Unsuitability of indigenous South American Rutaceae as potential hosts of Diaphorina citri     

Patrícia A de C Felisberto  Eduardo A Girardi  Leandro Pea  Guilherme Felisberto  George AC Beattie  Silvio A Lopes 《Pest management science》2019,75(7):1911-1920

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Tributaries as biodiversity preserves: An ichthyoplankton perspective from the severely impounded Upper Paraná River     

Patricia Sarai da Silva  Leandro Esteban Miranda  Sergio Makrakis  Lucileine de Assumpo  Joo Henrique Pinheiro Dias  Maristela Cavicchioli Makrakis 《水产资源保护:海洋与淡水生态系统》2019,29(2):258-269

Dietary lipid level and source affect metabolic responses in hybrid catfish (Pseudoplatystoma reticulatum × Leiarius marmoratus)     

Renan Rosa Paulino  Rodrigo Fortes‐Silva  Martha Janeth Prieto‐Guevara  Edgar Junio Damasceno Rodrigues  Leandro Santos Costa  Anglica Priscila do Carmo Alves  Aires Oliva Teles  Priscila Vieira Rosa 《Aquaculture Research》2020,51(4):1567-1583

This study was undertaken to evaluate the effect of dietary lipid source [linseed oil (LO, rich in 18:3 n?3); corn oil (CO, rich in 18:2 n?6); olive oil (OO, rich in 18:1n?9); and fish oil (FO, rich in LC‐PUFA)] and level (9% L and 18% L) on growth, body composition and selected plasma biochemistry parameters in hybrid catfish (Pseudoplatystoma reticulatum × Leiarius marmoratus) juveniles. Moreover, liver histology (lipids, glycogen, cell vacuolization) and key metabolic enzyme activities were also evaluated. After 8 weeks of feeding, there were no differences in growth performance and whole‐body composition between groups. Plasma lipoprotein, muscle and liver composition, and G6PD and ME activity were affected by lipid level and source. No differences were observed between groups in hepatic ALT activity; however, AST activity was lower in fish fed the 9% L diets. Overall, liver and muscle fatty acid composition reflected that of diet FA composition, with increased n3/n6 ratio, high HUFA and low MUFA in fish fed FO compared with the VO diets. Higher liver glycogen content was observed in fish fed the 18% L than the 9% L diets, except for fish fed FO diet. Considering the experimental diets used, these results indicate that hybrid catfish can efficiently utilize VO supplementation as an energy source, without affecting growth performance and fillet composition.  相似文献   

Effects of dietary protein levels on activities of protease and expression of ingestion and protein digestion‐related genes in Nile tilapia juveniles     

Welliene M. Santos  Leandro S. Costa  Jose F. Lpez‐Olmeda  Natlia Cristina S. Costa  Fabio A. C. Santos  Pedro G. Gamarano  Walisson S. Silva  Priscila V. Rosa  Ronald K. Luz  Paula A. P. Ribeiro 《Aquaculture Research》2020,51(7):2973-2984

While some studies have investigated the effects of dietary protein on the activities of protease in Nile tilapia, little information exists about these enzymes and hormones regulating appetite at the molecular level. Therefore, we investigated the performance, protease activities and expression of genes related to protein intake and digestion in juvenile tilapia fed with diets containing different levels of crude protein (CP): 25.14, 31.12, 36.60 and 42.05%. The fish were fed to apparent satiation three times a day for 65 days. The animal performance and the retention rates of protein and energy linearly decreased with an increase in dietary CP content. A positive quadratic effect of CP on pepsinogen was observed, although the acid protease activity was not affected. Trypsinogen and trypsin activity in the intestine presented similar patterns, showing a positive quadratic response to dietary protein levels. A linear increase in intestinal chymotrypsinogen expression was observed, but the activity of chymotrypsin showed a positive quadratic response. In addition, the expression of cholecystokinin (cck) and peptide yy (pyy) increased linearly with increasing CP. Dietary protein modulates the activity of alkaline proteases as well as the expression of these protease genes and hormones involved in appetite regulation. These changes can help expand our understanding of feed intake and digestion control, thereby improving feed formulations for this species.  相似文献   

A fructose‐based extender protects Colossoma macropomum spermatozoa against chilling injuries     

Yugo Moraes Pastrana  Danilo Pedro Streit  Raycon Roberto Freitas Garcia  Bruno Silveira Becker  Jos Luiz Rodrigues  Leandro Godoy 《Aquaculture Research》2019,50(2):521-528

Our study assessed the efficiency of a formulated new extender in maintaining viability and morphological integrity of Colossoma macropomum spermatozoa under chilling storage. Semen was diluted in the test extender and BTS? (Beltsville Thawing Solution) and exposed to a short‐term storage at 4.6 ± 0.6°C for 96 hr. Both extenders were able to maintain 17% ± 8% motile spermatozoa by the end of experiment. Sperm dilution in test extender did not affect the morphologically normal cells (61% ± 6%) up to 48 hr of chilling, being higher than in BTS? (50% ± 6%) (p < 0.05). After 96 hr, samples kept in the test extender had 50% of normal spermatozoa, whereas those kept in BTS? presented only 38% of normal cells. Chilling storage increased the incidence of cells with strongly coiled flagella in BTS^?. Our study is the first to evaluate in detail the spermatozoa morphology as indicative of C. macropomum semen viability. The new extender was able to protect the spermatozoa against increase in coiled flagellum injuries.  相似文献   

Daily rhythms of cortisol and glucose and the influence of the light/dark cycle on anaesthesia in Nile tilapia (Oreochromis niloticus): Does the timing of anaesthetic administration affect the stress response?     

Leandro Santos Costa  Felipe Guedes de Araújo  Renan Rosa Paulino  Luciano Jos Pereira  Edgar Junio Damasceno Rodrigues  Paula Adriane Perez Ribeiro  Priscila Vieira Rosa 《Aquaculture Research》2019,50(9):2371-2379

Although daily variations in drug pharmacokinetics have been reported for a variety of teleost species, the influence of this daily variation on the cortisol response following anaesthesia remains poorly understood. To address this, two experiments were performed. The first experiment described the daily patterns of cortisol and glucose secretion in tilapia (Oreochromis niloticus). The second experiment investigated how the timing of anaesthetic administration (specifically at mid‐light [ML] or at mid‐dark [MD]) affects the induction and recovery times and plasma cortisol and glucose levels of juvenile Nile tilapia exposed to benzocaine, clove oil or tricaine methanesulphonate (MS‐222). The results revealed that the effect on the stress response associated with the moment when anaesthesia took place (ML or MD) varied according to the treatment (p < 0.05). Cortisol levels were significantly higher at ML for MS‐222 (ML = 116.23 ± 25.55; MD = 48.25 ± 22.33 ng/dl) (p < 0.05) and clove oil (ML 59.73 ± 14.27; MD 38.26 ± 12.07 ng/dl) (p < 0.05), whereas no significant differences were found between ML and MD cortisol levels for the control treatment (ML = 72.91 ± 18.42; MD = 64.80 ± 10.68 ng/dl) (p > 0.05) or in the benzocaine‐treated group (ML = 38.7 ± 4.90; MD = 38.60 ± 3.69 ng/dl) (p > 0.05). The highest plasma cortisol level in ML was found in the MS‐222‐treated group. All the tested anaesthetics had similar cortisol levels at MD (p > 0.05).  相似文献   

Trophic Ecology of Arapaima sp. in a ria lake—river–floodplain transition zone of the Amazon          下载免费PDF全文

Felipe Carvalho  Michael Power  Bruce R. Forsberg  Leandro Castello  Eduardo G. Martins  Carlos E. C. Freitas 《Ecology of Freshwater Fish》2018,27(1):237-246

Neotropical floodplains are usually productive systems that are maintained by the nutrient, detritus and sediment inputs provided by the main river channel flood pulse. Ria lakes represent a special feature and habitat in the Amazonian floodplains, being characterised by a dendritic morphology and dependence on terrestrial inputs provided by an intricate stream network. Our objective was to evaluate the trophic ecology of the arapaima (Arapaima sp.). We combined stomach content analysis with measurements of carbon and nitrogen stable isotope values from dorsal muscle to infer the ontogenetic changes in trophic level and isotopic niche width in floodplain and ria lakes. Arapaima diet was dominated by fish from low trophic positions. While most of the stomachs sampled in the study ria lake were full, empty stomachs predominated in samples taken in the floodplain lakes. These differences indicate that ria lakes may provide better feeding grounds for arapaima during the dry season, presumably because ria lakes are interconnected with a large stream network and the main river channel year round. Nitrogen stable isotope results further indicated an ontogenetic dietary shift in arapaima, with piscivory increasing as a function of length in both environments. Carbon stable isotope analysis indicated that energy sources used by arapaima varied by environment, with arapaima using a greater diversity of food sources in ria lakes than in floodplain lakes. Information about the main carbon sources is useful for fishery management because stakeholders may choose to conserve key vegetal groups to ensure the productivity and diversity of aquatic ecosystems.  相似文献   

Immobilization of free-ranging maned wolf (Chrysocyon brachyurus) with tiletamine and zolazepam in central Brazil.     

Mariana Malzoni Furtado  Cynthia Kayo Kashivakura  Claudia Ferro  Jácomo Anah Tereza de Almeida  Leandro Silveira  Samuel Astete 《Journal of zoo and wildlife medicine》2006,37(1):68-70

A tiletamine hydrochloride-zolazepam hydrochloride combination was used successfully to immobilize 27 free-ranging maned wolves (Chrysocyon brachyurus) at a mean dose of 2.77+/-0.56 (mean+/-SD) mg/kg. The induction time ranged from 3-15 min. Animals remained immobilized for periods of 48.56 +/-12.65 min. Compulsive licking, excessive salivation, muscle twitching, muscle tremors, tachypnea, and bradycardia were observed associated with the induction of the anesthesia in 13 of 27 maned wolves. Muscle twitching, pedal withdrawal reflex, muscle tremors, and ataxia were observed during recovery in three (11%) maned wolves. There were no significant differences in heart rates (P = 0.44), respiratory rates (P = 0.82), and rectal temperatures (P = 0.54) recorded at 5, 15, and 25 min after induction at these dosages. The tiletamine hydrochloride-zolazepam hydrochloride combination was shown to be an effective and safe immobilizing agent for free-ranging maned wolves.  相似文献   

Spatial and temporal variability of physical properties of Aquands under different land uses in southern Chile          下载免费PDF全文

José Dörner  Dorota Dec  Oscar Thiers  Leandro Paulino  Felipe Zúñiga  Susana Valle  Oscar Martínez  Rainer Horn 《Soil Use and Management》2016,32(3):411-421

The aquands found in southern Chile are derived from volcanic ash and contain high levels of organic matter. Due to the presence of an impermeable stratum, they have shallow soil profiles, which induce waterlogging for several months each year. These fragile soils, locally known as ‘Ñadi’, cover an area of 475 000 hectares and have undergone intensive land use changes, which have affected the soil physical properties. These are still not well understood but are relevant for the design of efficient drainage systems. The aim of this research was to analyse the impact of the land use change in Ñadi soils on the spatial and temporal variability of their soil physical properties. For the land use change from secondary native forest (sNF) to naturalized grassland (NG), the effective soil depth was measured at defined points. Time‐ and space‐dependent changes of water‐table depth and penetration resistance were recorded. Volumetric water content and soil temperature were measured with sensors installed at three depths and the water retention curve and air permeability at these depths were also determined. The changes in land use over time have induced a reduction in soil depth. Soils under NG showed a smaller soil water storage capacity, air capacity and permeability compared with soils under sNF, as well as waterlogging during winter and greater mechanical strength and soil profile temperatures during summer. Therefore, the land use change affected the spatial and temporal variability of soil physical functions across the field.  相似文献   

Distribution of the equilibrium moisture content in four hardwoods below fiber saturation point with magnetic resonance microimaging     

Passarini  Leandro  Malveau  Cédric  Hernández  Roger E. 《Wood Science and Technology》2015,49(6):1251-1268

Wood Science and Technology - The distribution of liquid and bound water in wood samples under equilibrium moisture contents (EMC) below fiber saturation point (FSP) was assessed by magnetic...  相似文献