Browsing by Author "Wilson, Jonathan M."
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- Conservation physiology of marine fishes: state of the art and prospects for policyPublication . McKenzie, David J.; Axelsson, Michael; Chabot, Denis; Claireaux, Guy; Cooke, Steven J.; Corner, Richard A.; De Boeck, Gudrun; Domenici, Paolo; Guerreiro, Pedro M; Hamer, Bojan; Jørgensen, Christian; Killen, Shaun S.; Lefevre, Sjannie; Marras, Stefano; Michaelidis, Basile; Nilsson, Göran E.; Peck, Myron A.; Perez-Ruzafa, Angel; Rijnsdorp, Adriaan D.; Shiels, Holly A.; Steffensen, John F.; Svendsen, Jon C.; Svendsen, Morten B. S.; Teal, Lorna R.; van der Meer, Jaap; Wang, Tobias; Wilson, Jonathan M.; Wilson, Rod W.; Metcalfe, Julian D.The state of the art of research on the environmental physiology of marine fishes is reviewed from the perspective of how it can contribute to conservation of biodiversity and fishery resources. A major constraint to application of physiological knowledge for conservation of marine fishes is the limited knowledge base; international collaboration is needed to study the environmental physiology of a wider range of species. Multifactorial field and laboratory studies on biomarkers hold promise to relate ecophysiology directly to habitat quality and population status. The 'Fry paradigm' could have broad applications for conservation physiology research if it provides a universal mechanism to link physiological function with ecological performance and population dynamics of fishes, through effects of abiotic conditions on aerobic metabolic scope. The available data indicate, however, that the paradigm is not universal, so further research is required on a wide diversity of species. Fish physiologists should interact closely with researchers developing ecological models, in order to investigate how integrating physiological information improves confidence in projecting effects of global change; for example, with mechanistic models that define habitat suitability based upon potential for aerobic scope or outputs of a dynamic energy budget. One major challenge to upscaling from physiology of individuals to the level of species and communities is incorporating intraspecific variation, which could be a crucial component of species' resilience to global change. Understanding what fishes do in the wild is also a challenge, but techniques of biotelemetry and biologging are providing novel information towards effective conservation. Overall, fish physiologists must strive to render research outputs more applicable to management and decision-making. There are various potential avenues for information flow, in the shorter term directly through biomarker studies and in the longer term by collaborating with modellers and fishery biologists.
- Extensive gene loss parallels kidney aglomerulism in SyngnathidaePublication . Pinto, Bernardo; Machado, André M.; Cordeiro, J. Miguel; Kolbadinezhad, Salman Malakpour; Fonseca, Elza; Andrade, Jose; Palma, Jorge; Ruivo, Raquel; Monteiro, Nuno; Wilson, Jonathan M.; Castro, L. Filipe C.The eccentric seahorses, seadragons, pipehorses and pipefishes (Syngnathidae) have an aglomerular kidney1. Here, we show that nephron genes2 conserved in Bilateria are secondarily eroded/deleted in Syngnathidae genomes. A transcriptome enrichment analysis suggests the predominance of excretion processes in the Syngnathidae kidney. In a lineage where crypsis and idleness are tightly associated, we propose that aglomerulism evolved as an energy-saving strategy.
- Freshening effect on the osmotic response of the Antarctic spiny plunderfish Harpagifer antarcticusPublication . Vargas-Chacoff, Luis; Dann, Francisco; Paschke, Kurt; Oyarzun-Salazar, Ricardo; Nualart, Daniela; Martinez, Danixa; Wilson, Jonathan M.; Guerreiro, Pedro; Navarro, Jorge M.Global warming is having a significant impact around the world, modifying environmental conditions in many areas, including in zones that have been thermally stable for thousands of years, such as Antarctica. Stenothermal sedentary intertidal fish species may suffer due to warming, notably if this causes water freshening from increased freshwater inputs. Acute decreases in salinity, from 33 down to 5, were used to assess osmotic responses to environmental salinity fluctuations in Antarctic spiny plunderfish Harpagifer antarcticus, in particular to evaluate if H. antarcticus is able to cope with freshening and to describe osmoregulatory responses at different levels (haematological variables, muscle water content, gene expression, NKA activity). H. antarcticus were acclimated to a range of salinities (33 as control, 20, 15, 10 and 5) for 1 week. At 5, plasma osmolality and calcium concentration were both at their lowest, while plasma cortisol and percentage muscle water content were at their highest. At the same salinity, gill and intestine Na+-K+-ATPase (NKA) activities were at their lowest and highest, respectively. In kidney, NKA activity was highest at intermediate salinities (15 and 10). The salinity-dependent NKA mRNA expression patterns differed depending on the tissue. Marked changes were also observed in the expression of genes coding membrane proteins associated with ion and water transport, such as NKCC2, CFTR and AQP8, and in the expression of mRNA for the regulatory hormone prolactin (PRL) and its receptor (PRLr). Our results demonstrate that freshening causes osmotic imbalances in H. antarcticus, apparently due to reduced capacity of both transport and regulatory mechanisms of key organs to maintain homeostasis. This has implications for fish species that have evolved in stable environmental conditions in the Antarctic, now threatened by climate change.