Browsing by Author "Guerreiro, Pedro M"
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- 16.P15. Branchial osmoregulatory response to salinity challenge in the Lusitanian toadfishPublication . Guerreiro, Pedro M; Laiz-Carrión, R.; Haond, Christophe; Modesto, Teresa; Fuentes, Juan; Mancera, J. M.; Canario, Adelino V. M.Halobatrachus didactylus, a marine teleost found in coastal lagoons and river estuaries is often exposed to important salinity changes. Despite its aglomerular kidney, it is able to survive in hypo-osmotic environments, likely via compensatory actions from gills and intestine. We aimed at evaluating the response of the branchial tissue of H. didactylus to salinity changes.
- Cold-induced growth arrest in gilthead sea bream Sparus aurata: metabolic reorganisation and recoveryPublication . Sánchez-Nuño, S.; Eroldogan, O. T.; Sanahuja, I.; Özşahniğlu, I.; Blasco, J.; Fernández-Borràs, J.; Fontanillas, R.; Guerreiro, Pedro M; Ibarz, A.There are currently no standard diets or practices to counteract or ameliorate the growth arrest and extremely poor feed conversion rates (FCR) in gilthead sea bream Sparus aurata caused by low water temperatures. The present study analysed the effects of reducing dietary lipid content from 18 to 14 % during a temperature fluctuation period. Temperature was gradually reduced from 22 degrees to 14 degrees C over a period of 5 d, and maintained at this low temperature for a further 45 d before gradual recovery over 7 d to 22 degrees C under controlled conditions, avoiding other stressors often present in cage culture conditions. Decreasing dietary lipid content at an elevated temperature (22 degrees C) did not significantly affect the standard growth rate or FCRs of the sea bream, indicating a possibility to reduce the dietary energy during the months before winter. Although cold-induced growth arrest and metabolic depression were unavoidable, a well-formulated, low-lipid diet adequately met the low energy demands at low temperatures. Analysis of plasma metabolites and liver enzyme activities demonstrated a reorganisation of liver metabolism, mainly in fish on a low-lipid diet. Recovery from low temperatures was delayed, with a higher dietary lipid content required for optimal liver condition, and mineral supplementation to maintain osmoregulation and bone formation. Our results provide useful information for fish producers and researchers, suggesting that dietary lipid contents should be reduced to allow fish to better cope with low temperatures, and that improved diets with higher lipid content are required for recovery from low temperatures.
- 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.
- Environmental salinity modifies mucus exudation and energy use in European Sea Bass JuvenilesPublication . Ordóñez-Grande, Borja; Guerreiro, Pedro M; Sanahuja, Ignasi; Fernández-Alacid, Laura; Ibarz, AntoniThe European sea bass (Dicentrarchus labrax) is a euryhaline marine teleost that can often be found in brackish and freshwater or even in hypersaline environments. Here, we exposed sea bass juveniles to sustained salinity challenges for 15 days, simulating one hypoosmotic (3‰), one isosmotic (12‰) and one hyperosmotic (50‰) environment, in addition to control (35‰). We analyzed parameters of skin mucus exudation and mucus biomarkers, as a minimally invasive tool, and plasma biomarkers. Additionally, Na+/K+ -ATPase activity was measured, as well as the gill mucous cell distribution, type and shape. The volume of exuded mucus increased significantly under all the salinity challenges, increasing by 130% at 50‰ condition. Significantly greater amounts of soluble protein (3.9 ± 0.6 mg at 50‰ vs. 1.1 ± 0.2 mg at 35‰, p < 0.05) and lactate (4.0 ± 1.0 µg at 50‰ vs. 1.2 ± 0.3 µg at 35‰, p < 0.05) were released, with clear energy expenditure. Gill ATPase activity was significantly higher at the extreme salinities, and the gill mucous cell distribution was rearranged, with more acid and neutral mucin mucous cells at 50‰. Skin mucus osmolality suggested an osmoregulatory function as an ion-trap layer in hypoosmotic conditions, retaining osmosis-related ions. Overall, when sea bass cope with different salinities, the hyperosmotic condition (50‰) demanded more energy than the extreme hypoosmotic condition.
- Genetic and molecular analysis of phosphorus homeostasis regulatory genes. A key nutrient for aquaculture sustainabilityPublication . Suarez-Bregua, P.; Torres-Nunez, E.; Prober, D.; Cerda-Reverter, J. M.; Guerreiro, Pedro M; Du, S. J.; Canestro, C.; Rotllant, J.
- Metabolic responses and resilience to environmental challenges in the sedentary Batrachoid Halobatrachus didactylus (Bloch & Schneider, 1801)Publication . Molina, Juan; Kunzmann, Andreas; Reis, João Pena; Guerreiro, Pedro MIn the context of climate change, warming of the seas and expansion of hypoxic zones are challenges that most species of fish are, or will be subjected to. Understanding how different species cope with these changes in their environment at the individual level can shed light on how populations and ecosystems will be affected. We provide first-time estimates on the metabolic rates, thermal, and oxygen-related limits for Halobatrachus didactylus, a coastal sedentary fish that lives in intertidal environments of the Northeast Atlantic. Using respirometry in different experimental designs, we found that this species is highly resistant to acute thermal stress (CTmax: 34.82 ± 0.66 °C) and acute hypoxia (Pcrit: 0.59–1.97 mg O2 L−1). We found size-specific differences in this stress response, with smaller individuals being more sensitive. We also quantified its aerobic scope and daily activity patterns, finding this fish to be extremely sedentary, with one of the lowest standard metabolic rates found in temperate fish (SMR: 14.96 mg O2 kg−1h−1). H. didactylus activity increases at night, when its metabolic rate increases drastically (RMR: 36.01 mg O2 kg−1h−1). The maximum metabolic rate of H. didactylus was estimated to be 67.31 mg O2 kg−1h−1, producing an aerobic scope of 52.35 mg O2 kg−1h−1 (77.8% increase). The metrics obtained in this study prove that H. didactylus is remarkably resilient to acute environmental variations in temperature and oxygen content, which might enable it to adapt to the extreme abiotic conditions forecasted for the world’s oceans in the near future.
- Modulation of pituitary response by dietary lipids and throughout a temperature fluctuation challenge in Gilthead Sea BreamPublication . Sánchez-Nuño, Sergio; Silva, Sandra; Guerreiro, Pedro M; Ordóñez-Grande, Borja; Sanahuja, Ignasi; Fernández-Alacid, Laura; Ibarz, AntoniLow temperatures provoke drastic reductions in gilthead sea bream (Sparus aurata) activity and nourishment, leading to growth arrest and a halt in production. However, scarce data exist concerning the implications of central core control during the cold season. The aim of this work was to study the effects of low temperature and recovery from such exposure on the pituitary activity of sea bream juveniles fed 18% or 14% dietary lipid. A controlled indoor trial was performed to simulate natural temperature fluctuation (22 ◦C to 14 ◦C to 22 ◦C). Meanwhile, we determined the regulatory role of the pituitary by analyzing the gene expression of some pituitary hormones and hormone receptors via qPCR, as well as plasma levels of thyroidal hormones. In response to higher dietary lipids, hormone pituitary expressions were up-regulated. Induced low temperatures and lower ingesta modulated pituitary function up-regulating GH and TSH and thyroid and glucocorticoid receptors. All these findings demonstrate the capacity of the pituitary to recognize both external conditions and to modulate its response accordingly. However, growth, peripheral tissues and metabolism were not linked or connected to pituitary function at low temperatures, which opens an interesting field of study to interpret the hypothalamus–pituitary–target axis during temperature fluctuations in fish.
- Proteomics and the search for welfare and stress biomarkers in animal production in the one-health contextPublication . Marco-Ramell, A.; de Almeida, A. M.; Cristobal, S.; Guerreiro, Pedro M; Roncada, P.; Bassols, A.Stress and welfare are important factors in animal production in the context of growing production optimization and scrutiny by the general public. In a context in which animal and human health are intertwined aspects of the one-health concept it is of utmost importance to define the markers of stress and welfare. These are important tools for producers, retailers, regulatory agents and ultimately consumers to effectively monitor and assess the welfare state of production animals. Proteomics is the science that studies the proteins existing in a given tissue or fluid. In this review we address this topic by showing clear examples where proteomics has been used to study stress-induced changes at various levels. We adopt a multi-species (cattle, swine, small ruminants, poultry, fish and shellfish) approach under the effect of various stress inducers (handling, transport, management, nutritional, thermal and exposure to pollutants) clearly demonstrating how proteomics and systems biology are key elements to the study of stress and welfare in farm animals and powerful tools for animal welfare, health and productivity.
- Proteomics in food: Quality, safety, microbes, and allergensPublication . Piras, Cristian; Roncada, Paola; Guerreiro, Pedro M; Bonizzi, Luigi; Soggiu, AlessioFood safety and quality and their associated risks pose a major concern worldwide regarding not only the relative economical losses but also the potential danger to consumer's health. Customer's confidence in the integrity of the food supply could be hampered by inappropriate food safety measures. A lack of measures and reliable assays to evaluate and maintain a good control of food characteristics may affect the food industry economy and shatter consumer confidence. It is imperative to create and to establish fast and reliable analytical methods that allow a good and rapid analysis of food products during the whole food chain. Proteomics can represent a powerful tool to address this issue, due to its proven excellent quantitative and qualitative drawbacks in protein analysis. This review illustrates the applications of proteomics in the past few years in food science focusing on food of animal origin with some brief hints on other types. Aim of this review is to highlight the importance of this science as a valuable tool to assess food quality and safety. Emphasis is also posed in food processing, allergies, and possible contaminants like bacteria, fungi, and other pathogens.
- Social organization and endocrine profiles of Australoheros facetus, an exotic freshwater fish in southern PortugalPublication . Baduy, F.; Silva, FBV; Guerreiro, Pedro M; Canario, A.V.M.; L. Saraiva, JoãoAustraloheros facetus is a neotropical cichlid and an exotic species in the Guadiana and Odelouca basins (Southern Portugal). In this research, we aimed to characterize the main behavioural patterns and circulating hormones, 17 beta-estradiol (E-2) for females, and testosterone, 11-ketotestosterone (11KT) and cortisol for both sexes, during the formation of social groups, a crucial step in the life-history of A. facetus. A pair-breeding strategy with territorial behaviour and aggressive interactions was found, with a positive correlation between dominance and size for both sexes. There were no significant differences between non-territorial and territorial individuals in the baseline levels of hormones, but 11KT was higher in males when they became territorial, as E-2 for territorial females, while there was no clear pattern for testosterone. In contrast, cortisol was higher in non-territorial males and correlated negatively with social dominance. These results suggest that size is the main driver for social dominance and that formation of stable hierarchies result in higher circulating 11KT and lowers stress in territorial males. Related to A. facetus' behaviour, aggressiveness and biparental care may be an advantage during the invasion process of A. facetus, facilitating colonization of new habitats.