Papers by Catarina Vinagre
Marine Biology, 2017
Trait-based differences among individuals are
common and particularly important for polymorphic s... more Trait-based differences among individuals are
common and particularly important for polymorphic species
in which alternative morphs exploit the same habitat
types but occupy different trophic niches. The shrimp
Hippolyte obliquimanus inhabits shallow-water vegetated
habitats, particularly the seasonal and physically complex
brown alga Sargassum furcatum and the less-structured but
temporally stable red weed Galaxaura marginata. Two main
colour morphs can be found in these habitats: homogeneous
colour-changing shrimp that are able to match to their
background and show little mobility, and transparent shrimp
with coloured stripes, which cannot match their background,
show lower habitat fidelity and are more evenly distributed
between algal habitats. We used carbon and nitrogen stable
isotopes and Bayesian mixing models to test whether morphspecific
patterns of habitat use observed for H. obliquimanus
living in Sargassum and Galaxaura meadows also influence trophic niche segregation. We observed morph-specific
trophic differences that varied with habitat, with narrower
niche space and lower niche overlap between morphs in
Galaxaura meadows, and broader niche space and higher
niche overlap between morphs in Sargassum habitat. Niche
segregation between morphs occurred only in Galaxaura,
where available resources are presumably less abundant
than in Sargassum and the strength of competition between
morphs is higher. Resource availability and habitat stability
are likely driving dietary niche segregation between shrimp
morphs, which can ultimately affect population dynamics
and community composition in a spatially heterogeneous
and seasonal habitat.
Mortality of fish has been reported in tide pools during warm days. That means that tide pools ar... more Mortality of fish has been reported in tide pools during warm days. That means that tide pools are potential ecological traps for coastal organisms, which happen when environmental changes cause maladaptive habitat selection. Heatwaves are predicted to increase in intensity, duration and frequency, making it relevant to investigate the role of tide pools as traps for coastal organisms. However, heat waves can also lead to acclimatization. If organisms undergo acclimatization prior to being trapped in tide pools, their survival chances may increase. Common tide pool species (46 species in total) were collected at a tropical and a temperate area and their upper thermal limits estimated. They were maintained for 10 days at their mean summer sea surface temperature +3˚C, mimicking a heatwave. Their upper thermal limits were estimated again, after this acclimation period, to calculate each species' acclimation response. The upper thermal limits of the organisms were compared to the temperatures attained by tide pool waters to investigate if 1) tide pools could be considered ecological traps and 2) if the increase in upper thermal limits elicited by the acclimation period could make the organisms less vulnerable to this threat. Tropical tide pools were found to be ecological traps for an important number of common coastal species, given that they can attain temperatures higher than the upper thermal limits of most of those species. Tide pools are not ecological traps in temperate zones. Tropical species have higher thermal limits than temperate species, but lower acclimation response, that does not allow them to survive the maximum habitat temperature of tropical tide pools. This way, tropical coastal organisms seem to be, not only more vulnerable to climate warming per se, but also to an increase in the ecological trap effect of tide pools.
The rapid expansion of the invasive coral, Tubastraea spp., along the coast of Brazil is consider... more The rapid expansion of the invasive coral, Tubastraea spp., along the coast of Brazil is considered a serious problem with major ecological and socioeconomic impacts. However, studies on the structure and dynamics of the food web associated to this coral, are still missing. At the basis of this coral another non-indigenous species is very often found, the mytilid Leiosolenus aristatus, a borer bivalve that perforates the calcareous base of Tubastraea spp. and seems to be profiting from the invasive nature of its coral host. Stable isotopic analysis was applied to the main macro-organisms occurring amidst Tubastraea spp. colonies, to 1) provide the first trophic characterization of the food web associated with Tubastraea spp., and to 2) elucidate if L. aristatus has a trophic link to its coral host Tubastraea spp. The food web that accompanies this invasive coral seems to be mostly composed of suspension feeders. It was also concluded that both Tubastraea spp. and L. aristatus are both suspension feeders consuming similar resources. This way, L. aristatus seems to profit from the expansion of Tubastraea spp. because the coral provides valuable habitat where food resources are likely abundant. The coral, however, does not directly nourish the boring bivalve. As Tubastraea spp. progresses in its invasion of new areas, L. aristatus should follow. Such interaction appears to constitute an illustration of the invasion meltdown hypothesis , which states that the negative impacts of non-indigenous species will be intensified by their interactions with other invasive species.
Tropical organisms are predicted to be among the most impacted by increasing sea surface temperat... more Tropical organisms are predicted to be among the most impacted by increasing sea surface temperatures, particularly those from intertidal habitats. In this study, a complete thermal biology assessment was conducted for two widespread tropical Atlantic shallow reef fish: Abudefduf saxatilis (damselfish) and Scartella cristata (blenny),
which make extensive use of tide pools. The main objectives were to measure the time-course changes during
one month in i) thermal and oxidative stress biomarkers (in gills, muscle and skin), ii) upper thermal limits,
acclimation capacity and thermal safety margins and iii) body size, condition and energy reserves (total protein
and lipid contents), under two temperature treatments (control – mean summer temperature, and elevated
temperature −+ 3 °C, as projected by climate warming scenarios for the end of this century).
Results from biomarker analyses suggest that under increased temperature, both species displayed a typical
response of physiological stress characterized by the activation of molecular chaperones and antioxidant protection.
Both species presented a significant acclimation potential in the long term, as shown by increased critical
thermal maxima values at higher temperature. However, these species may already be at risk during summer
heat waves, as thermal safety margins for both species were low. Additionally, despite acclimation, some energetic
tradeoffs may exist, since specimens from both species showed smaller body sizes at higher temperature
(even though maintaining body condition). Finally, temperature treatments had a significant influence not only
in the total amount of energy reserves (lipid contents) but also in their rate of deposition or depletion (total
proteins and lipid contents). This is the first multi-end-point holistic approach to assess the impact of warming in shallow tropical water fish and it highlights the high risk that intertidal organisms are facing in both present and future sea surface temperature conditions.
A B S T R A C T Determining the spatial scale is a crucial stage in any ecological study. However... more A B S T R A C T Determining the spatial scale is a crucial stage in any ecological study. However, knowledge on the effect of spatial scale on food web network properties is still lacking in published literature. In this work, the effect of spatial scale on the network properties was determined for the Tagus estuary ecosystem. The food web of the Tagus estuary was assembled at three spatial scales, in terms of grain (resolution) and extent. In terms of grain, the three scales defined were: small grain (30 sites), medium grain (15 sites) and large grain (6 sites). In terms of extent, the three scales defined were: extended estuary (30 sites), strictly estuarine (20 sites), nursery area (6 sites). The lists of species for each site were merged and used to construct one major food web containing all species observed, at each of the spatial scales under analysis. It was concluded that the spatial extent of the sampling highly influenced food web networks properties, more than grain, and should thus be carefully chosen when conducting food web studies in estuaries, as well as in other ecosystems that exhibit strong environmental gradients. Studies that aim to characterize estuarine food webs should encompass the full extent of the salinity gradient.
Knowledge of thermal stress biology for most tropical fish species in reef ecosystems under clima... more Knowledge of thermal stress biology for most tropical fish species in reef ecosystems under climate change is still quite limited. Thus, the objective of this study was to measure the time-course changes of thermal stress bio-markers in the commercially exploited coral reef fish Amphiprion ocellaris, during a laboratory simulated event of increased temperature. Heat shock protein 70 kDa (Hsp70) and total ubiquitin (Ub) were determined in the muscle (lethal method) and in the fin (non-lethal alternative method) under two temperature treatments (control – 26 °C and elevated temperature – 30 °C) throughout one month with weekly samplings. Results suggest that biomarker basal levels are tissue-specific and influence the degree of response under temperature exposure. Responses were highly inducible in the muscle but not in fin tissue, indicating that the latter is not reliable for monitoring purposes. Thermal stress was observed in the muscle after one week of exposure (both biomarkers increased significantly) and Ub levels then decreased, suggesting the animals were able to acclimate by maintaining high levels of Hsp70 and through an effective protein turnover. In addition, the results show that mortality rates did not differ between treatments. This indicates that A. ocellaris is capable of displaying a plastic response to elevated temperature by adjusting the protein quality control system to protect cell functions, without decreasing survival. Thus, this coral reef fish species presents a significant acclimation potential under ocean warming scenarios of +4 °C. Monitoring of thermal stress through a non-lethal method, fin-clipping, although desirable proved to be inadequate for this species.
Estuarine Coastal and Shelf Science, 2008
In estuarine sediment flats benthic macroinvertebrates are intensively consumed by a variety of p... more In estuarine sediment flats benthic macroinvertebrates are intensively consumed by a variety of predators, such as aquatic birds and nekton (mostly fish and crustaceans). However, there is still a lack of conclusive studies that evaluate if this predation has a relevant impact on the populations of those invertebrates, which are a key element of the estuarine food chain. In the Tagus estuary we experimentally tested and quantified the impact of predation on the polychaete Hediste diversicolor, one of the most important prey for a variety of predators in many estuaries. Using an exclusion experiment, we compared the seasonal variation in the densities of H. diversicolor from February to November in sediment plots (1) available to both bird and nekton predators, (2) just to nekton, and (3) without predators. We also followed changes in the abundance of potential predators throughout the study. The lowest densities were systematically observed in the plots accessible to all predators, followed by those which excluded just birds, and finally by those that excluded all predators. The exclosures were in place for 9 months, at the end of which the average density of H. diversicolor in the plots protected from all predators was eight times greater than in those without any protection. These results demonstrate that predation had a major impact on the densities of H. diversicolor. The relative importance of bird and nekton predation varied along the study, and this seems to be determined by different peaks of abundance of the two types of predators. However, when present in high densities, birds and nekton seem to have a similar impact on H. diversicolor. Our results suggest that predation is a key factor on the population dynamics of H. diversicolor. In addition, the levels of predation that we observed suggest that this polychaete can be a limited resource, and this could have major ecological consequences for predators for which it is a key prey.
The effects of increased temperature were tested in Amphiprion ocellaris, using a cellular diagno... more The effects of increased temperature were tested in Amphiprion ocellaris, using a cellular diagnostics approach (in several tissues) combined with an organismal approach (body condition). Clownfish were exposed to a one month experiment following two temperature treatments: control (26 • C) and elevated temperature (30 • C). Fish were sampled at 0, 7, 14, 21 and 28 days for (1) assessment of stress biomark-ers (catalase, lipid peroxidation, glutathione-S-transferase, superoxide dismutase, acetylcholinesterase, heat shock protein 70 kDa and ubiquitin – in brain, gills, liver, intestine and muscle), (2) estimation of integrated biomarker response index based on the biomarkers tested and (3) assessment of Fulton's K index. Results show all biomarkers except acetylcholinesterase responded consistently and significantly to elevated temperature across tissue types suggesting they are suitable indicators of thermal stress in A. ocellaris. Biomarker levels were tissue-specific, and in addition, the most reactive tissues to temperature were muscle, gills and liver which suggest that highly oxygenated tissues seem to be the most responsive under thermal stress. The most responsive sampling times to increased temperature were T7 and T28: thermal stress was observed after 7 days of exposure (biomarker levels increased), then a pattern of decrease in biomarker levels towards the end of the experiment was observed, which may suggest fish were able to acclimate to exposure conditions. This indicates that A. ocellaris probably lives far from its upper thermal limit and is capable of adjusting the protein quality control system and enzymes' activities to protect cell functions under elevated temperatures. The temperature treatment did not significantly influence body condition of the animals but biomarkers were negatively correlated to wet body weight. This suggests that thermal acclimation incurs at some energetic cost. In conclusion, these results suggest that this coral reef fish species presents a significant acclimation potential under ocean warming scenarios of +4 • C.
Stable isotope analysis has been applied to the investigation of movement in several species, inc... more Stable isotope analysis has been applied to the investigation of movement in several species, including marine animals. However, its application to nekton living in open coastal areas is still very scarce. This study aims to test if stable isotope analysis can be used for this purpose over a much wider spatial scale than previously investigated. Stable isotope analysis was used to 1) investigate isotopic variation in shrimp and fish, in 11 sites, along a 160 km coastal stretch, to 2) determine the site fidelity of the individuals within each species, and to 3) test the relation between the body size of the individuals within each species, at each site and the percentage of isotopic deviants. Site fidelity was the highest for the intertidal fish Gobius paganellus and Coryphoblennius galerita, with 60% and 64% of individuals considered residents, respectively, and lowest for the demersal fish Diplodus vulgaris and Diplodus sargus with 23% and 33% of resident individuals, respectively. The percentage of isotopic deviants was not correlated with length in any species. Site fidelity was considerably higher than that previously found for other open coastal areas and similar to more structured environments, like coastal ponds. It was hypothesized that the complex tri-dimensional structure of the rocky reefs that occur in this area, often encompassing channels and tide pools, offers conditions favourable to high site fidelity. This study shows that stable isotopes can be used to infer nekton movement in wide open coastal areas.
– The Portuguese coast is particularly adequate for studies on the impact of climate change on fi... more – The Portuguese coast is particularly adequate for studies on the impact of climate change on fisheries, as it has faced an increase in both air and sea surface temperature and a decrease in intensity and frequency of rainfall. Ecological responses to climate change have already been observed in Portuguese waters, with consequences in fisheries. Regional climate models have predicted a further decrease in rainfall in Portugal by the end of the century, which will have a strong impact on the runoff into coastal areas. River drainage affects the physical, chemical and biological properties of coastal ecosystems, regulating habitat availability and favouring their productivity. The present study analysed the influence of river drainage on landings of coastal ports in the vicinity of four hydrologically distinct estuaries. Unlike previous results obtained for the Mediterranean, no significant relationships between river drainage and landings were found. Relationships between drainage and landings can be inconsistent among regions and dependent on how strongly a food web relies on nutrients and organic matter of river origin. In the Portuguese coast, an upwelling regime is of particular importance for the richness and diversity of the coastal ecosystem and for fisheries. The complexity of the coastal upwelling phenomenon together with a possible interaction of several other smaller scale factors acting on recruitment of commercial species may mask the effects of river drainage on landings. Nevertheless, as accentuated decreases in rainfall have been predicted for Portugal, the resulting reduction in river drainage may still strongly impact fisheries in the future.
Fish were sampled monthly in four tidal pools, for two years, on the west Portuguese coast. Speci... more Fish were sampled monthly in four tidal pools, for two years, on the west Portuguese coast. Species diversity of transient fish was higher than that found in previous studies, in other parts of the world. The transient fish population comprised six species: the white seabream, Diplodus sargus, sand smelt, Atherina spp., the thinlip grey mullet, Liza ramada, the Baillon's wrasse, Symphodus bailloni, the zebra seabream, Diplodus cervinus and the European pilchard, Sardina pilchardus. Abundance varied seasonally, yearly, and among pools, with peak numbers in spring and summer. The most abundant species in all pools, both as larvae and juveniles, was D. sargus. Diplodus sargus and Atherina spp. were present in most pools, from spring to autumn, while rare species were present mostly in the spring-summer period. Smaller mean sizes of larvae and juveniles were observed at the beginning of spring of 2011 (March-April) and at the end of spring/beginning of summer of 2012 (May-June). Mean size of larvae and juveniles often showed a continuous increase from spring to autumn in both years. The highest density peaks were due to the high number of post-larvae entering the pools in spring. In most pools, the overall condition (Fulton's K ) of D. sargus increased throughout the year, in both years. The species richness, the high densities of early stages, and their continuous growth observed in tidal pools strongly emphasize the importance of these environments for larvae and juveniles of several transient marine fishes.
Climate change has pervasive effects on marine ecosystems, altering biodiversity patterns, abunda... more Climate change has pervasive effects on marine ecosystems, altering biodiversity patterns, abundance and distribution of species, biological interactions, phenology, and organisms' physiology, performance and fitness. Fish early life stages have narrow thermal windows and are thus more vulnerable to further changes in water temperature. The aim of this study was to address the sensitivity and underlying molecular changes of larvae of a key fisheries species, the sea bream Sparus aurata, towards ocean warming. Larvae were exposed to three temperatures: 18 °C (control), 24 °C (warm) and 30 °C (heat wave) for seven days. At the end of the assay, i) survival curves were plotted for each temperature treatment and ii) entire larvae were collected for proteomic analysis via 2D gel electrophoresis, image analysis and mass spectrometry. Survival decreased with increasing temperature, with no larvae surviving at 30 °C. Therefore, proteomic analysis was only carried out for 18 °C and 24 °C. Larvae up-regulated protein folding and degradation, cytoskeletal reorganization , transcriptional regulation and the growth hormone while mostly down-regulating cargo transporting and porphyrin metabolism upon exposure to heat stress. No changes were detected in proteins related to energetic metabolism suggesting that larval fish may not have the energetic plasticity needed to sustain cellular protection in the long-term. These results indicate that despite proteome modulation, S. aurata larvae do not seem able to fully acclimate to higher temperatures as shown by the low survival rates. Consequently, elevated temperatures seem to have bottleneck effects during fish early life stages, and future ocean warming can potentially compromise recruitment's success of key fisheries species.
The use of tidal pools during early ontogeny is likely to enhance growth, condition and survival ... more The use of tidal pools during early ontogeny is likely to enhance growth, condition and survival chances of the transient marine fish larvae and juveniles that use them. However , the diet of such individuals within tidal pools is poorly known; this knowledge is important to understand why such high numbers of individuals use these environments in spring and summer on the Portuguese coast. Transient marine fishes were sampled monthly over a two-year period in four tidal pools of a rocky reef on the west Portuguese coast. The diet composition in the tidal pools of the most abundant marine fish larvae/juveniles, Diplodus sargus and Atherina spp., were investigated. Stomach and gut contents of 483 individuals (354 D. sargus ranging in total length from 9 to 87 mm and 134 Atherina spp. ranging in total length from 10 to 31 mm) were analyzed and dietary indices estimated for the different developmental stages. The diet of D. sargus composed mainly harpacticoid copepods, chironomid larvae, ostracods, chiron-omid adults and amphipods; whereas the diet of Atherina spp. was mainly harpacticoid copepods, ostracods and gas-tropods. Along the ontogenetic development, the proportions and diversity of food items in the D. sargus diet varied. Importance of the harpacticoid copepods decreased with increasing fish size, while that of amphipods and isopods increased. Larvae and juvenile D. sargus and Atherina spp. found in rocky reef tidal pools are opportunistic consumers of a wide range of prey and thus take advantage of the high prey availability in these habitats.
Rocky shores are among the most-intensively studied ecosystems, however, tidal pools remain relat... more Rocky shores are among the most-intensively studied ecosystems, however, tidal pools remain relatively under-studied. This study aims to investigate the habitat use and dynamics of the shrimp species that occur in tidal pools of a Northeastern Atlantic coast, the Portuguese coast, in particular species composition, abundance, seasonality and size structure. Shrimps were sampled monthly from six tidal pools for one year, in the west Portuguese coast. Species diversity was much higher than that found in previous studies, in other parts of the world. The shrimp population comprised 8 species: the European rock shrimp, Palaemon elegans, the common prawn, Palaemon serratus, the Atlantic ditch shrimp, Palaemon varians, the Baltic prawn, Palaemon adspersus, the Oriental shrimp, Palaemon macrodactylus and the relatively rare shrimps Eualus sollaudi, Eualus drachi and Caridion gordoni. Shrimp populations varied seasonally and among pools, with peak numbers in spring and summer. The most abundant species was P. elegans. P. elegans was present in all pools, throughout most of the year. Rare and exotic species were present mostly in spring-summer. Lower mean sizes of all shrimp were registered in the beginning of spring, most often in April or May, and gradually increased until winter. New-recruits of the most abundant species, P. elegans, generally entered the pools in spring and formed a high proportion of the population between April and August. They were responsible for the highest abundance peaks of shrimps occurring in the pools. The species richness and high numbers of juveniles occurring in tidal pools suggest that these environments may be nursery areas for coastal shrimp.
Current concerns about climate change emphasize the need for an accurate monitoring of physiologi... more Current concerns about climate change emphasize the need for an accurate monitoring of physiological conditions in wild populations. Therefore, the aims of this work were to a) assess the response of the octocoral Veretillum cynomorium to thermal variation in natural populations during low tide, by quantifying several biochemical indicators of thermal and oxidative stress and b) evaluate the effect of seasonality in the results and the adequacy of the use of biochemical indicators of stress in field monitoring studies in octocorals. Sampling took place during spring (April) and summer (June). Heat shock protein (Hsp70) and ubiquitin (Ub) content, enzyme activities — superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), and lipid perox-idation (LPO) were assessed in rachis and peduncle tissues separately. The results showed significant seasonal fluctuations in the set of biomarkers tested. Differences were detected between spring and summer, with significant decreases in biomarker levels from April to June being a major observed trend. These results suggest that V. cynomorium is thermo-tolerant during summer low tide conditions. Seasonal variation seems to reflect a metabolic suppression strategy and/or may also be related to seasonal changes in food availability and reproductive status. Differences in activity between tissue types were also found significant for GST, LPO and Ub. Biomarker levels were correlated with total protein concentration, but not with wet body weight of the specimens. This study suggests that season influences the expression of biomarkers and must be taken into consideration in the preliminary stages of sampling design for climate change biomonitoring studies. In addition, the results suggest that this octocoral species is likely to survive in future challenging thermal conditions.
The characterization of food web structure, energy pathways and trophic linkages is essential for... more The characterization of food web structure, energy pathways and trophic linkages is essential for the understanding of ecosystem functioning. Isotopic analysis was performed on food web components of the rocky intertidal ecosystem in four sites along the Portuguese west coast. The aim was to 1) determine the general food web structure, 2) estimate the trophic level of the dominant organisms and 3) track the incorporation of organic carbon of different origins in the diet of the top consumers. In this food web, fish are top consumers, followed by shrimp. Anemones and gastropods are intermediate consumers, while bivalves and zooplankton are primary consumers. Macroalgae Bifurcaria bifurcata, Ulva lactuca, Fucus vesiculosus, Codium sp. and phytoplankton are the dominant producers. Two energy pathways were identified, pelagic and benthic. Reliance on the benthic energy pathway was high for many of the consumers but not as high as previously observed in subtidal coastal food webs. The maximum TL was 3.3, which is indicative of a relatively short food web. It is argued that the diet of top consumers relies directly on low levels of the food web to a considerable extent, instead of on intermediate levels, which shortens the trophic length of the food web.
Ecological forecasting on the likely impacts of climate warming is crucial at a time when several... more Ecological forecasting on the likely impacts of climate warming is crucial at a time when several ecosystems seem to be responding to this environmental threat. Among the most important questions are: which are the most vulnerable organisms to climate warming and where are they? Recently, there has been debate on whether the tropics or temperate zones are more vulnerable to warming. Vulnerability toward higher temperatures will depend on the organisms' thermal limits and also on their acclimation capacity, which remains largely unknown for most species. The aim of the present work was to estimate (1) the upper thermal limits (Critical Thermal Maximum (CTMax)), (2) the warming tolerance (CTMax – Maximum Habitat Temperature) and (3) the acclimation capacity of tropical and temperate rocky shore organisms. Differences in biological groups (decapod crustaceans vs fish) were investigated and the effect of region (tropical vs temperate) and habitat (intertidal vs subtidal) was tested. Overall, 35 species were tested. For the assessment of the acclimation capacity, tropical-temperate pairs of closely related species of shrimp, crab and fish were selected. Warming tolerance was higher for temperate species than for tropical species and higher for subtidal species than for intertidal species, confirming that species with the highest thermal limits have the lowest warming tolerance. All species tested presented some accli-mation capacity (CTMax Trial − CTMax Control), with the exception of gobiid fish, which was not observed to acclimate. The tropical species tested showed a lower acclimation capacity than their temperate counterparts. Given that tropical rocky shore organisms are already living very close to their thermal limits and that their acclimation capacity is limited, it is likely that the impacts of global warming will be evident sooner in the tropics than in the temperate zone.
Chitons are very common molluscs on European rocky shores. They are common prey of fish and crabs... more Chitons are very common molluscs on European rocky shores. They are common prey of fish and crabs and often display several colour morphs within a given habitat. Predation is one of the potential mechanisms accounting for chiton colour polymorphism. The colour variation is considered to provide a camouflage protection through a match with the substratum surface typology. However, the effectiveness of chiton polymorphism as a predation defence requires further investigation. Previously we found a relationship between chiton colour morphs and substrate characteristics, with chitons most commonly found on substrates that were of similar colour to their shells. Here, we examined whether each morph displayed an active choice for matching the substratum. Next, we assessed if the predation success of the intertidal common crab Carcinus maenas varied significantly with the absence/presence of an apparent camouflage effect created between the chiton colour morph and the substratum type. The present study indicates that chiton colour morphs probably actively choose substratum types where they blend in. Carcinus maenas was able to prey on all Lepidochitona cinereus colour morphs, regardless of the substrate camouflage effect. Surprisingly, the predation frequency was higher on camouflaged chitons than on contrasting chitons. It was concluded that chiton camouflage is probably not a defence mechanism against predation by the crab C. maenas, and that chiton colour polymorphism is probably promoted by other, more visual predators.
Climate change is disturbing marine biological processes, and impacting goods and services provid... more Climate change is disturbing marine biological processes, and impacting goods and services provided to society. Physiological studies are a major contributor to the improvement of biological forecasting in the context of climate change. Oxidative stress biomarkers are useful tools to assess the metabolic status and health of organisms, improving management of wild and cultured populations. The aims of this study were to assess the health status and vulnerability of Sparus aurata juveniles toward ocean warming and heat wave events by (1) exposing fish to a thermal ramp from 18 • C until their Critical Thermal Maximum (≈35 • C) and (2) quantifying oxidative stress biomarkers in several organs, i.e. lipid peroxidation (LPO), catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), and cytochrome CYP1A. Fish showed signs of oxidative stress in every tissue tested (gills, muscle, liver, brain and intestine), the most affected being muscle and liver, which showed greater increases in LPO. In general , antioxidant enzymes increased their activity: CAT increased in every organ tested, GST increased in every organ except brain (no change) and SOD increased in every organ except intestine (no change) and brain (decrease, probably due to enzyme denaturation). Muscle showed the greatest stress response with a massive increase in GST. Hepatic CYP1A decreased upon warming suggesting that temperature influences detoxifying mechanisms and may affect fish health. These results are significant in the context of climate change and associated impacts on fisheries and aquaculture because over-induction of oxidative stress due to warming can induce health problems, mortality and shortened lifespan.
(Ca 2+ , Na + , K +) in the muscle of shrimps under spring and summer conditions in the wild. Tis... more (Ca 2+ , Na + , K +) in the muscle of shrimps under spring and summer conditions in the wild. Tissue-specific bio-marker responses were detected, with greater induction in the muscle (increased Tub, CAT, SOD and LPO). Vis-ceral mass showed decreased (Tub, CAT, GST) or constant (Hsp70, SOD) biomarker levels except for LPO, which increased in summer-acclimatized animals. Potassium ion increased in the muscle of summer-acclimatized shrimps suggesting ionic regulation. This study showed that P. elegans employs different biochemical strategies depending on the season, potentially as a mechanism of seasonal acclimatization involving the protein quality control system, oxidative stress pathways and ionic regulation. These effects should be considered in environmental monitoring programs to avoid the interference of confounding variables, which change seasonally. Abstract Temperate species undergo wide variations of abiotic factors according to season, with temperature and photoperiod being two of the main factors that change. Given that several laboratory studies have reported the capacity of intertidal species to trigger the cellular stress response when exposed to challenging environmental conditions, the aim of this study was to address this capacity in situ (38°42′N, 9°29′W) in a key intertidal species, the shrimp Palaemon elegans. This study assessed changes in (1) thermal stress (heat-shock protein 70 kDa—Hsp70, total ubiquitin—Tub) and oxidative stress biomarkers (antioxidant enzymes: catalase—CAT, superoxide dismutase—SOD, glu-tathione-S-transferase—GST, and oxidation products: lipid peroxidation—LPO) in the muscle and visceral mass, and assessed changes in (2) ion concentrations
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Papers by Catarina Vinagre
common and particularly important for polymorphic species
in which alternative morphs exploit the same habitat
types but occupy different trophic niches. The shrimp
Hippolyte obliquimanus inhabits shallow-water vegetated
habitats, particularly the seasonal and physically complex
brown alga Sargassum furcatum and the less-structured but
temporally stable red weed Galaxaura marginata. Two main
colour morphs can be found in these habitats: homogeneous
colour-changing shrimp that are able to match to their
background and show little mobility, and transparent shrimp
with coloured stripes, which cannot match their background,
show lower habitat fidelity and are more evenly distributed
between algal habitats. We used carbon and nitrogen stable
isotopes and Bayesian mixing models to test whether morphspecific
patterns of habitat use observed for H. obliquimanus
living in Sargassum and Galaxaura meadows also influence trophic niche segregation. We observed morph-specific
trophic differences that varied with habitat, with narrower
niche space and lower niche overlap between morphs in
Galaxaura meadows, and broader niche space and higher
niche overlap between morphs in Sargassum habitat. Niche
segregation between morphs occurred only in Galaxaura,
where available resources are presumably less abundant
than in Sargassum and the strength of competition between
morphs is higher. Resource availability and habitat stability
are likely driving dietary niche segregation between shrimp
morphs, which can ultimately affect population dynamics
and community composition in a spatially heterogeneous
and seasonal habitat.
which make extensive use of tide pools. The main objectives were to measure the time-course changes during
one month in i) thermal and oxidative stress biomarkers (in gills, muscle and skin), ii) upper thermal limits,
acclimation capacity and thermal safety margins and iii) body size, condition and energy reserves (total protein
and lipid contents), under two temperature treatments (control – mean summer temperature, and elevated
temperature −+ 3 °C, as projected by climate warming scenarios for the end of this century).
Results from biomarker analyses suggest that under increased temperature, both species displayed a typical
response of physiological stress characterized by the activation of molecular chaperones and antioxidant protection.
Both species presented a significant acclimation potential in the long term, as shown by increased critical
thermal maxima values at higher temperature. However, these species may already be at risk during summer
heat waves, as thermal safety margins for both species were low. Additionally, despite acclimation, some energetic
tradeoffs may exist, since specimens from both species showed smaller body sizes at higher temperature
(even though maintaining body condition). Finally, temperature treatments had a significant influence not only
in the total amount of energy reserves (lipid contents) but also in their rate of deposition or depletion (total
proteins and lipid contents). This is the first multi-end-point holistic approach to assess the impact of warming in shallow tropical water fish and it highlights the high risk that intertidal organisms are facing in both present and future sea surface temperature conditions.
common and particularly important for polymorphic species
in which alternative morphs exploit the same habitat
types but occupy different trophic niches. The shrimp
Hippolyte obliquimanus inhabits shallow-water vegetated
habitats, particularly the seasonal and physically complex
brown alga Sargassum furcatum and the less-structured but
temporally stable red weed Galaxaura marginata. Two main
colour morphs can be found in these habitats: homogeneous
colour-changing shrimp that are able to match to their
background and show little mobility, and transparent shrimp
with coloured stripes, which cannot match their background,
show lower habitat fidelity and are more evenly distributed
between algal habitats. We used carbon and nitrogen stable
isotopes and Bayesian mixing models to test whether morphspecific
patterns of habitat use observed for H. obliquimanus
living in Sargassum and Galaxaura meadows also influence trophic niche segregation. We observed morph-specific
trophic differences that varied with habitat, with narrower
niche space and lower niche overlap between morphs in
Galaxaura meadows, and broader niche space and higher
niche overlap between morphs in Sargassum habitat. Niche
segregation between morphs occurred only in Galaxaura,
where available resources are presumably less abundant
than in Sargassum and the strength of competition between
morphs is higher. Resource availability and habitat stability
are likely driving dietary niche segregation between shrimp
morphs, which can ultimately affect population dynamics
and community composition in a spatially heterogeneous
and seasonal habitat.
which make extensive use of tide pools. The main objectives were to measure the time-course changes during
one month in i) thermal and oxidative stress biomarkers (in gills, muscle and skin), ii) upper thermal limits,
acclimation capacity and thermal safety margins and iii) body size, condition and energy reserves (total protein
and lipid contents), under two temperature treatments (control – mean summer temperature, and elevated
temperature −+ 3 °C, as projected by climate warming scenarios for the end of this century).
Results from biomarker analyses suggest that under increased temperature, both species displayed a typical
response of physiological stress characterized by the activation of molecular chaperones and antioxidant protection.
Both species presented a significant acclimation potential in the long term, as shown by increased critical
thermal maxima values at higher temperature. However, these species may already be at risk during summer
heat waves, as thermal safety margins for both species were low. Additionally, despite acclimation, some energetic
tradeoffs may exist, since specimens from both species showed smaller body sizes at higher temperature
(even though maintaining body condition). Finally, temperature treatments had a significant influence not only
in the total amount of energy reserves (lipid contents) but also in their rate of deposition or depletion (total
proteins and lipid contents). This is the first multi-end-point holistic approach to assess the impact of warming in shallow tropical water fish and it highlights the high risk that intertidal organisms are facing in both present and future sea surface temperature conditions.