Application of passive sampling to characterise the fish exometabolome

The endogenous metabolites excreted by organisms into their surrounding environment, termed the exometabolome, are important for many processes including chemical communication. In fish biology, such metabolites are also known to be informative markers of physiological status. While metabolomics is increasingly used to investigate the endogenous biochemistry of organisms, no non-targeted studies of the metabolic complexity of fish exometabolomes have been reported to date. In environmental chemistry, Chemcatcher® (Portsmouth, UK) passive samplers have been developed to sample for micro-pollutants in water. Given the importance of the fish exometabolome, we sought to evaluate the capability of Chemcatcher® samplers to capture a broad spectrum of endogenous metabolites excreted by fish and to measure these using non-targeted direct infusion mass spectrometry metabolomics. The capabilities of C18 and styrene divinylbenzene reversed-phase sulfonated (SDB-RPS) Empore™ disks for capturing non-polar and polar metabolites, respectively, were compared. Furthermore, we investigated real, complex metabolite mixtures excreted from two model fish species, rainbow trout (Oncorhynchus mykiss) and three-spined stickleback (Gasterosteus aculeatus). In total, 344 biological samples and 28 QC samples were analysed, revealing 646 and 215 m/z peaks from trout and stickleback, respectively. The measured exometabolomes were principally affected by the type of Empore™ (Hemel Hempstead, UK) disk and also by the sampling time. Many peaks were putatively annotated, including several bile acids (e.g., chenodeoxycholate, taurocholate, glycocholate, glycolithocholate, glycochenodeoxycholate, glycodeoxycholate). Collectively these observations show the ability of Chemcatcher® passive samplers to capture endogenous metabolites excreted from fish

Non-invasive measurement of steroids in fish-holding water 1327

Summary Fish behaviourists are increasingly turning to non-invasive measurement of steroid hormones in holding water, as opposed to blood plasma. When some of us met at a workshop in Faro, Portugal, in September, 2007, we realised that there were still many issues concerning the application of this procedure that needed resolution, including: Why do we measure release rates rather than just concentrations of steroids in the water? How does one interpret steroid release rates when dealing with fish of different sizes? What are the merits of measuring conjugated as well as free steroids in water? In the 'static' sampling procedure, where fish are placed in a separate container for a short period of time, does this affect steroid releaseand, if so, how can it be minimised? After exposing a fish to a behavioural stimulus, when is the optimal time to sample? What is the minimum amount of validation when applying the procedure to a new species? The purpose of this review is to attempt to answer these questions and, in doing so, to emphasize that application of the non-invasive procedure requires more planning and validation than conventional plasma sampling. However, we consider that the rewards justify the extra effort

Application of the reproductive behaviour of the three-spined stickleback in the detection of environmental anti-androgens

Endocrine disrupting chemicals (EDCs) released into the environment are known to cause adverse effects in many aquatic species, including fish. So far, the bulk of the literature has dealt with the role of xenoestrogens in fish feminisation whilst the potential effects of xenoandrogens are less studied.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Summary of the in vivo stickleback tests aimed to be part of the official OECD guidelines for endocrine disruptor testing

The potential of developing a biomarker for androgens in the three-spined stickleback (via the kidney glue protein that breeding males use to construct a nest) was recognised 10 years ago. As a consequence, under the UK EDMAR programme an ELISA for the only known so far androgen-regulated protein in fish, the stickleback glue spiggin, was developed and validated. More recently the stickleback assay was modified in two different ways to detect anti-androgens, a group of EDCs that poses an increasing risk to the aquatic environment as the in vitro data obtained from two nationwide surveys of final sewage effluents suggest. Importantly, the stickleback is present in Europe (and across all of the North hemisphere) and can bring together lab and field studies providing a sound basis for environmental risk assessment. To this end, the UK (Defra CN) has financed three research programmes that underpinned the background and validation data requirements that could lead to the inclusion of the stickleback as a recommended species for EDCs screening. Here we present the outcomes of this research and provide an update of the current state of fish test guidelines for EDCs. In addition we will be referring to a new project, funded by the National Centre of 3Rs, UK and is aiming to validate the fish sexual development test (another OECD guideline line under development) using the stickleback. The presence of a genetic sex marker in the stickleback (as in the medaka) has the potential of reducing the number of fish needed for this test because genetic sex (as opposed to phenotypic) can be assigned

Exercise-induced Growth Hormone Secretion in the Assessment of Growth Hormone Deficiency in Adult Individuals

The role of exercise testing in the assessment of GH deficiency (GHD) in adult patients is currently unclear. This study aimed at evaluating the diagnostic value of exercise-induced GH levels in the detection of severe GHD in adult patients

How chronic anthropogenic noise can affect wildlife communities

Anthropogenic noise is a major pollutant in terrestrial and aquatic ecosystems. Since the industrial revolution, human activities have become increasingly noisy, leading to both acute and chronic disturbance of a wide variety of animals. Chronic noise exposure can affect animals over their lifespan, leading to changes in species interactions and likely altering communities. However, the community-level impacts of chronic noise are not well-understood, which impairs our ability for effective mitigation. In this review, we address the effects of chronic noise exposure on communities and explore possible mechanisms underlying these effects. The limited studies on this topic suggest that noise can affect communities by changing the behavior and/or physiology of species in a community, which results in direct or knock-on consequences for other species in the ecosystem. Major knowledge gaps remain due to the logistically complex and financially expensive nature of the long-term studies needed to address these questions. By identifying these gaps and suggesting approaches to answer them, we provide a road map toward mitigating the effects of a noisy world

How chronic anthropogenic noise can affect wildlife communities

Anthropogenic noise is a major pollutant in terrestrial and aquatic ecosystems. Since the industrial revolution, human activities have become increasingly noisy, leading to both acute and chronic disturbance of a wide variety of animals. Chronic noise exposure can affect animals over their lifespan, leading to changes in species interactions and likely altering communities. However, the community-level impacts of chronic noise are not well-understood, which impairs our ability for effective mitigation. In this review, we address the effects of chronic noise exposure on communities and explore possible mechanisms underlying these effects. The limited studies on this topic suggest that noise can affect communities by changing the behavior and/or physiology of species in a community, which results in direct or knock-on consequences for other species in the ecosystem. Major knowledge gaps remain due to the logistically complex and financially expensive nature of the long-term studies needed to address these questions. By identifying these gaps and suggesting approaches to answer them, we provide a road map toward mitigating the effects of a noisy world.</p