Browsing by Author "Calado, Ricardo"
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- 3D chemoecology and chemotaxonomy of corals using fatty acid biomarkers: Latitude, longitude and depthPublication . Figueiredo, Cátia; Baptista, Miguel; Rosa, Inês; Lopes, Ana Rita; Dionísio, Gisela; Rocha, Rui J.M.; Cruz, Igor C.S.; Kikuchi, Ruy K.P.; Simões, Nuno; Leal, Miguel Costa; Tojeira, Inês; Bandarra, Narcisa; Calado, Ricardo; Rosa, RuiWith the objective of uncovering differences in the fatty acid (FA) composition of hexa- and octocorals from different climatic zones (equatorial, subtropical and tropical) and distinct habitats (e.g. rock and coral reefs; intertidal to deep-sea environments), the FA composition of 36 hexa- and octocoral species (132 specimens) was analysed (including the first characterization of organisms from the order Zoantharia and deep-sea gorgonians). PCA was applied in a FA matrix of the ten major PUFAs to detect differences among coral groups. Fatty acid profile analysis confirmed that C24 polyunsaturated FAs are suitable chemotaxonomic biomarkers to separate hexa- and octocorals. The polyunsaturated FA 22:6n-3 was identified as a useful biomarker to distinguish between zoantharians and scleractinians. Also, we discuss the role of food availability (type of phytoplankton assemblage) in relation to autotrophic carbon significance and in the establishment of FA profiles of octocorals from the West and East coasts of the Atlantic Ocean. Furthermore, we show that the occurrence of high levels of primary productivity hinder the use of FA profiles to distinguish between zooxanthellate and azooxanthellate octocorals. Finally, we present and discuss the particular traits of the FA profile of deep-sea gorgonians while comparing it with that of shallow species.
- Bacterial communities from corals cultured ex situ remain stable under different light regimes — Relevance for in toto aquaculturePublication . Pimentel, Tânia; Rocha, Rui J.M.; Rosa, Rui; Soares, Amadeu M.V.M.; Gomes, Newton C.M.; Leal, Miguel C.; Calado, RicardoMicrobial communities associated with corals are an important source of bioactive metabolites with great potential for drug discovery. However, culturing these symbiotic microbes is extremely complex and often impossible. In toto coral aquaculture performed ex situ (the culture of the holobiont–cnidarian host and associated microorganisms) has been suggested as a potential solution to solve the constraints of supplying metabolite biomass to fuel the drug discovery pipeline. In the present study we investigated if coral fragmentation and different light intensities (photosynthetically active radiation (PAR) of 50, 80 and 120 μmol quanta m− 2 s− 1) significantly affect the diversity and structure of the microbial communities present in the leather coral Sarcophyton cf. glaucum assessed through polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). The diversity and structure of the bacterial communities present in mother colonies and fragments stocked under identical conditions remained stable two months post fragmentation, as well as between coral fragments stocked under different PAR intensities. The observed stability in the microbial community supports that in toto coral aquaculture may be a suitable option to produce metabolite biomass from symbiotic microorganisms. The possibility to employ a low PAR intensity to grow coral fragments without significantly affecting their microbial diversity and structure is likely to decrease aquaculture production costs and improve its economic viability.
- Climate change impacts on the distribution of coastal lobstersPublication . Boavida-Portugal, Joana; Rosa, Rui; Calado, Ricardo; Pinto, Maria; Boavida-Portugal, Inês; Araújo, Miguel B.; Guilhaumon, FrançoisCoastal lobsters support important fisheries all over the world, but there is evidence that climate-induced changes may jeopardize some stocks. Here we present the first global forecasts of changes in coastal lobster species distribution under climate change, using an ensemble of ecological niche models (ENMs). Global changes in richness were projected for 125 coastal lobster species for the end of the century, using a stabilization scenario (4.5 RCP). We compared projected changes in diversity with lobster fisheries data and found that losses in suitable habitat for coastal lobster species were mainly projected in areas with high commercial fishing interest, with species projected to contract their climatic envelope between 40 and 100%. Higher losses of spiny lobsters are projected in the coasts of wider Caribbean/Brazil, eastern Africa and Indo-Pacific region, areas with several directed fisheries and aquacultures, while clawed lobsters are projected to shifts their envelope to northern latitudes likely affecting the North European, North American and Canadian fisheries. Fisheries represent an important resource for local and global economies and understanding how they might be affected by climate change scenarios is paramount when developing specific or regional management strategies.
- Cuttlefish capsule: An effective shield against contaminants in the wildPublication . Rosa, Inês; Raimundo, Joana; Lopes, Vanessa; Brandão, Cláudio; Couto, Ana; Santos, Catarina; Cabecinhas, Adriana S.; Cereja, R; Calado, Ricardo; Caetano, Miguel; Rosa, RuiIncreasing anthropogenic pressures in estuaries are responsible for the rise of contaminants in several compartments of these ecosystems. Species that benefit from the nursery services provided by estuaries are exposed to such contaminants (e.g. metals and metalloids). It is therefore relevant to understand if marine invertebrates that use these areas as spawning grounds accumulate contaminants in their tissues throughout embryogenesis. This study aimed to quantify As, Co, Cr, Cu, Mn, Ni, Se, Pb, V and Zn concentrations in both capsule and embryos of the common cuttlefish (Sepia officinalis) in Sado Estuary (Portugal). Moreover, embryos at their initial, intermediate and final stage of development were collected in sites subjected to different anthropogenic pressures. In general, the capsule accumulated higher element concentration throughout embryogenesis which indicates that the capsule acts as an effective barrier against contaminants uptake by the embryo. Although the capsule becomes thinner throughout embryogenesis, embryo's protection does not seem to be compromised at later development stages. Additionally, the higher concentrations of As, Cu, Se and Zn in the embryo in comparison to the capsule suggests important biological roles during the embryogenesis of this cephalopod mollusc.
- Deep-sea seven-arm octopus hijacks jellyfish in shallow watersPublication . Rosa, Rui; Kelly, Jesse T.; Lopes, Vanessa M.; Paula, José Ricardo; Gonçalves, João; Calado, Ricardo; Norman, Mark D.; Barreiros, João P.Pelagic octopods have secondarily left the seafloor and evolved a holopelagic existence. One of the most striking adaptations among a suite of related pelagic octopod families (superfamily Argonautoidea) is their associations with gelatinous zooplankton (jellyfishes and salps). Here, we report a unique interaction between a male octopod (Haliphron atlanticus) and a jellyfish (Pelagia noctiluca) at the sea surface. The oral-to-oral surface orientation of this encounter and sizes of the animals seem not to fit the explanations of camouflage, shelter, and/or transportation for the octopod or “weapons stealing” strategies observed to date in other pelagic octopods. While maneuvering the jelly, H. atlanticus appears to use the jelly’s marginal nematocystic tentacles for protection. This constitutes further evidence that all four octopod families of the Argonautoidea display various interactions with gelatinous zooplankton.
- Deficit in digestive capabilities of bamboo shark early stages under climate changePublication . Rosa, Rui; Pimentel, Marta; Galan, Juan; Baptista, Miguel; Lopes, Vanessa M.; Couto, Ana; Guerreiro, Miguel; Sampaio, Eduardo; Castro, Joana; Santos, Catarina; Calado, Ricardo; Repolho, TiagoLittle empirical information is currently available on the potential effects of acidification and/or warming in sharks, but none exist about digestive capabilities under such future conditions. Here, we investigated the impact of both acidification (ΔpH = 0.5) and warming (+4; 30 °C) on the digestive enzyme levels of recently hatched tropical bamboo shark (Chiloscyllium punctatum). Thirty days post-hatching, juvenile sharks revealed a significant increase in pancreatic trypsin levels under warming, but also a significant decrease under acidification, namely a 42 % drop under present-day temperature and 44 % drop under the warming condition. A similar trend was recorded for the alkaline phosphatase activity in shark’s intestine, i.e. the impact of environmental hypercapnia was also quite notorious—a 50 % drop under present-day temperature and 49 % drop under the warming condition. Thus, our present findings suggest that acidification and warming acted antagonistically, leading to similar enzyme activities under present and future conditions. Future directions on this topic of research should point towards the study of other types of sharks, namely pelagic ones with quite higher energetic demands.
- Development of a Standardized Modular System for Experimental Coral CulturePublication . Rocha, Rui J. M.; Bontas, Bogdan; Cartaxana, Paulo; Leal, Miguel C.; Ferreira, José M.; Rosa, Rui; Serôdio, João; Calado, RicardoThe increasing interest in coral culture for reef restoration, biotechnological applications, and to supply the marine aquarium trade has prompted researchers to optimize coral culture protocols, with emphasis on ex situ production. However, the diversity of experimental systems employed to investigate ex situ coral production may be a bottleneck to the advance of the state of the art, as it impairs reliable comparisons between experiments, as well as the replication and optimization of culture protocols. This study presents a versatile modular culture system for experimental coral production ex situ, assembled using materials and equipments available from suppliers all over the world and thus allowing researchers worldwide to truly replicate experimental setups. The validation of the modular culture system was performed using the soft coral, Sarcophyton cf. glaucum, as a model organism. The validation experiment tested the effect of different light spectra on the photosynthetic performance, symbiont density, chlorophyll and carotenoid pigments concentration, survival, and growth of coral fragments. The validation experiment confirmed the potential of this modular culture system, which ultimately enables researchers to perform direct comparisons among experiments, and more efficiently contribute to advance ex situ coral aquaculture.
- Distinct Bleaching Resilience of Photosynthetic Plastid-Bearing Mollusks Under Thermal Stress and High CO2 ConditionsPublication . Dionísio, Gisela; Faleiro, Filipa; Bispo, Regina; Lopes, Ana Rita; Cruz, Sónia; Paula, José Ricardo; Repolho, Tiago; Calado, Ricardo; Rosa, RuiThe impact of temperature on photo-symbiotic relationships has been highly studied in the tropical reef-forming corals but overlooked in less charismatic groups such as solar-powered sacoglossan sea slugs. These organisms display one of the most puzzling symbiotic features observed in the animal kingdom, i.e., their mollusk-plastid association, which enables them to retain photosynthetic active chloroplasts (i.e., kleptoplasts) retrieved from their algae feed sources. Here we analyze the impact of thermal stress (+4°C) and high pCO2 conditions (ΔpH = 0.4) in survival, photophysiology (i.e., bleaching, photosynthetic efficiency, and metabolism) and stress defense mechanisms (i.e., heat shock and antioxidant response) of solar-powered sacoglossan sea slugs, from tropical (Elysia crispata) and temperate (E. viridis) environments. High temperature was the main factor affecting the survival of both species, while pH only affected the survival of the temperate model. The photobiology of E. viridis remained stable under the combined scenario, while photoinhibition was observed for E. crispata under high temperature and high pCO2. In fact, bleaching was observed within all tropical specimens exposed to warming (but not in the temperate ones), which constitutes the first report where the incidence of bleaching in tropical animals hosting photosynthetic symbionts, other than corals, occurs. Yet, the expulsion of kleptoplasts by the tropical sea slug, allied with metabolic depression, constituted a physiological response that did not imply signs of vulnerability (i.e., mortality) in the host itself. Although the temperate species revealed greater heat shock and antioxidant enzyme response to environmental stress, we argue that the tropical (stenotherm) sea slug species may display a greater scope for acclimatization than the temperate (eurytherm) sea slug. E. crispata may exhibit increased capacity for phenotypic plasticity by increasing fitness in a much narrower thermal niche (minimizing maintenance costs), which ultimately may allow to face severe environmental conditions more effectively than its temperate generalist counterpart (E. viridis).
- Effect of Maternal Size, Reproductive Season and Interannual Variability in Offspring Provisioning of Carcinus maenas in a Coastal LagoonPublication . Rey, Felisa; Domingues, M. Rosário M.; Domingues, Pedro; Rosa, Rui; Orgaz, María D. M.; Queiroga, Henrique; Calado, RicardoMaternal effects and larval experience are considered the most important sources of variability in offspring phenotypes in marine invertebrates. Maternal provisioning during oogenesis is the first of a series of processes that will ultimately affect offspring phenotype and population dynamics. The keystone species of several European estuarine environments, Carcinus maenas, was used as a model to analyse the effect of female size and reproductive season on the fatty acid (FA) profile of newly extruded (stage 1) and ready-to-hatch (stage 3) embryos, as proxies for maternal investment and quality of newly hatched larvae, respectively. A total of 60 ovigerous females of two different sizes (carapace width [CW]: small CW <40 mm; large CW ≥40 mm) from Ria de Aveiro (Portugal) were sampled during three different reproductive periods: early reproductive season (ERS, late March/early April) 2012, ERS-2013 and late reproductive season (LRS; July) 2013. Maternal size was not a reliable indicator of maternal provision or larval quality at hatching. The interannual comparison (ERS-2012 vs. ERS-2013) revealed that the FA profile of stage 3 embryos was likely shaped by environmental conditions in the coastal lagoon during incubation. The seasonal comparison (ERS-2013 vs. LRS-2013) showed that embryos in the LRS had higher quality lipid content than embryos in the ERS, suggesting an increase of energetic reserves destined for reproduction in females in the LRS. Studies on maternal investment that overlook temporal variability should be interpreted with caution, especially in species inhabiting highly dynamic environments such as coastal lagoons and estuaries.
- Effects of elevated temperature and CO2 on intertidal microphytobenthosPublication . Cartaxana, Paulo; Vieira, Sónia; Ribeiro, Lourenço; Rocha, Rui JM; Cruz, Sónia; Calado, Ricardo; da Silva, Jorge MarquesBackground: Microphytobenthos (MPB) are the main primary producers of many intertidal and shallow subtidal environments. Although these coastal ecosystems are particularly vulnerable to anthropogenic activities, little is known on the effects of climate change variables on the structure and productivity of MPB communities. In this study, the effects of elevated temperature and CO2 on intertidal MPB biomass, species composition and photosynthetic performance were studied using a flow-through experimental life support system. Results: Elevated temperature had a detrimental effect on MPB biomass and photosynthetic performance under both control and elevated CO2. Furthermore, elevated temperature led to an increase of cyanobacteria and a change in the relative abundance of major benthic diatom species present in the MPB community. The most abundant motile epipelic species Navicula spartinetensis and Gyrosigma acuminatum were in part replaced by tychoplanktonic species (Minidiscus chilensis and Thalassiosira cf. pseudonana) and the motile epipelic Nitzschia cf. aequorea and N. cf. aurariae. Elevated CO2 had a beneficial effect on MPB biomass, but only at the lower temperature. It is possible that elevated CO2 alleviated local depletion of dissolved inorganic carbon resulting from high cell abundance at the sediment photic layer. No significant effect of elevated CO2 was detected on the relative abundance of major groups of microalgae and benthic diatom species. Conclusions: The interactive effects of elevated temperature and CO2 may have an overall detrimental impact on the structure and productivity of intertidal MPB, and eventually in related ecosystem services.
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