163 resultados para Fish nutrition


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Protogynous sequential hermaphroditism is very common in marine fish. Despite a large number of studies on various aspects of sequential hermaphroditism in fish, the relationship between body shape and colour during growth in dichromatic species has not been assessed. Using geometric morphometrics, the present study explores the relationship between growth, body shape and colouration in Coris julis (L. 1758), a small protogynous labrid species with distinct colour phases. Results show that body shape change during growth is independent of change in colour phase, a result which can be explained by the biology of the species and by the social control of sex change. Also, during growth the body grows deeper and the head has a steeper profile. It is hypothesized that a deeper body and a steeper profile might have a function in agonistic interactions between terminal phase males and that the marked chromatic difference between colour phases allows the lack of strict interdependence of body shape and colour during growth.

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Gut bacterial communities are now known to influence a range of fitness related aspects of organisms. But how different the microbial community is in closely related species, and if these differences can be interpreted as adaptive is still unclear. In this study we compared microbial communities in two sets of closely related sympatric crater lake cichlid fish species pairs that show similar adaptations along the limnetic-benthic axis. The gut microbial community composition differs in the species pair inhabiting the older of two crater lakes. One major difference, relative to other fish, is that in these cichlids that live in hypersaline crater lakes, the microbial community is largely made up of Oceanospirillales (52.28%) which are halotolerant or halophilic bacteria. This analysis opens up further avenues to identify candidate symbiotic or co-evolved bacteria playing a role in adaptation to similar diets and life-styles or even have a role in speciation. Future functional and phylosymbiotic analyses might help to address these issues.

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In fisheries managed using individual transferable quotas (ITQs) it is generally assumed that quota markets are well-functioning, allowing quota to flow on either a temporary or permanent basis to those able to make best use of it. However, despite an increasing number of fisheries being managed under ITQs, empirical assessments of the quota markets that have actually evolved in these fisheries remain scarce. The Queensland Coral Reef Fin-Fish Fishery (CRFFF) on the Great Barrier Reef has been managed under a system of ITQs since 2004. Data on individual quota holdings and trades for the period 2004-2012 were used to assess the CRFFF quota market and its evolution through time. Network analysis was applied to assess market structure and the nature of lease-trading relationships. An assessment of market participants’ abilities to balance their quota accounts, i.e., gap analysis, provided insights into market functionality and how this may have changed in the period observed. Trends in ownership and trade were determined, and market participants were identified as belonging to one out of a set of seven generalized types. The emergence of groups such as investors and lease-dependent fishers is clear. In 2011-2012, 41% of coral trout quota was owned by participants that did not fish it, and 64% of total coral trout landings were made by fishers that owned only 10% of the quota. Quota brokers emerged whose influence on the market varied with the bioeconomic conditions of the fishery. Throughout the study period some quota was found to remain inactive, implying potential market inefficiencies. Contribution to this inactivity appeared asymmetrical, with most residing in the hands of smaller quota holders. The importance of transaction costs in the operation of the quota market and the inequalities that may result are discussed in light of these findings

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Chlamydial infections of fish are emerging as an important cause of disease in new and established aquaculture industries. To date, epitheliocystis, a skin and gill disease associated with infection by these obligate intracellular pathogens, has been described in over 90 fish species, including hosts from marine and fresh water environments. Aided by advances in molecular detection and typing, recent years have seen an explosion in the description of these epitheliocystis-related chlamydial pathogens of fish, significantly broadening our knowledge of the genetic diversity of the order Chlamydiales. Remarkably, in most cases, it seems that each new piscine host studied has revealed the presence of a phylogenetically unique and novel chlamydial pathogen, providing researchers with a fascinating opportunity to understand the origin, evolution and adaptation of their traditional terrestrial chlamydial relatives. Despite the advances in this area, much still needs to be learnt about the epidemiology of chlamydial infections in fish if these pathogens are to be controlled in farmed environments. The lack of in vitro methods for culturing of chlamydial pathogens of fish is a major hindrance to this field. This review provides an update on our current knowledge of the taxonomy and diversity of chlamydial pathogens of fish, discusses the impact of these infections on the health, and highlights further areas of research required to understand the biology and epidemiology of this important emerging group of fish pathogens of aquaculture species.

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Purpose Malnutrition is a very common problem in oncology patients and is associated with many negative consequences including poorer prognosis, quality of life and survival. However, malnutrition in oncology patients is often overlooked although there is growing evidence showing that it can be prevented or reduced through nutrition intervention. This paper aims to provide an updated review on the effectiveness of different nutrition intervention approaches on nutrition status outcomes in oncology patients. Methods Randomised controlled trials (RCTs) published between 1994 and 2014 which examined the effects of nutrition intervention approaches—in particular, nutrition counselling (NC), oral nutrition supplements (ONS) and tube feeding (TF)—on nutrition status outcomes of oncology patients were identified and reviewed. Results Thirteen papers from 11 RCTs with a total of 1077 participants were included. The intervention approaches included NC (four studies), NC + ONS (five studies), ONS (three studies) and TF (three studies). The various results suggest that NC with or without ONS was associated with consistent improvements in several nutrition status outcomes. On the other hand, ONS and TF were associated with inconsistent improvements in few aspects of nutrition status outcomes. Conclusions The referral of oncology patients for NC is recommended given the strong evidence of its beneficial effects on the prevention and reduction of malnutrition. Other forms of nutrition support including ONS and TF may then be included if deemed suitable and necessary for the individual.

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The fate of two popular antibiotics, oxytetracycline and oxolinic acid, in a fish pond were simulated using a computational model. The VDC model, which is designed based on a model for predicting pesticide fate and transport in paddy fields, was modified to take into account the differences between the pond and the paddies as well as those between the fish and the rice plant behaviors. The pond conditions were set following the typical practice in South East Asia aquaculture. The two antibiotics were administered to the animal in the pond through medicated feed during a period of 5 days as in actual practice. Concentrations of oxytetracycline in pond water were higher than those of oxolinic acid at the beginning of the simulation. Dissipation rate of oxytetracycline is also higher as it is more readily available for degradation in the water. For the long term, oxolinic acid was present at higher concentration than oxytetracycline in pond water as well as pond sediment. The simulated results were expected to be conservative and can be useful for the lower tier assessment of exposure risk of veterinary medicine in aquaculture industry but more data are needed for the complete validation of the model.

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Natural resource managers and scientists focus on the behaviour of individual recreational fishers to understand environmental problems associated with this leisure activity. They do this in an effort to identify ways to change attitudes in order to facilitate environmentally friendly choices. This applied use of ABC psychology (attitude, behaviour, choice) has not delivered the expected results. This article offers a different approach by investigating an emergent practice in diverse fishing communities, rather than looking to the responsibility of the individual recreational fisher. Using practice theory, I trace the change from take-all to catch-and-release fishing in Australia by analysing the texts of celebrity fisher Rex Hunt, who is an advocate for releasing fish. I combine this with oral history testimony from a sample of recreational fishers from the broader Australian community to show how change happened. The practice of catch-and-release fishing emerged through the combination of sociotechnical and historically specific elements present in popular culture, including the media. Paying attention to the way different elements catalyse provides a rich account of the changing modes of sustainability in recreational fishing communities.

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Metabolic programming during the perinatal period as a consequence of early nutrition is an emerging area of great interest. This concept is known as the "fetal origins of adult disease" theory (1). Numerous epidemiological studies published over the past 20 years or so have suggested that small body size at birth and during infancy and, more specifically, intrauterine growth retardation are associated later in life with lowered cognitive performance and increased rates of coronary heart disease and its major biological risk factors, ie, raised blood pressure, insulin resistance, coronary artery disease, and abnormalities in lipid metabolism. The molecular mechanisms that govern this phenomenon in humans, however, are unknown and need to be elucidated.

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Dieting and non-dieting are two contrasting approaches to the management of overweight/obesity, but less is known about why people follow non-dieting approaches and how these approaches are associated with health and nutrition status indicators. This thesis enables a greater understanding of why dieting and non-dieting approaches are adopted and provides insight into whether one approach is more favourably associated with nutrition and health status indicators. The findings of this thesis will be useful for clinicians who wish to encourage dieting or non-dieting approaches in their clients and for researchers wishing to understand how best to address overweight and obesity.

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School canteens represent Australia's largest take-away food outlet. With changes in lifestyles and family roles, canteens are used increasingly as a source of food for students. The nutritional quality of foods offered can have a significant impact on the nutritional status of students both now, and in the future. The Australian Nutrition Foundation has been developing its work in the field of school canteens over the past six years. Perhaps its most significant contribution to improving the health of canteens has been the development of the "Food Selection Guidelines for Children and Adolescents". These Guidelines are used to assess foods most suitable for sale in school canteens and for purchasing food in boarding schools. Products meeting the Guidelines are added to the ANF Registered Product List which school canteens and kitchens use as a type of "buying guide". This project has been successfully piloted in Queensland and this year has been expanded to a national campaign.

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Objective To examine the impact of efforts to improve nutrition on the Anangu Pitjantjatjara Yankunytjatjara (APY) Lands from 1986, especially in Mai Wiru stores. Methods Literature was searched in a systematic manner. In 2012, the store-turnover method was used to quantify dietary intake of the five APY communities that have a Mai Wiru (good food) store. Results were compared with those available from 1986. Prices of a standard market basket of basic foods, implementation of nutrition policy requirements and healthy food checklists were also assessed in all seven APY community stores from 2008 and compared with available data from 1986. Results Despite concerted efforts and achievements decreasing intake of sugar and increasing the availability and affordability of healthy foods, particularly fruit and vegetables, and consequent improvements in some nutrient indicators, the overall effect has been a decrease in diet quality as indicated primarily by the increased supply and proportion of energy intake from discretionary foods, particularly sugar-sweetened beverages, convenience meals and take-away foods. Conclusions The study findings reinforce the notion that, in the absence of supportive regulation and market intervention, adequate and sustained resources are required to improve nutrition and prevent diet-related chronic disease on the APY Lands. Implications This study also provides insights into food supply/security issues affecting other remote Aboriginal communities and wider Australia.

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Reducing unwanted trawl bycatch is actively encouraged in Australia, particularly in prawn trawl fisheries. We tested the performance of a Bycatch Reduction Device, the Yarrow Fisheye, during two periods of commercial fishing operations in Australia's Northern Prawn Fishery, by comparing the catches of paired treatment and control nets. We compared the catch weights of the small fish and invertebrate bycatch, and the commercially important tiger prawns, from 42 trawls in 2002. The Yarrow Fisheye reduced the weight of small bycatch by a mean of 22.7%, with no loss of tiger prawn. We also compared the numbers of seasnakes caught in 41 and 72 trawls during the spring trawling seasons of 2004 and 2005, respectively. The Yarrow Fisheye reduced the catches by a mean of 43.3%. Flume-tank tests of the Yarrow Fisheye showed that this device created a slow water-flow region extending over 2 m downstream from its position in the net, and close to where the catch accumulates. Finfish and seasnakes may be exploiting this slow water-flow region to escape via the eye, Although the reductions in fish and seasnake bycatch were excellent, we think they could be further improved by relating differences in fisheye position and localised water displacements, to design and rigging changes.