Browsing by Author "Cabral, Henrique"
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- Does predation exacerbate the risk of endosymbiont loss in heat stressed hermatypic corals? molecular cues provide insights into species-specific health outcomes in a multi-stressor oceanPublication . Madeira, Carolina; Dias, Marta; Ferreira, Ana; Gouveia, Raúl; Cabral, Henrique; Diniz, Mário S.; Vinagre, CatarinaOcean warming has been a major driver of coral reef bleaching and mass mortality. Coupled to other biotic pressures, corals' ability for acclimatization and adaptation may become compromised. Here, we tested the combined effects of warming scenarios (26, 30, and 32 degrees C) and predation (wound vs. no wound) in coral health condition (paleness, bleaching, and mortality), cellular stress responses (heat shock protein 70 kDa Hsp70, total ubiquitin Ub, and total antioxidant capacity TAC), and physiological state (integrated biomarker response index, IBR) of seven Scleractinian coral species, after being exposed for 60 days. Results show that although temperature was the main factor driving coral health condition, thermotolerant species (Galaxea fascicularis, Psammocora contigua, and Turbinaria reniformis) displayed increased paleness, bleaching, and mortality in predation treatments at high temperature, whereas thermosensitive species (Acropora tenuis, Echinopora lamellosa, and Montipora capricornis brown and green morphotypes) all died at 32 degrees C, regardless of predation condition. At the molecular level, results show that there were significant main and interactive effects of species, temperature, and predation in the biomarkers assessed. Temperature affected Hsp70, Ub, and TAC, evidencing the role of protein folding and turnover, as well as reactive oxygen species scavenging in heat stress management. Predation increased Hsp70 and Ub, suggesting the activation of the pro-phenoloxidase system and cytokine activity, whereas the combination of both stressors mainly affected TAC during moderate stress and Ub under severe stress, suggesting that redox balance and defense of homeostasis are crucial in tissue repair at high temperature. IBR levels showed an increasing trend at 32 degrees C in predated coral fragments (although non-significant). We conclude that coral responses to the combination of high temperature and predation pressure display high inter-species variability, but these stressors may pose a higher risk of endosymbiont loss, depending on species physiology and stress intensity.
- Effect of copper exposure on growth, condition indices and biomarker response in juvenile sole Solea senegalensisPublication . Fonseca, Vanessa; Serafim, Angela; Company, Rui; Bebianno, Maria João; Cabral, HenriqueJuvenile Solea senegalensis were exposed to different concentrations of waterborne copper (Cu) for 15 days ill static conditions with continuous aerated artificial salt water at 20 degrees C (+/- 0.8 degrees C with a normal photoperiod (10 h/14 h light/dark) and daily feeding. Several measures of exposure and effects were determined: 1) biomarkers - metallothioneins and lipid peroxidation level; 2) mass indices - growth rate and morphometric condition indices; and 3) biochemical condition indices - RNA:DNA ratio and lipid and protein content in fish tissues. Copper exposure triggered the response of the biomarkers and resulted in reduced growth and condition (RNA:DNA and lipid content), but the morphometric indices did not vary. The physiological costs of Cu contamination on condition Suggested that lipid reserves were allocated as an energy Source to enable exposed fish to respond to Cu toxicity as well as to maintain positive growth rates and protein synthesis throughout the experiment, although with lower growth rates than the control fish. This study showed the importance of selecting suitable biomarkers according to contaminant source, fish Species and their life-history stage. In addition, the use of several biomarkers of exposure, growth and specific condition indices call improve fish health determination and should be considered in evaluations of the effects of environmental contaminants on fish.
- Ichthyofauna of the Selvagens Islands. Do small coastal areas show high species richness in the northeastern Atlantic?Publication . Almada, Frederico; Abecasis, D.; Villegas-Ríos, David; Henriques, Sofia; Pais, Miguel P.; Batista, Marisa; Horta e Costa, Barbara; Martins, Joana; Tojeira, Inês; Rodrigues, Nuno Vasco; Araújo, Ricardo; Souto, Miguel; Alonso, Hany; Falcón, Jesús M.; Henriques, Filipe; Catry, Paulo; Cabral, Henrique; Biscoito, Manuel; Almada, Vítor C.The Selvagens Islands are located in the northeastern Atlantic between the Canary Islands and Madeira Island. As a result of their small size, remote location and harsh sea conditions only a few studies have been conducted to describe their marine species diversity. We were able to identify 29 new coastal fish species, an increase of 33% in the ichthyofauna described for these islands (n = 88). There is a prevalence of species with tropical affinities and only 2.3% (n = 2) are endemic to Macaronesia. Considered a stepping-stone colonization vector from the nearest continental shore, as proposed by other authors for this region, the Selvagens Islands host 34.1% of the ichthyofauna described for the much larger Canary Islands (nspecies = 258, submerged area nSelvagensIs. = 2.3%) and 47.3% of the ichthyofauna described for the more distantly located Madeira Island (nspecies = 186, submerged area nSelvagensIs. = 17.9%). Interestingly, 6.8% (n = 6) of the species failed to bridge the gap between the Selvagens Islands and Madeira Island. Data collected so far showed no trend toward an increasing number of species with high dispersal capability. The Selvagens Islands are an example of a high coastal species diversity occurring even in very small areas of the northeastern Atlantic Ocean.
- Ready for co-management? Portuguese artisanal octopus fishers preferences for management and knowledge about the resourcePublication . Silva, Priscila; Cabral, Henrique; Rangel, Mafalda; Pereira, João; Pita, CristinaIn Portugal, the common octopus (Octopus vulgaris) dominates the total catches and landings from small scale fisheries. The small-scale fisheries have been targeting the common octopus for a long time and it is consistently one of the most important commercial fishing resources in the country. Questionnaires were conducted in 13 fishing ports in the south and southwest coasts of Portugal, from November 2014 to December 2016, to explore octopus artisanal fishers’ preferences for management and their knowledge about the biology and ecology of octopus. The survey revealed that fishers are generally not satisfied with the current management of the octopus fisheries. Some differences in preferences for management were found between regions, but in general, fishers strongly supported biological closures and local management plans developed by themselves. Fishers seemed to be interest in being more involved in the decision-making process, but only seem to have a moderate knowledge about the biology and ecology of the resource they exploit. A greater involvement of fishers in decision-making process will contribute to increase their awareness and knowledge about the resource, their receptivity to and acceptance of management measures, as well as increase their feeling of responsibility towards, and ownership of the resource.