Melanin-based skin spots reflect stress responsiveness in salmonid fish

Kittilsen, S.; Schjolden, J.; Beitnes-Johansen, I.; Shaw, J.C.; Pottinger, T.G.; Sorensen, C.; Braastad, B.O.; Bakken, M.; Overli, O.. 2009 Melanin-based skin spots reflect stress responsiveness in salmonid fish. Hormones and Behavior, 56 (3). 292-298.

This is the latest version of this item.

Before downloading, please read NORA policies.
KittilsenN007671PP.pdf - Accepted Version

Download (301kB)


Within animal populations, genetic, epigenetic and environmental factors interact to shape individual neuroendocrine and behavioural profiles, conferring variable vulnerability to stress and disease. It remains debated how alternative behavioural syndromes and stress coping styles evolve and are maintained by natural selection. Here we show that individual variation in stress responsiveness is reflected in the visual appearance of two species of teleost fish; rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). Salmon and trout skin vary from nearly immaculate to densely spotted, with black spots formed by eumelanin-producing chromatophores. In rainbow trout, selection for divergent hypothalamus-pituitary-interrenal responsiveness has led to a change in dermal pigmentation patterns, with low cortisol-responsive fish being consistently more spotted. In an aquaculture population of Atlantic salmon individuals with more spots showed a reduced physiological and behavioural response to stress. Taken together, these data demonstrate a heritable behavioural-physiological and morphological trait correlation that may be specific to alternative coping styles. This observation may illuminate the evolution of contrasting coping styles and behavioural syndromes, as occurrence of phenotypes in different environments and their response to selective pressures can be precisely and easily recorded.

Item Type: Publication - Article
Digital Object Identifier (DOI):
Programmes: CEH Programmes pre-2009 publications > Water
UKCEH and CEH Sections/Science Areas: Parr
ISSN: 0018-506X
Additional Information. Not used in RCUK Gateway to Research.: The definitive version of this article is available from
Additional Keywords: stress, behaviour, pigmentation, rainbow trout, salmonid, selective breeding, cortisol, coping style
NORA Subject Terms: Biology and Microbiology
Ecology and Environment
Related URLs:
Date made live: 06 Oct 2009 09:30 +0 (UTC)

Available Versions of this Item

  • Melanin-based skin spots reflect stress responsiveness in salmonid fish. (deposited 06 Oct 2009 09:30) [Currently Displayed]

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...