Digestive Enzyme Activity during Larval Development of Black Snook,Centropomus nigrescens          下载免费PDF全文

Carlos Yanes‐Roca  Mayra E. Toledo‐Cuevas  Lizbeth J. Sánchez  Ana Born‐Torrijos  Nicole Rhody  Kevan L. Main 《Journal of the World Aquaculture Society》2018,49(3):612-624

Black snook, Centropomus nigrescens, have been identified as a promising candidate for aquaculture although, like many of the Centropomid species, high mortality associated with early larval stages presents a significant bottleneck to their commercialization. The digestive capacity of black snook larvae throughout the first 37 d after hatch (d.a.h.) was evaluated by quantifying digestive enzyme activities using biochemical techniques. Results showed that black snook larvae have alkaline proteases at hatching, which are known to be important during the first days of feeding for digestion. Toward the end of the study, acid proteases concentration increased (37 d.a.h.). Enzymes for lipid digestion, pancreatic lipase and bile salt‐activated lipase, were already present in the larvae before exogenous feeding commenced, and their activity increased with age and growth (length). Intracellular digestion, measured as the activity of leucine‐alanine peptidase, was high early on (5 d.a.h.) and decreased as development progressed (next 32 d). In contrast, alkaline phosphatase activity was lowest at first feeding and subsequently increased with age. Overall patterns in enzyme activity suggest the possibility of live feed weaning before 32 d.a.h. if artificial diets can be properly balanced.  相似文献   

Comparative Characterization of Enzymatic Digestion from Fish and Soybean Meal from Simulated Digestive Process of Pacific Bluefin Tuna,Thunnus orientalis          下载免费PDF全文

Ariana I. Román‐Gavilanes  Emmanuel Martínez‐Montaño  María Teresa Viana 《Journal of the World Aquaculture Society》2015,46(4):409-420

The digestive process of the Pacific bluefin tuna (PBT), Thunnus orientalis, was simulated through two phases of in vitro digestion: acidic digestion with porcine pepsin, followed by alkaline digestion with pancreatic crude extract (PCE) obtained from the PBT to hydrolyze fish meal (FM) and soybean meal (SBM) as protein substrates. The crude protein from FM resulted in a lower degree of hydrolysis (73.3%) compared with SBM (79.2%). However, the resulting digested products showed that FM contained 35% more small peptides, with sizes <6.5 kDa than those from the starting material (>150 kDa). The SBM had an increase of only 1.3% in the similar peptide cut‐offs found after hydrolysis. These results suggested that FM appeared to be a better source of protein according to the amount of low‐molecular weight peptides. In addition, the proteolytic activity of PCE showed that 88.9% of its alkaline proteolytic activity corresponded to trypsin and 2.9% corresponded to chymotrypsin activity. The results shown here demonstrate that peptide sizes are important in identifying suitable protein sources for aquafeed production to reinforce the primary results obtained from the in vitro digestibility using the pH‐Stat system. These results also contribute to a better understanding of the digestibility process in aquatic organisms.  相似文献   

Associations of fish with various types of littoral habitats in reservoirs     

Marek Šmejkal  Marie Prchalová  Martin Čech  Mojmír Vašek  Milan Říha  Tomáš Jůza  Petr Blabolil  Jan Kubečka 《Ecology of Freshwater Fish》2014,23(3):405-413

Fish associations with different types of littoral habitats were studied in four canyon‐shaped reservoirs in the Czech Republic in years 2010 and 2011 by gillnets. Two to three habitats per reservoir–beaches (former meadows), stump fields (former forest) and rubble slopes–were defined and sampled along the longitudinal axis of reservoirs. Effects of reservoir, habitat and locality (position along longitudinal axis) on fish biomass, abundance and species structure were tested for juvenile and adult fish separately. Hierarchical analysis of variance revealed that habitats differed significantly in fish biomass and abundance. Redundancy analysis showed that analysed environmental variables had significant influence on fish community structure. Most variability in community structure was explained by reservoir and then by combination of habitat and slope steepness. Locality position had the smallest influence on community structure. For both adult and juvenile fish total abundance and biomass, the most inhabited habitat was beaches; rubble slopes were the least inhabited. Habitat associations differed among species. Among adults, bream Abramis brama, white bream Blicca bjoerkna and roach Rutilus rutilus were associated with beaches and stump fields, whereas perch Perca fluviatilis, ruffe Gymnocephalus cernuus, asp Aspius aspius and pike Esox lucius were associated with rubble slopes. Bream, white bream, bleak Alburnus alburnus, roach, ruffe and pikeperch Sander lucioperca were associated with beaches among juveniles, whereas the only juvenile associated with rubble slopes was perch. We showed that most common species are associated with distinct habitats and also that utilisation of various littoral habitats differs in general.  相似文献   

Successive grafting confers juvenility traits to adult Spanish red cedar (Cedrela odorata Linnaeus): a tool for the rescue of selected materials     

Robert  Manuel L.  Juárez-Gómez  Juan  Chaires-Pacheco  Mariana  Peña-Ramírez  Yuri J. 《New Forests》2020,51(2):335-347

New Forests - Spanish red cedar, Cedrela odorata L. (Meliaceae), is a valuable timber tree in tropical American forests. Existing demand for elite individuals endangers the conservation of...  相似文献   

Characterization,Pathogenicity and Chemical Control of <Emphasis Type="Italic">Streptomyces acidiscabies</Emphasis> Associated to Potato Common Scab     

María Elena Santos-Cervantes  Ruben Felix-Gastelum  Gabriel Herrera-Rodríguez  Mariela Guadalupe Espinoza-Mancillas  Arlene Guadalupe Mora-Romero  Norma Elena Leyva-López 《American Journal of Potato Research》2017,94(1):14-25

The pathogenicity of 10 bacterial isolates was investigated on potato, radish, carrot and beet, including sensitivity and pathogen control efficacy. The isolates were identified by morphological, biochemical and molecular methods. All isolates were pathogenic on radish, carrot, and beet, and were highly virulent on potato. Although the isolates were obtained from different locations in the El Fuerte Valley (Sinaloa, Mexico), they were similar in their morphological, physiological and biochemical characteristics. Sequences of the 16S rRNA gene obtained by PCR were identical for all isolates. These results indicate that the bacterial isolates from potato scabby tissue belong to S. acidiscabies. Furthermore, the effectiveness of fluazinam, both in vitro and under greenhouse and field conditions, represents a possibleoption for chemical control of potato common scab disease. While our results suggest that spraying at seeding is effective in controlling common scab, future studies to combine this treatment with seed dressing before planting will be conducted to determine if there is an increase in disease control.  相似文献   

Digestibility of Quinoa (<Emphasis Type="Italic">Chenopodium quinoa</Emphasis> Willd.) Protein Concentrate and Its Potential to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model     

R. Vilcacundo  D. Barrio  C. Carpio  A. García-Ruiz  J. Rúales  B. Hernández-Ledesma  W. Carrillo 《Plant foods for human nutrition (Dordrecht, Netherlands)》2017,72(3):294-300

Quinoa protein concentrate (QPC) was extracted and digested under in vitro gastrointestinal conditions. The protein content of QPC was in the range between 52.40 and 65.01% depending on the assay used. Quinoa proteins were almost completely hydrolyzed by pepsin at pH of 1.2, 2.0, and 3.2. At high pH, only partial hydrolysis was observed. During the duodenal phase, no intact proteins were visible, indicating their susceptibility to the in vitro simulated digestive conditions. Zebrafish larvae model was used to evaluate the in vivo ability of gastrointestinal digests to inhibit lipid peroxidation. Gastric digestion at pH 1.2 showed the highest lipid peroxidation inhibition percentage (75.15%). The lipid peroxidation activity increased after the duodenal phase. The digest obtained at the end of the digestive process showed an inhibition percentage of 82.10%, comparable to that showed when using BHT as positive control (87.13%).  相似文献   

Survival and Growth Improvement of Palm Ruff,Seriolella violacea,Larvae Fed Artemia Nauplii Enriched with an Experimental Emulsion          下载免费PDF全文

Adens González  Alfonso Silva  Gonzalo Gajardo  Claudio Martínez 《Journal of the World Aquaculture Society》2017,48(2):268-279

The palm ruff, Seriolella violacea (Cojinoba), is a potential new species for Chilean aquaculture. To approach Cojinoba larviculture, an experimental Artemia enrichment emulsion, containing docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) = 2.5, supplemented with vitamin E, astaxanthin, and β‐glucan, was evaluated in both Artemia and Cojinoba larvae, 30–50 d.a.h. This study tested an experimental enrichment emulsion versus a commercial emulsion, with an integral approach of multicompound emulsions. After 23 h enrichment, experimental emulsion (EE)‐enriched nauplii reached DHA and EPA concentrations of 23.8 and 18.7 mg/g dry weight (dwt), respectively, while in Cojinoba larvae they were 18.4 and 19.7 mg/g dwt. Control emulsion (CE)‐enriched nauplii exhibited lower DHA and EPA (6.1 and 7.7 mg/g dwt), while only DHA decreased in the control larvae (12.6 mg/g dwt). Vitamin E was higher in EE‐enriched nauplii (29.2 mg/100 g dwt) than in the control (8.4 mg/100 g dwt). Larvae fed EE‐enriched Artemia exhibited 8% increase in survival and 19% in growth compared with the control. Astaxanthin was detected only in larvae fed EE‐enriched nauplii. The tumor necrosis factor‐α concentration was not significantly different between larvae fed EE‐ and CE‐enriched nauplii. EE looks promising as an Artemia enrichment and experimental diet to assess palm ruff larval requirements, and has a positive impact on fish larvae performance.  相似文献   

Comparison of selection methods among and within full-sibling progenies in Urochloa humidicola     

Yasmin Vasques Berchembrock  Ulisses José de Figueiredo  José Airton Rodrigues Nunes  Cacilda Borges do Valle  Sanzio Carvalho Lima Barrios 《Grass and Forage Science》2020,75(2):145-152

Hybridization in the Urochloa humidicola breeding programme allowed to explore the genetic variability of the apomictic sources and, thus, to obtain new sexual and apomictic parents with compatible ploidy and/or superior progenies. However, given the high variability arising from crosses, there is a need to adopt efficient selection strategies among and within progenies. The aim of this study was to compare the selection methods among U. humidicola progenies with (t-BLUP) and without (BLUP) the weighting based on prediction error and subsequent selection within progenies by individual simulated (BLUP_IS) or optimal individual BLUP. We evaluated seventy-one U. humidicola full-sib progenies from biparental crosses between nine sexual and ten apomictic parents. The experiment was set up in an incomplete block design with 64 blocks of 15 plots each, consisting of individual plants. Seven consecutive cuts were made and the traits total dry-matter, leaf dry-matter and regrowth scores were measured. Genetic variance was expressive for all traits. The selection procedure among progenies of U. humidicula based on t-BLUP proved to be more advantageous regarding the use of BLUP not weighted by the prediction error, resulting in higher selection gains, taking as reference the optimal procedure of the individual BLUP. Furthermore, the use of BLUP_IS allowed an optimized selection of hybrids, allowing the breeder to explore with variable selection intensity the genetic variability within the selected full-sib progenies based on relative genetic merit.  相似文献   

Comparison of Chemical Composition and Biological Properties of Essential Oils Obtained by Hydrodistillation and Steam Distillation of Laurus nobilis L.     

Řebíčková  Kristýna  Bajer  Tomáš  Šilha  David  Ventura  Karel  Bajerová  Petra 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(4):495-504

Plant Foods for Human Nutrition - The purpose of this study was to compare the yield, chemical composition, antimicrobial and antioxidant properties of essential oils isolated from leaves of Laurus...  相似文献   

Biological Activities of Chickpea in Human Health (Cicer arietinum L.). A Review     

Faridy  Juárez-Chairez Milagros  Stephanie  Cid-Gallegos María  Gabriela  Meza-Márquez Ofelia  Cristian  Jiménez-Martínez 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(2):142-153

Plant Foods for Human Nutrition - Chickpea is one of the most consumed legumes worldwide. Among their benefits are the high protein concentration that reflects not only at the nutritional level but...  相似文献