Seasonal and spatial variations of fish trophic guilds in a shallow,semi-enclosed tropical estuarine bay

A study on seasonal and spatial variations of feeding habits and trophic guilds of dominant fish species in Pattani Bay during March 2003 to February 2004 was aimed at classifying diet composition, identifying dominant food components of each species, categorizing trophic guilds of the community and evaluating effects of habitat characteristics and seasonality on guild organization. Most fishes showed high food intake, fed on a diverse range of food items but relied heavily on calanoid copepods and shrimps. All species, with the exception of Epinephelus coioides, were classified as specialist feeders. Four main dietary guilds were classified. Three of these were classified as the guilds dominated by at least two major food items. Significant variations in trophic guilds of 28 fish species based on habitat types and seasons were also identified. They could be divided into three seasonal groups and three site-groups and a single site. Trophic organization for each season and habitat ranged from two to four groups. This information identifies groups of fishes that seasonally and spatially utilize different food resources within a semi-enclosed estuarine bay ecosystem.     

Seasonal variations in the biochemical composition and lipoperoxidation of Hyalella curvispina (Crustacea, Amphipoda)

We assessed the effect of seasonal variations on the biochemical composition and lipoperoxidation of an amphipod crustacean, Hyalella curvispina, which inhabits the coastal plain of the state of Rio Grande do Sul, and correlated this with information on the biology of the species. The animals were collected monthly from September 2003 to August 2005, in Gentil Lagoon, Tramandaí, Rio Grande do Sul, Brazil. Glycogen levels, total proteins, total lipids, triglycerides, and lipoperoxidation were measured for each sex separately. The results suggest that these animals have seasonal storage and degradation of the energy substrates investigated. During summer, glycogen, total lipids, and triglycerides were stored, and were utilized especially during autumn and winter. Proteins were utilized differently in males and females. Females stored proteins especially in spring and used them in summer; whereas males stored proteins especially in spring and used them in winter. The levels of lipoperoxidation during the year differed between females and males. These variations may be related to biotic factors (e.g., reproduction period and others) and to abiotic factors (e.g., water temperature, salinity and others).     

Feeding rates of amphipods in boreal lakes: is there a seasonal shift independent of temperature and photoperiod?

In boreal lakes, temperature and photoperiod are important environmental cues affecting reproduction, growth and feeding rates of benthic invertebrates; however, how invertebrates cope with seasonal changes in the availability of their food sources has rarely been addressed. In this study, where temperature and light conditions were controlled, we aimed at assessing whether Hyalella azteca amphipods from the littoral zone of boreal lakes adjust their feeding rates in response to the dynamics of their food sources and their population structure. Using a gravimetric approach, we compared the ingestion and absorption rates of amphipods from a natural population collected periodically during the ice-free season. Amphipods were fed in the laboratory with conditioned leaf detritus. Feeding rates increased regardless of seasonal variations of temperature and photoperiod in the lake. Field data suggest this increase could be linked to seasonal changes in the population structure or in the diet of amphipods. This suggests that H. azteca amphipods adjusted their feeding rates with their energy and nutrient requirements and/or developed a compensatory feeding trade-off to cope with the dynamics of their different food sources in lakes.     

Bio‐energetics underpins the spatial response of North Sea plaice (Pleuronectes platessa L.) and sole (Solea solea L.) to climate change

Climate change is currently one of the main driving forces behind changes in species distributions, and understanding the mechanisms that underpin macroecological patterns is necessary for a more predictive science. Warming sea water temperatures are expected to drive changes in ectothermic marine species ranges due to their thermal tolerance levels. Here, we develop a mechanistic tool to predict size‐ and season‐specific distributions based on the physiology of the species and the temperature and food conditions in the sea. The effects of climate conditions on physiological‐based habitat utilization was then examined for different size‐classes of two commercially important fish species in the North Sea, plaice, Pleuronectes platessa, and sole, Solea solea. The two species provide an attractive comparison as they differ in their physiology (e.g. preferred temperature range). Combining dynamic energy budget (DEB) models with the temperature and food conditions estimated by an ecosystem model (ERSEM), allowed spatial differences in potential growth (as a proxy for habitat quality) to be estimated for 2 years with contrasting temperature and food conditions. The resulting habitat quality maps were in broad agreement with observed ontogenetic and seasonal changes in distribution as well as with the recent changes in distribution which could be attributed to an increase in coastal temperatures. Our physiological‐based model provides a powerful tool to explore the effect of climate change on the spatio‐temporal fish dynamics, predict effects of local or broad‐scale environmental changes and provide a physiological basis for observed changes in species distributions.     

Nutrient availability affected shallow-lake ecosystem response along the Late-Glacial/Holocene transition

In temperate headwater streams, intra-annual variation in energy input is critical in influencing aquatic food webs. We used stable isotope analysis to explore how seasonal variation in energy sources likely influenced invertebrate composition together with isotopic niche patterns of a cyprinid minnow, the chubbyhead barb Enteromius anoplus within a southern temperate headwater stream. Basal food sources had lower carbon and nitrogen stable isotope values in winter and spring compared to summer and autumn. Seasonal variations in the aquatic invertebrate communities were depicted by differences in the composition of gatherer and predator groups together with occurrence of scrapers in summer. Temporal changes in the isotopic values of these invertebrate groups appeared to coincide with that of basal food resources. The chubbyhead barb exhibited seasonal variation that was characterised by larger isotopic niches in winter compared to summer. Tissue-specific comparisons revealed larger isotope niche size based on fin tissue than muscle tissue during the cold period but comparable isotope niche sizes in the warm period. Contrasting inter-tissue isotopic niche patterns, the cold period suggested the likelihood of tissue physiological differences. Comparable isotopic niche patterns in summer and autumn suggested the possibility of synchronised physiological processes for both tissues. This suggested the potential for fin tissue as non-lethal alternative when inferring food web dynamics for this species.

     

Bird diversity patterns in Neotropical temperate farmlands: The role of environmental factors and trophic groups in the spring and autumn

Productivity, habitat heterogeneity and environmental similarity are of the most widely accepted hypotheses to explain spatial patterns of species richness and species composition similarity. Environmental factors may exhibit seasonal changes affecting species distributions. We explored possible changes in spatial patterns of bird species richness and species composition similarity. Feeding habits are likely to have a major influence in bird–environment associations and, given that food availability shows seasonal changes in temperate climates, we expect those associations to differ by trophic group (insectivores or granivores). We surveyed birds and estimated environmental variables along line‐transects covering an E‐W gradient of annual precipitation in the Pampas of Argentina during the autumn and the spring. We examined responses of bird species richness to spatial changes in habitat productivity and heterogeneity using regression analyses, and explored potential differences between seasons of those responses. Furthermore, we used Mantel tests to examine the relationship between species composition similarity and both the environmental similarity between sites and the geographic distance between sites, also assessing differences between seasons in those relationships. Richness of insectivorous birds was directly related to primary productivity in both seasons, whereas richness of seed‐eaters showed a positive association with habitat heterogeneity during the spring. Species composition similarity between assemblages was correlated with both productivity similarity and geographic proximity during the autumn and the spring, except for insectivore assemblages. Diversity within main trophic groups seemed to reflect differences in their spatial patterns as a response to changes between seasons in the spatial patterns of food resources. Our findings suggest that considering different seasons and functional groups in the analyses of diversity spatial pattern could contribute to better understand the determinants of biological diversity in temperate climates.     

Feeding behavior and differential absorption of biochemical components by the infaunal bivalve Mulinia edulis and the epibenthic Mytilus chilensis in response to changes in food regimes

We measured changes in the feeding rate and food absorption efficiency of two suspension feeding bivalves, cross-trasplanted between habitats with special emphasis on their capacity for differential absorption of biochemical components from their food supply. Mulinia edulis were moved from the intertidal zone to the subtidal zone, and Mytilus chilensis from the subtidal to the intertidal zone for a period of 7 days, and then compared with animal that had not been transplanted. Experimentally prepared diets similar to those available in the two different environments were offered to the bivalves, and their rates of feeding and differential uptake of biochemical components were determined and statistically compared. The two species did not achieve complete acclimation of their feeding behaviour during the transplant period since the highest ingestion rates for biochemical components occurred under dietary conditions that reflected their habitats of origin. Absorption efficiency showed greater acclimation than the other physiological parameters measured, indicating the capacity of these species to modulate their enzymatic-digestive activity depending on food composition. We conclude that both Mytilus and Mulinia have a certain degree of physiological plasticity in their feeding behaviour and assimilatory balance of biochemical components, being greater in Mytilus. When both species encounter ambient food conditions characteristic of their normal habitats, they show maximum values of food absorption, while under conditions where their typical diets are exchanged (Mytilus in intertidal and Mulinia in subtidal), the energy absorbed declines in each, but in ways very different between the two species. Thus, Mytilus exposed to high concentrations of low quality seston reduced the energy absorbed by 31.7% compared to its normal habitat, while Mulinia exposed to low concentrations of high-quality food reduced their energy absorption by 64%.     

Ecological correlates to activity and habitat use of two prosimian primates: Eulemur rubriventer and Eulemur fulvus rufus in Madagascar

In this paper, I provide data on the possible effects of group size and seasonal changes in food availability on the activity and habitat use patterns of two species of prosimian primate: the rufous lemur (Eulemur fulvus rufus) and the red-bellied lemur (Eulemur rubriventer). General and subtle seasonal differences were observed between lemur species in (1) group size and composition, (2) activity profiles, and (3) habitat use. Rufous lemur groups were larger (mean = 8 individuals) and contained more adults than red-bellied lemur groups (mean = 3 individuals). The overall degree and distribution of diurnal activity differed between lemur species and varied within species with seasonal changes in food availability. In general, rufous lemurs traveled more often than red-bellied lemurs. During food scarcity, both species increased the amount of time spent feeding, although peak feeding and traveling times differed. Both species also preferred horizontal substrates; however, during food scarcity, red-bellied lemurs used terminal branches more often while feeding than rufous lemurs. In addition, red-bellied lemurs used the lower middle story forest and rested in taller, upper canopy trees more often than rufous lemurs. Differences in activity and habitat use patterns between lemur species were more related to seasonal changes in food availability than overall differences in group size. These behavioral patterns may represent different strategies used by each lemur species to avoid directly competing for similar resources during times of food scarcity. © 1996 Wiley-Liss, Inc.     

Adjustment of metabolite composition in the haemolymph to seasonal variations in the land snail <Emphasis Type="Italic">Helix pomatia</Emphasis>

In temperate regions, land snails are subjected to subzero temperatures in winter and hot temperatures often associated to drought in summer. The response to these environmental factors is usually a state of inactivity, hibernation and aestivation, respectively, in a temperature and humidity buffered refuge, accompanied by physiological adjustments to resist cold or heat stress. We investigated how environmental factors in the microhabitat and body condition influence the metabolite composition of haemolymph of the endangered species Helix pomatia. We used UPLC and GC–MS techniques and analyzed annual biochemical variations in a multivariate model. Hibernation and activity months differed in metabolite composition. Snails used photoperiod as cue for seasonal climatic variations to initiate a physiological state and were also highly sensitive to temperature variations, therefore constantly adjusting their physiological processes. Galactose levels gave evidence for the persistence of metabolic activity with energy expenditure during hibernation and for high reproductive activity in June. Triglycerides accumulated prior to hibernation might act as cryoprotectants or energy reserves. During the last month of hibernation snails activated physiological processes related to arousal. During activity, protein metabolism was reflected by high amino acid level. An exceptional aestivation period was observed in April giving evidence for heat stress responses, like the protection of cells from dehydration by polyols and saccharides, the membrane stabilization by cholesterol and enhanced metabolism using the anaerobic succinic acid pathway to sustain costly stress responses. In conclusion, physiological adjustments to environmental variations in Helix pomatia involve water loss regulation, cryoprotectant or heatprotectant accumulation.     

Response of two species of clams, Ruditapes decussatus and Venerupis pullastra, to starvation: physiological and biochemical parameters

Adult specimens of two species of clams, Ruditapes decussatus and Venerupis pullastra, were starved for 84 days to determine the effect of starvation on their metabolism. The energy cost of metabolism in starvation was assessed using the oxygen consumption rates (respiration rates) of the clams and assessing the type of fuel used to provide this energy by analyzing their biochemical composition. Respiration rates decreased in both species after 15 days of starvation and remained at basal levels throughout the rest of the experimental period. Both during the first period and also after the metabolism had slowed down, the amount of energy consumed in respiration was higher in V. pullastra than in R. decussatus. The energy needed to maintain vital functions in both species is obtained from catabolism of body components, with a reduction in dry mass of the specimens, and consequently their energy content, in both species. This reduction was greater in V. pullastra given that energy demand is higher in this species. In both species carbohydrates made the largest contributions to energy output, followed by lipids in males and proteins in females. However, the energy contribution of each biochemical component differs according to species: R. decussatus obtains its energy from the catabolism of carbohydrates and proteins in equal proportion, while V. pullastra obtains it from proteins and lipids. In both species, albeit to a greater extent in R. decussatus, we observed that female specimens conserved their lipids until the later stages of the period of starvation (day 70), after which they started to metabolise their lipid components more intensely. The interspecific differences are interpreted in relation to the different habitat occupied by the two species.     

Effect of habitat quality on the ecological behaviour of a temperate-living primate: time-budget adjustments

Barbary macaques, like other non-human primates living in highly seasonal temperate environments, display high monthly variations in their diet. In addition, their diet changes according to the habitat type they colonize and to the degree of habitat degradation due to resource exploitation by local people, in particular through pastoralism. We studied the time-budget adjustments of wild Barbary macaques in three cedar–oak forests impacted by different intensities of grazing pressure from goats and sheep. We examined how diet variations influenced the time monkeys spent in their activities and their day range lengths (i.e. their energy costs). At three studied sites, diet composition and time budgets showed marked seasonal variations. Diet composition had a strong influence on monkeys’ time budget. In the forest where pastoralism was the highest, diet included a greater proportion of underground resources, shrub fruit and acorns, which led to an increase in the time spent foraging and moving, as well as an important increase in day range lengths. Energy costs were therefore higher in a degraded environment than in a suitable habitat. The monkeys living in forests subjected to pastoralism took advantage of increased day lengths to spend more time searching for food. However, in the forest with the highest pastoralism pressure, although monkeys spent more time foraging, they spent less time feeding than monkeys at the other sites. In addition, they appeared to have reached the limits of the available time they could devote to these activities, as their diurnal resting time was at its lowest level over several months. Temperature variations did not appear to modify monkeys’ time budgets. In the least favourable habitat, saving time from resting activity allowed monkeys to maintain a relatively high level of social activity, partly linked to rearing constraints.     

Food Resource Partitioning between Two Invasive Gobiid Species (Pisces,Gobiidae) in the Littoral Zone of the River Danube,Hungary

At present, the invasive round and bighead gobies are the most abundant benthic fish species in the near shore zone of the Middle Danube. We compared their diet seasonally in natural and artificial habitats and contrasted it with the food supply. The composition of the macroinvertebrate community was determined mainly by seasonal changes, whereas habitat type had smaller effect. Round gobies followed these changes flexibly. They consumed mainly chironomids in the spring, whilst amphipods and molluscs in the summer and autumn. Bighead gobies relied on amphipods in each season and in both habitats, and consumed fish, too, including round goby (intraguild predation). Diet overlap was determined by the morphological differences of the species allowing a varying degree of differentiation according to the seasonally changing food supply. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

热带珊瑚礁区海参的生境选择与生态作用

珊瑚礁生态系统是一个高生产力、高生物多样性的特殊海洋生态系统,具有为生物提供栖息地、参与生物地球化学循环、防浪护岸、指示水体污染程度等生态功能。珊瑚礁生态系统的突出特点是其生境异质性很高,各种各样的生境斑块为种类繁多、习性各异的游泳和底栖生物提供栖息场所,这些礁栖生物通过参与各项生态过程而形成各种特定的功能群,共同完成重要的生态功能。在热带珊瑚礁生态系统中,海参是大型底栖动物区系的重要一员。种类繁多的海参具有各自不同的生境选择特征,通过摄食、运动等行为活动发挥着改良底质、促进有机物矿化和营养盐再生等生态作用。近几年来,全球热带海参受人类过度捕捞和珊瑚礁退化的影响而面临资源衰退、物种多样性丧失等问题,深入认识其生态学功能、加强热带海参资源保护迫在眉睫。综述了国内外热带珊瑚礁海参的基础生态学研究进展：海参对珊瑚礁生境斑块呈现显著的偏好选择特征以及种间差异和季节变动,不同生境斑块的食物质量、底质类型和水动力条件是影响海参生境偏好的重要因素;海参通过生物扰动可以改变珊瑚礁生境沉积物的含水量、渗透性、颗粒组成、再矿化率、无机营养物质释放速率以及孔隙水的化学梯度,并增加沉积物中的溶氧浓度、促进溶解...     

The feeding ecology of a selective browser, the giraffe (Giraffa camelopardalis tippelskirchi)

A herbivore can manipulate certain factors of its feeding behaviour in order to achieve the metabolic requirements for reproduction. These factors include the choice of habitat in which to feed, the selection criteria for choosing food items, and the time allocated to feeding or devoted to other energy-consuming activities. The manipulation of these behavioural factors by giraffe in the Serengeti National Park, Tanzania is analysed in relation to the seasonal changes in the quantity and quality of the food resource.
The pattern of habitat choice demonstrates seasonal movements by giraffe across the drainage catena in response to differences in the rates of browse production between woodland types.
Giraffe show a positive inter-specific selection for the minor food items with a low available biomass, and utilize the dominant species in approximate proportion to their availability. Plant part selection is shown for the flushing shoots with very high protein contents.
Selection criteria include a significant selection for phosphorus, and in the dry season a selection for high energy material by breeding females. With the high nutritional qualities of the diets, negative criteria such as secondary chemical compounds are important. Patterns of browse selection are correlated with inter-specific seasonal changes in plant phenology.
Giraffe devote more time to foraging as the biomass and quality of the food declines in the dry season. Energy is conserved by minimizing energy-consuming activities at the most demanding times of day.     

Environmental gradients and the horizontal distribution of microcrustaceans in lakes

1. The assemblage of suspension‐feeding microcrustaceans in lakes changes along a habitat gradient from nearshore to offshore. This gradient of microcrustaceans was explored in relation to differences in macrophytes and the associated changes in water chemistry, food resources and types of predators.
2. Some microcrustacean species were littoral or limnetic specialists, while others changed their distribution along this horizontal habitat gradient on a diel or seasonal basis. Distribution patterns were similar in a lake and a pond which differed in extent of macrophyte habitat.
3. There was a large shift in the composition of sestonic food, indicating heterotrophic seston nearshore and more autotrophic seston offshore. Sit‐and‐wait predators of microcrustaceans (e.g. Enallagma spp.) dominated nearshore and cruising predators (e.g. Leptodora kindtii Focke) were more common offshore.
4. A reciprocal transplant experiment revealed that littoral specialists could survive equally well when fed littoral or limnetic seston, while limnetic specialists performed poorly when fed littoral seston. Food resources may be important in determining where some microcrustacean species live along this horizontal habitat gradient.     

拉沙山黑白仰鼻猴食用竹叶的化学成分分析

黑白仰鼻猴常年采食竹类叶片,竹子是其重要的食物资源之一。本文通过对拉沙山黑白仰鼻猴生境中空心箭竹和马斯箭竹竹叶化学成分进行分析,探讨其采食原由。2011年3月至2012年2月,共采集了21份竹子样品,分析其粗蛋白、粗脂肪、总糖、粗纤维、灰分、钙和总磷等化学成分。结果表明:两种竹叶的选择主要受高钙、高能量和低Ca/P的影响。尽管空心箭竹与马斯箭竹的化学成分无差异,但是影响黑白仰鼻猴食物选择的主要因素有所不同,这可能与竹子化学成分的季节性变化有关。结合前人对该猴群非竹类食物的研究结果,黑白仰鼻猴采取在满足蛋白质、脂肪等常量营养物质需求基础上优先保证磷、钙和能量摄入的觅食策略。竹类等猴群重要食物资源应该受到重点保护,同时也是未来食物资源恢复的首选物种。     

Changes and drivers of zooplankton diversity patterns in the middle reach of Yangtze River floodplain lakes,China

Anthropogenic habitat alteration interferes the natural aquatic habitats and the system''s hydrodynamics in the Yangtze River floodplain lakes, resulting in a serious decline in freshwater biodiversity. Zooplankton communities possess major position in freshwater ecosystems, which play essential parts in maintaining biological balance of freshwater habitats. Knowledge of processes and mechanisms for affecting variations in abundance, biomass, and diversity of zooplankton is important for maintaining biological balance of freshwater ecosystems. Here, we analyzed that the temporal and spatial changes in the structure of zooplankton community and their temporal and spatial variations respond to changes in environmental factors in the middle reach of Yangtze River floodplain lakes. The results showed that zooplankton samples were classified into 128 species, and Rotifera was the most common taxa. Significant seasonal differences were found among the abundance and diversity of zooplankton. Similarly, we also found significant seasonal differences among the biomass of zooplankton functional groups. The spatial turnover component was the main contributor to the β diversity pattern, which indicated that study areas should establish habitat restoration areas to restore regional biodiversity. The NMDS plot showed that the structure of zooplankton community exhibited significant seasonal changes, where the community structure was correlated with pH, water temperature, water depth, salinity, total nitrogen, chlorophyll‐a, and total phosphorus based on RDA. This study highlights that it is very important to ensure the floodplain ecosystem''s original state of functionality for maintaining the regional diversity of the ecosystem as a whole.     

Seasonal variations in the intermediate metabolism of Parastacus varicosus (Crustacea, Decapoda, Parastacidae)

The aim of this study was to analyze the seasonal variations in the metabolism of Parastacus varicosus and examine the possible relationships to its reproduction. Animals were sampled (9 h to 10 h) in each month in the Gravataí River, RS, Brazil. Haemolymph samples were collected from each crayfish in the field for determination of glucose, total proteins, total lipids, and total cholesterol. Hepatopancreas, abdominal muscle, and gonads were removed for determination of glycogen, total proteins, total lipids, and total cholesterol. ANOVA revealed significant seasonal differences in the biochemical composition of all tissues studied; when the sexes were compared these parameters did not show any significant difference in the hepatopancreas and muscle. However, in haemolymph we observed significant variation only in cholesterol and lipid levels. The results suggest that the metabolic variability is related to the stage of maturation of the gonads, in females, where the hepatopancreas and other tissue studies can store and transfer reserves to support maturation to complement the food intake. Variations in the gonadosomatic and hepatosomatic indices suggest that reproduction occurs principally in summer. As in other decapods, abiotic factors such as water temperature, oxygen content, etc. influence the intermediate metabolism.     

Food diversity and choice of white-headed langur in fragmented limestone hill habitat in Guangxi,China

We studied the diet and food choice of three groups of white-headed langurs (Trachypithecus leucocephalus) from July 2002 to June 2003 at Fusui Rare Animal Reserve, Guangxi, China. Data were collected from via focus group sampling, with continuous recording. A total of 109 plant species (including 19 unidentified species) were used as food by the white-headed langur. They spent 91.6% of total feeding time feeding on leaves, 4.2% on fruits and 3.3% on stems. Flowers and other food items accounted for only 0.3% and 0.6% of total feeding time, respectively. There were significant seasonal variations in the langurs’ diets with changes in the total number of species and the diversity of food species consumed. The langurs used significantly more plant species as food in the rainy season than in the dry season (36 species vs. 26.5 species). Dietary diversity was also significantly higher in the rainy season than in the dry season (2.6 vs. 2.4). No significant seasonal variation was found in the percentage of various plant parts in their monthly diets. Though the white-headed langur fed on many plant species, 11 species made up 84.9% of their diet. There were no significant correlations between the percentage of feeding time for main food plant species and their corresponding abundance in the habitat, content of water, crude protein, crude fiber and the ratio of crude protein to crude fiber. These results suggest that food choice of the white-headed langur is not influenced by their abundance and nutritional content.     

Advances in understanding the impacts of global warming on marine fishes farmed offshore: Sparus aurata as a case study

Monitoring variations in proteins involved in metabolic processes, oxidative stress responses, cell signalling and protein homeostasis is a powerful tool for developing hypotheses of how environmental variations affect marine organisms' physiology and biology. According to the oxygen- and capacity-limited thermal tolerance hypothesis, thermal acclimation mechanisms such as adjusting the activities of enzymes of intermediary metabolism and of antioxidant defence mechanisms, inducing heat shock proteins (Hsps) or activating mitogen-activated protein kinases may all shift tolerance windows. Few studies have, however, investigated the molecular, biochemical and organismal responses by fishes to seasonal temperature variations in the field to link these to laboratory findings. Investigation of the impacts of global warming on fishes farmed offsore, in the open sea, can provide a stepping stone towards understanding effects on wild populations because they experience similar environmental fluctuations. Over the last 30 years, farming of the gilthead sea bream Sparus aurata (Linnaeus 1758) has become widespread along the Mediterranean coastline, rendering this species a useful case study. Based on available information, the prevailing seasonal temperature variations expose the species to the upper and lower limits of its thermal range. Evidence for this includes oxygen restriction, reduced feeding, reduced responsiveness to environmental stimuli, plus a range of molecular and biochemical indicators that change across the thermal range. Additionally, close relationships between biochemical pathways and seasonal patterns of metabolism indicate a connection between energy demand and metabolic processes on the one hand, and cellular stress responses such as oxidative stress, inflammation and autophagy on the other. Understanding physiological responses to temperature fluctuations in fishes farmed offshore can provide crucial background information for the conservation and successful management of aquaculture resources in the face of global change.