Stress and Wellfare
Fish reared under intensive culture conditions are subjected to several environmental, social, and husbandry related stimuli that may have potentially noxious or stressful effects. Following exposure to a stressor, fish undergo a series of neuroendocrine, biochemical, physiological and behavioural changes as a coping mechanism. The fish's response to stressors may be of either an adaptive nature, allowing for homeostatic recovery, or a maladaptive nature having adverse effects on survival, growth, immune response, reproductive capabilities, behaviour and general fitness. Although most fish follow a generalized motif of stress response, with increased concentrations of cortisol, glucose and lactate, there is species-specificity in the pattern and magnitude of the response, as well as in stress tolerance. We focus on the characterization of the stress response in several important for aquaculture marine species and on the development of reliable welfare indicators. Main questions are:
- How coping styles are linked with the stress response and important performance traits?
- How early stress affect fish performance at subsequent phases of development?
- How can we define the allostatic load and overload under intensive aquaculture conditions?
- Are there any reliable operational welfare indicators?
- How coping styles are linked with the stress response and important performance traits?
- How early stress affect fish performance at subsequent phases of development?
- How can we define the allostatic load and overload under intensive aquaculture conditions?
- Are there any reliable operational welfare indicators?
Pigmentation Physiology
Fishes display a variety of skin coloration patterns which are of great ecological, physiological and behavioural importance. Skin pigmentation pattern can be also considered as an index of animal welfare in aquaculture species and a factor of economical consideration. Several fish, such as the red sea bream (Pagrus major) and the red porgy (Pagrus pagrus), that are coloured in nature acquire darker coloration under intensive rearing conditions. We focus on the identification of the factors that contribute to skin dispigmentation and the means to overcome this problem.
- How environmental (light intensity, lighting spectrum, water temperature, salinity, nutrition) and husbandry factors (tank colour, stocking density, sea cage's depth, handling) affect skin pigmentation in the red porgy?
- How the endocrine system (cortisol, α-MSH, thyroid hormones, catecholamines) regulate physiological and morphological colour changes in Mediterranean marine fish?
- How environmental (light intensity, lighting spectrum, water temperature, salinity, nutrition) and husbandry factors (tank colour, stocking density, sea cage's depth, handling) affect skin pigmentation in the red porgy?
- How the endocrine system (cortisol, α-MSH, thyroid hormones, catecholamines) regulate physiological and morphological colour changes in Mediterranean marine fish?
Reproductive Physiology
Mastery of the reproductive cycle and spawning control is a prerequisite for aquaculture to complete the production cycle of a given fish species. My research (1991 – 2002) was focused, (a) on the hormonal and environmental control of spawning and of several fish species (rainbow trout, Onchorhynchus mykiss; gilthead sea bream, Sparus aurata; European sea bass, Dicentrarchus labrax; sharpsnout sea bream, Diplodus puntazzo; red porgy, Pagrus pagrus; common dentex, Dentex dentex) in captivity and (b) on the investigation of Temperature-Dependent Sex Determination mechanism in the European Sea Bass.
Recently, we work on the molecular and endocrine mechanisms regulating early ontogeny in several marine teleosts, with emphasis on the role of thyroid and glucocorticoids hormones.
Recently, we work on the molecular and endocrine mechanisms regulating early ontogeny in several marine teleosts, with emphasis on the role of thyroid and glucocorticoids hormones.
