The dusky dottyback (Pseudochromis fuscus) is a small fish that lives on coral reefs from India to the Pacific Islands. It feeds on juvenile damselfish that are either yellow or brown, depending on the reef. The dottyback can change its skin color to match that of the damselfish parents, allowing it to more readily ambush their young. A close-up view of a dottyback caught in the act of changing color shows a mix of yellow and brown skin cells. It takes about two weeks for a yellow dottyback to turn brown on a reef inhabited predominantly by brown damselfish or for a brown dottyback to turn yellow on a reef predominantly inhabited by yellow damselfish. Moreover, damselfish are very well camouflaged on their natural habitat and the ability of the dottyback to mimic the damselfish also provides it with a similar advantage protecting it from bigger predators such as the coral trout.
World Oceans Day is June 8th.
The image shows a micrograph of dottyback skin enlarged 40 times.
Fabio Cortesi, PhD, Zoological Institute, University of Basel, Switzerland and Queensland Brain Institute & School of Biological Sciences, University of Queensland, Brisbane, Australia.