Jen Kelley, Gwen Rodgers and I have just published a new paper on the conflict between background matching and social signalling in western rainbowfish (Melanotaenia australis). We’d previously found that these fish change their skin coloration in response to their background, and investigated whether this colour change for background matching influenced aggressive interactions between males. We found that subordinate males received increased aggression from dominants when they had recently darkened their skin for background matching relative to subordinates that had not darkened. We then showed that dominant males darkened more than subordinates when placed in a tank with a dark background, but when their social statuses were reversed, both dominants (who had previously been subordinate) and subordinates (who had previously been dominant) darkened less. Overall, we suggest that skin darkening can carry a social cost for subordinate males, and the use of skin colour in social interactions can affect its later use in other functions, like background matching.
This paper was based on data that Gwen collected, with Jen, in 2011. It’s been a long time!
Reference: Kelley, JL, Rodgers, GM & Morrell, LJ. (2016) Conflict between background matching and social signalling in a colourful freshwater fish. Royal Society open science 3: 160040 [open access]