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Additional file 1. Supplementary figures.

The occurrence of emotions in non-human animals has been the focus of debate over the years. Recently, an interest in expanding this debate to non-tetrapod vertebrates and to invertebrates has emerged. Within vertebrates, the study of emotion in teleosts is particularly interesting since they represent a divergent evolutionary radiation from that of tetrapods, and thus they provide an insight into the evolution of the biological mechanisms of emotion. We report that Sea Bream exposed to stimuli that vary according to valence (positive, negative) and salience (predictable, unpredictable) exhibit different behavioural, physiological and neuromolecular states. Since according to the dimensional theory of emotion valence and salience define a two-dimensional affective space, our data can be interpreted as evidence for the occurrence of distinctive affective states in fish corresponding to each the four quadrants of the core affective space. Moreover, the fact that the same stimuli presented in a predictable vs. unpredictable way elicited different behavioural, physiological and neuromolecular states, suggests that stimulus appraisal by the individual, rather than an intrinsic characteristic of the stimulus, has triggered the observed responses. Therefore, our data supports the occurrence of emotion-like states in fish that are regulated by the individual’s perception of environmental stimuli. info:eu-repo/semantics/publishedVersion

Tese de doutoramento, Ciências Biológicas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016 Intensive aquaculture practices frequently expose fish to a range of stressors. Gilthead seabream (Sparus aurata) is the most important farmed species in the Mediterranean, and like in other vertebrates, exhibit pronounced individual differences in stress responsiveness, however to which extent such variability is part of coping styles remains unclear. As such, this Thesis aimed to provide methods and tools to analyse coping styles in seabream, with specific reference to the presence, variability and consistency of individual trait correlations relevant to fish welfare. Using an evolutionary approach, it integrated and explored the adaptive links between behaviour, physiology and brain function, especially aiming to explore individual variation in adaptive responses of seabream when exposed to the same stressful situation. The background and consequences of coping styles in aquaculture is introduced in Chapter 2. Chapter 3 aims to quantify individual differences in cortisol response in seabream and to assess whether it can predict aggressive behaviour. Results provided the first evidence for a link between HPI responsiveness and aggressive behaviour in seabream. This suggests that individual differences in aggression are part of coping styles and therefore can be predictive of and predicted from other traits. In Chapter 4, it was investigated, for the first time in seabream, whether individual differences in behavioural responses to a variety of challenges are consistent over time and across contexts using both individual and grouped-based tests. Results suggest consistency over time and across-context in behavioural responses to challenges both using individual and grouped-based tests. This study highlights the possibility to predict behaviour in groups from individual coping traits. One of the traits that has been shown to be consistent over time and across context in the Chapter 4 was the escape response under a restraining test. Using this trait as a proxy of coping styles in seabream the consistency of escape behaviour was investigated in Chapter 5 and 6. In Chapter 5 we investigated the effect of avoidance in gilthead seabream kept under different social contexts, i.e. the influence of other group members on individual avoidance behaviour consistency. The results demonstrate that grouping individuals with similar coping styles induces changes in coping styles whereas grouping individuals with different coping styles favours coping styles to remain the same. These findings suggest an influence of the social environment in seabream coping styles. In Chapter 6 we investigate the long term consistency of coping styles both, over time and during different life history stages. Our results show consistent behaviour traits in seabream when juveniles, and a loss of these behavioural traits when adults. Therefore, these results underline that adding a life history approach to data interpretation is as an essential step forward towards understanding coping styles. Chapter 7 aimed to characterize the stress coping ability and brain function in seabream, by investigating the behavioural and forebrain physiological responses of fish displaying contrasting coping styles to the same stimulus (escape response under a restraining test). Results show differences in activation of region-specific telencephalic regions between seabream displaying contrasting coping styles. It confirms the hypothesis that in seabream, inhibitory and excitatory markers of neural function appear to be associated with reactive and proactive coping styles, respectively. The main findings of this thesis are discussed and the main conclusions are presented in Chapter 8. It is concluded that fish with contrasting stress coping styles show clear differences in behavioural and physiological parameters. Moreover, these differences can change according to social environment and life history. In general this Thesis has generated new knowledge of the mechanisms underlying individual responses of fish to stress providing new insights on the interrelations between different relevant husbandry practices, fish performance and welfare.

The present work examined the short- and long-term effects of three rearing temperatures on protein metabolism and growth trajectories of Senegalese sole larvae using 14C-labelled Artemia protein as feed. A first feeding trial was performed on larvae reared at 15, 18 and 21 °C (at 26, 17 and 14 days post-hatching (dph), respectively) and a second trial conducted on post-larvae after transfer to the same rearing temperature (~20 °C) (49, 35 and 27 dph, in larvae initially reared at 15, 18 and 21 °C, respectively). Temperature greatly influenced larvae relative growth rate (RGR) and survival, since growth at 15 °C was severely depressed. Protein digestibility and retention was highest at 18 °C during the first trial (85.35 ± 1.16 and 86.34 ± 2.33 %, respectively). However, during the second trial, post-larvae from 15 °C had the highest feed intake and protein digestibility (3.58 ± 1.54 and 75.50 ± 1.35 %, respectively), although retention was similar between treatments. Furthermore, after transfer to 20 °C larvae from 15 °C experienced compensatory growth, which was observed until 121 dph, and confirmed by RGR values, which were significantly higher at 15 ºC than at 21 ºC or 18 ºC. Results from the present study show that Solea senegalensis larval development, survival and protein digestion and retention are highly affected by thermal history.

Dissertação mest., Aquacultura e Pescas, Universidade do Algarve, 2009 The general aim of this study was to understand the underlying factors responsible for the individual variation in growth of juvenile Senegalese sole (Solea senegalensis). Senegalese sole is a species of high commercial value and high interest for aquaculture in Europe, therefore it would be important to understand these individual variations. Understanding the causes for individual variation in growth in relation with the feed intake, metabolic rate and response to stress contributes to maximize the production efficiency by reducing food waste and improving water quality. In order to identify the possible factors responsible for the individual variation in sole growth, its relationship with metabolic rate, stress response and feed intake was determined. Twelve fish with 18.49 ± 2.94g of initial weight were kept in standard conditions and feed once a day, during a period of six months. Individual oxygen consumption measurements in Sole juveniles were determined by flow-through respirometry at standard conditions, after the fish were fed a single meal and after a stressful condition. Blood samples for plasma cortisol, were taken from all fish at the start of the experiment (control, indicative of basal levels) and after stress exposure. Quantification of individual feed intake was performed by incorporation with radio-opaque ballotinis glass beads in a dry feed, followed by radiography to quantify the amount of ingested pellets. Individual fish exhibited pronounced variation in growth (final weight ranging from 30.45 to 67.53g), oxygen consumption of fasted fish (108.0 to 447.4 μmol/g/h), oxygen consumption of fed fish (174.7 μmol/g/h to 813.5 μmol/g/h), oxygen consumption after emersion stress (186.8 μmol/g/h to 376.7 μmol/g/h), and plasma cortisol after emersion stress (4.81 ng/ml to 46.45 ng/ml). Individual differences in metabolic rate do not contribute to explain individual differences in growth. However, after emersion stress individual differences in stress response seem to play a role in explaining individual differences in growth, what may result from different copying styles. Sole feed intake as measured by X-ray does not seem to be a good indicator of growth rate. The oxygen consumption increases both when fish are fed and after an emersion stress, as result of additive costs of growth and stress to the cost of maintenance. All together, this study suggests that individual variation of growth in Solea senegalensis is essentially due to genetic variation, and its reduction may accomplished when genetic selection programs are adopted. Furthermore, a study with a larger number of fish and over a larger time period would be important to check some of the trends found in this thesis between growth potential, metabolic rate and coping styles of Senegalese sole.