The role of ecological context and predation risk-stimuli in revealing the true picture about the genetic basis of boldness evolution in fish

To showcase the importance of genotype × environment interactions and the presence of predation risk in the experimental assessment of boldness in fish, we investigated boldness in terms of feeding behavior and refuge use in two genetically different populations of juvenile carp (Cyprinus carpio) in two replicated experimental conditions in ponds and laboratory tanks. The populations were expected to exhibit genetic differences in boldness due to differential evolutionary adaptation to low-predation-risk pond aquaculture conditions. Boldness was measured in variants of open-field trials with and without implementation of additional predation risk-stimuli by angling on feeding spots. Without explicit implementation of risk, genotypes adapted to low-risk environments, i.e., domesticated mirror carp behaved consistently bolder than their less domesticated scaled conspecifics in the pond environment, but not in the laboratory environment. When we implemented artificial risk-stimuli by angling on previously safe feeding spots, boldness differences among genotypes also emerged in the laboratory environment, indicating strong genotype × environment effects on boldness behavior of carp. The expected genetic basis of boldness differences among genotypes was clearly supported in the pond environment, while the laboratory study revealed these patterns only under inclusion of explicit risk-stimuli. Our study thus underscores that boldness may involve both a basal component that is expressed independently of obvious predation risk (e.g., in open fields) and a component revealed in relation to explicit predation risk, and both dimensions may respond differently in behavioral tests.     

Intrasexual competition,territoriality and acoustic communication in male strawberry poison frogs (<Emphasis Type="Italic">Oophaga pumilio</Emphasis>)

In many species male reproductive success is limited by access to females. Territoriality is one behavioural strategy which helps to acquire females. In the present study, we investigated the correlation between territory size and (1) female availability and (2) rate of intrusion by conspecific males in strawberry poison frogs, Oophaga pumilio. Males defended smaller territories in areas with a high female density and high rate of intrusion by conspecific males. Only males with high body condition values were able to establish territories in areas of high female density probably due to better fighting abilities. Moreover, dominant calling frequency was lower during agonistic interactions. Because only males with high body condition values were able to produce very low dominant frequencies, the acoustic properties appear to be an honest signal containing information about fighting abilities. Thus, the negative correlation between dominant frequency and mating success of males found in previous studies seems to be in part the result of intrasexual competition between males.     

Life cycle assessment of upflow anaerobic sludge blanket sludge management and activated sludge systems aiming energy use in the municipality of Itajubá, Minas Gerais,Brazil

Journal of Material Cycles and Waste Management - This study aimed to carry out the Life Cycle Analysis (LCA) targeting to decide the better management system for sludge from both Activated Sludge...     

Active Biodegradable Cassava Starch Films Containing Sophorolipids Produced by Starmerella bombicola ATCC® 22214™

Journal of Polymers and the Environment - Sophorolipids are glycolipid biosurfactants produced by the yeast Starmerella bombicola. They have great potential for application in the food industry due...     

A Sustainable Perspective for Macadamia Nutshell Residues Revalorization by Green Composites Development

Journal of Polymers and the Environment - Macadamia is a nut widely used globally in food, personal hygiene products, and human health. After removing the nut, high amounts of the shell residual,...     

巴西中小企业的清洁生产挑战

微型、小型和中型企业创造了巴西的主要财富.但是这些企业却难以遵守环境法律.在这种情况下,清洁生产意义重大;它使得应用简便、廉价、持续的解决方案帮助小企业减少其环境影响、降低雇员的健康和安全风险成为可能.清洁生产战略通过把中心放在减少浪费和损耗上而改善环境条件.在实施清洁生产措施的同时,对一些措施的环境效率和经济可行性进行评估.采用最多的是良好的内务管理等简便措施.良好的内务管理包括业务参数的最优化、程序的标准化、改进买卖系统以及维护、信息和培训程序的最优化.巴西良好的内务管理战略所占的优势表明了对低成本解决方案的优先选择.     

Determining shark size from forensic analysis of bite damage

Bite damage patterns have long been used to estimate shark species and body size, with somewhat limited success. The lack of fit between damage patterns and shark size is partially due to variation in tooth size and shape within an individual. The ability to accurately predict body size from bite patterns is important for better understanding the ecological and behavioral underpinnings of shark bites/attacks on marine organisms, humans, and submarine equipment. To this end, we measured interdental distance (IDD) between the most labial teeth in the first six tooth files on both the upper and lower jaws, as well as the circumference of the portion of each jaw that bears teeth, for prepared jaw sets from fourteen shark species and regressed these data against total length. IDD is allometric as well as an accurate predictor of total length in all species examined, except Carcharhinus acronotus. Tooth-bearing circumference is also allometric and predictive of total length in all species. Though considerable overlap exists in IDD and circumference ranges among species for the total length ranges examined, Carcharodon carcharias and Isurus sp. can be differentiated from Carcharhinus limbatus, Carcharhinus brevipinna, and C. acronotus based on these values alone. When combined with knowledge of species-specific feeding behavior, geographic distribution, and habitat preferences, these simple measures from bite damage patterns allow quick, accurate assessment of shark size and potential species.     

Measuring complexity in three-trophic level systems

This essay is a trial on measuring complexity in a three-trophic level system by using a convex function of the informational entropy. The complexity measure defined here is compatible with the fact that real complexity lies between ordered and disordered states. Applying this measure to the data collected for two three-trophic level systems some hints about their organization are obtained.     

A system dynamics model for the management of the Manila clam, Ruditapes philippinarum (Adams and Reeve, 1850) in the Bay of Arcachon (France)

The Manila clam Ruditapes philippinarum (Adams and Reeve, 1850) is one of the mollusc species that, driven mainly by the shellfish market industry, has extended throughout the world, far beyond the limits of its original habitat. The Manila clam was introduced into France for aquaculture purposes, between 1972 and 1975. In France, this venerid culture became increasingly widespread and, since 1988, this species has colonised most of the embayments along the French Atlantic coast. In 2004, this development resulted in a fishery of ca. 520 t in Arcachon Bay.     

The fire frequency analysis branch of the pyrostatistics tree: sampling decisions and censoring in fire interval data

Statistical characterization of past fire regimes is important for both the ecology and management of fire-prone ecosystems. Survival analysis—or fire frequency analysis as it is often called in the fire literature—has increasingly been used over the last few decades to examine fire interval distributions. These distributions can be generated from a variety of sources (e.g., tree rings and stand age patterns), and analysis typically involves fitting the Weibull model. Given the widespread use of fire frequency analysis and the increasing availability of mapped fire history data, our goal has been to review and to examine some of the issues faced in applying these methods in a spatially explicit context. In particular, through a case study on the massive Cedar Fire in 2003 in southern California, we examine sensitivities of parameter estimates to the spatial resolution of sampling, point- and area-based methods for assigning sample values, current age surfaces versus historical intervals in generating distributions, and the inclusion of censored (i.e., incomplete) observations. Weibull parameter estimates were found to be roughly consistent with previous fire frequency analyses for shrublands (i.e., median age at burning of ~30–50 years and relatively low age dependency). Results indicate, however, that the inclusion or omission of censored observations can have a substantial effect on parameter estimates, far more than other decisions about specifics of sampling.