Body color and skin spot patterning. Their relationship with stress coping style in rainbow trout.




North Jutland

In aquaculture, there are different inherent factors that may induce stress in farmed fish (handling, alterations of water quality, diseases, noise, etc.) affecting the growth/survival of the fish and consequently, reducing productivity. For a given fish species, individuals differ in the way they react when facing novel or stressful situations (stress coping style, SCS). In this regard, some individuals are naturally/genetically less vulnerable to stress and can tolerate common aquaculture stressors to a larger extent before their welfare becomes compromised. It has been suggested for salmonids that, to a certain extent, skin pigmentation could be related to stress coping style, and some studies have shown a negative correlation between the number of melanin spots in the skin and the intensity of the stress response of the fish: fish showing proactive behavioral traits (social dominance, boldness) tend to have more melanin spots and a stress response of lower intensity, while fish showing reactive behavioral traits (social subordination, shyness) tend to display less melanin skin spots and a stress response of higher intensity. The objectives of the present project are:

1) To determine whether stress sensitivity can be predicted from melanin skin spot patterning and/or skin background color in farmed rainbow trout.

2) To evaluate skin pigmentation as an approach for the early selection of more robust individuals against stress and disease in trout aquaculture.

The experimental work will be carried out in Hirtshals and will consist of different experiments directed to select groups of fish differing in skin pigmentation, which will then be used in different trials to assess their sensitivity to aquaculture-related stressors. The student will be involved in all stages of the study: experimental design, experimental protocols, sampling, biochemical and behavioral analyses, data analysis and evaluation, and writing of reports.


Dedicated student with interest in fish physiology and relevant background regarding courses related to fish physiology and/or general stress physiology

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Company / Organization

DTU Aqua


Manuel Gesto




Supervisor info

MSc in Aquatic Science and Technology


Manuel Gesto

ECTS credits

30 - 35


MSc thesis

Technical University of Denmark

For almost two centuries DTU, Technical University of Denmark, has been dedicated to fulfilling the vision of H.C. Ørsted – the father of electromagnetism – who founded the university in 1829 to develop and create value using the natural sciences and the technical sciences to benefit society.

Today, DTU is ranked as one of the foremost technical universities in Europe, continues to set new records in the number of publications, and persistently increases and develops our partnerships with industry, and assignments accomplished by DTU’s public sector consultancy.

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