruzado Clara Sánchez‐Lazo Oscar Moreno 《Aquaculture Research》2012,43(8):1134-1144
This paper describes the lipid composition of the commercial bivalve Donax trunculus and the differences originated when the animals were fed with two phytoplankton species (Tetraselmis suecica and Chaetoceros sp.) in a hatchery. We also analysed sex‐related differences in lipid classes and fatty acid profile. Total lipids were higher in females than in males. Triglycerides and phospholipids were the major lipid components, and the former dominated in females and the latter in males. The main fatty acids in both sexes were 16:0, 20:5n‐3 (eicosapentaenoic acid) and 22:6n‐3 (docosahexaenoic acid). Females showed higher percentages of saturated and monounsaturated fatty acids and lower levels of polyunsaturated fatty acids than males. Significant differences in total lipid, lipid classes and fatty acid profiles were also found due to diet. Docosahexaenoic acid decreased and total lipids, free fatty acids, arachidonic acid and EPA increased in both sexes. Despite these differences, the condition of the species was maintained and the broodstock even maturated. 相似文献
906.
Melissa A. Fitzgerald Christine J. Bergman Adoracion P. Resurreccion Jürgen Mller Rosario Jimenez Russell F. Reinke Margrit Martin Pedro Blanco Federico Molina Ming‐Hsuan Chen Victoria Kuri Marissa V. Romero Fatemeh Habibi Takayuki Umemoto Supanee Jongdee Eduardo Graterol K. Radhika Reddy Priscila Zaczuk Bassinello Rajeswari Sivakami N. Shobha Rani Sanjukta Das Ya Jane Wang Siti Dewi Indrasari Asfaliza Ramli Rauf Ahmad Sharifa S. Dipti Lihong Xie Nguyen Thi Lang Pratibha Singh Dmaso Castillo Toro Fatemeh Tavasoli Christian Mestres 《Cereal Chemistry》2009,86(5):492-498
Amylose content is a parameter that correlates with the cooking behavior of rice. It is measured at the earliest possible stages of rice improvement programs to enable breeders to build the foundations of appropriate grain quality during cultivar development. Amylose is usually quantified by absorbance of the amylose‐iodine complex. The International Network for Quality Rice (INQR) conducted a survey to determine ways that amylose is measured, reproducibility between laboratories, and sources of variation. Each laboratory measured the amylose content of a set of 17 cultivars of rice. The study shows that five different versions of the iodine binding method are in use. The data show that repeatability was high within laboratories but reproducibility between laboratories was low. The major sources of variability were the way the standard curve was constructed and the iodine binding capacity of the potato amylose used to produce the standard. Reproducibility is much lower between laboratories using a standard curve of potato amylose alone compared with those using calibrated rice cultivars. This study highlights the need to standardize the way amylose is measured, and presents research avenues for doing so. 相似文献
907.
Renata Pardini Deborah Faria Gustavo M. Accacio Eduardo Mariano-Neto Mateus L.B. Paciencia Marianna Dixo 《Biological conservation》2009,142(6):1178-1190
Recent developments have highlighted the importance of forest amount at large spatial scales and of matrix quality for ecological processes in remnants. These developments, in turn, suggest the potential for reducing biodiversity loss through the maintenance of a high percentage of forest combined with sensitive management of anthropogenic areas. We conducted a multi-taxa survey to evaluate the potential for biodiversity maintenance in an Atlantic forest landscape that presented a favorable context from a theoretical perspective (high proportion of mature forest partly surrounded by structurally complex matrices). We sampled ferns, butterflies, frogs, lizards, bats, small mammals and birds in interiors and edges of large and small mature forest remnants and two matrices (second-growth forests and shade cacao plantations), as well as trees in interiors of small and large remnants. By considering richness, abundance and composition of forest specialists and generalists, we investigated the biodiversity value of matrix habitats (comparing them with interiors of large remnants for all groups except tree), and evaluated area (for all groups) and edge effects (for all groups except trees) in mature forest remnants. Our results suggest that in landscapes comprising high amounts of mature forest and low contrasting matrices: (1) shade cacao plantations and second-growth forests harbor an appreciable number of forest specialists; (2) most forest specialist assemblages are not affected by area or edge effects, while most generalist assemblages proliferate at edges of small remnants. Nevertheless, differences in tree assemblages, especially among smaller trees, suggest that observed patterns are unlikely to be stable over time. 相似文献
908.
Wagner de Souza Tavares Ivan Cruz Fernando Petacci Sebastio Loureno de Assis Júnior Silvia de Sousa Freitas Jos Cola Zanuncio Jos Eduardo Serro 《Industrial Crops and Products》2009,30(3):384-388
Extracts of 12 Asteraceae were tested on Spodoptera frugiperda (Lepidoptera: Noctuidae) and on their parasitoids Telenomus remus (Hymenoptera: Scelionidae) and Trichogramma pretiosum (Hymenoptera: Trichogrammatidae). The plants Lychnophora ericoides and Trichogonia villosa were toxic for 97.7 ± 0.15% of one-day-old eggs of S. frugiperda and Lepidaploa lilacina for 72.0 ± 2.50% for two-day-old eggs of this insect. Extracts of Vernonia holosenicea, Lychnophora ramosissima and Chromolaena chaseae had higher impact on S. frugiperda, while those of Eremanthus elaeagnus and L. ericoides were more selective to T. pretiosum and T. remus. Asteraceae extracts present potential for integrated pest management programs of S. frugiperda. 相似文献
909.
Distribution and intensity of bottom trawl fisheries in the Patagonian Shelf Large Marine Ecosystem and its relationship with marine fronts
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Trawling is a major concern worldwide and there is considerable debate about its impact on marine ecosystems. The Patagonian Shelf Large Marine Ecosystem (PSLME) is an important fishing area in the Southwest Atlantic where bottom trawling is the dominant fishing method. We investigated the distribution of bottom trawl fishing within this region, defining the areas of highest trawling intensity (hotspots) and evaluating their relationship with marine fronts. We focused on the three main oceanographic fronts, the shelf‐break front, the southern Patagonia front and the mid‐shelf front. To estimate fishing effort and trawled areas, we used VMS data from 2006 to 2012. Despite being almost a fully trawlable shelf, we found that the spatial distribution of trawling activity is patchy and trawling hotspots were small, comprising annually <5% of the shelf extension or <7% of the total trawlable area. Contrary to what is believed worldwide, our findings suggest that over the PSLME the magnitude of habitat effects as a result of bottom trawling is relatively small. Regarding the three frontal systems studied, only the shelf‐break front showed a positive relationship with trawl fishing activity. Although trawling hotspots did not overlap with marine fronts, the shelf‐break front receives more trawling effort than expected. We hypothesize that this pattern is due to aggregation of species near or at the front taking advantage of the opportunities provided by this area. 相似文献
910.
Partial characterization of digestive proteases of the three‐spot cichlid Cichlasoma trimaculatum (Günter 1867)
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F.J. Toledo‐Solís G. Márquez‐Couturier A. Uscanga‐Martínez R. Guerrero‐Zárate N. Perales‐García R. Martínez‐García W.M. Contreras‐Sánchez S. Camarillo‐Coop C.A. Álvarez‐González 《Aquaculture Nutrition》2016,22(6):1230-1238
Partial characterization of digestive proteases in the three‐spot cichlid Cichlasoma trimaculatum juveniles was conducted. It was determined that there is higher alkaline proteases activity (3.95 ± 0.32 IU mg?1 protein) compared to acidic proteases (2.01 ± 0.57 IU mg?1 protein). Optimal temperature for alkaline proteases is 60 °C which resulted in more thermostability to temperature changes. On the other hand, optimal temperature for acidic proteases is 50 °C. Optimal pH for acidic proteases was pH 2, while for alkaline proteases, it was pH 10, which resulted in more stability in relation to pH changes than acidic protease. The use of specific inhibitors and the SDS‐PAGE electrophoresis analysis revealed seven types of bands for alkaline proteases, which make evident the main presence of serine proteases. In acidic proteases, more than 98 g kg?1 of the activity was inhibited with pepstatin A inhibitor. Therefore, it is evident that C. trimaculatum digestion is composed by acidic and alkaline proteases; thus, it should be considered an omnivorous fish. 相似文献