First there was the octopus that mimicked fish; now researchers say a fish is copying the octopus.
The mimic octopus is known to impersonate lionfish and sea snakes by adapting their movement and colour.
But scientists from the University of Gottingen, Germany, have now recorded a black-marble jawfish disguising itself among the octopus' tentacles.
The confusing circle of imitation was observed in waters off the coast of Indonesia.
In findings published in the journal Coral Reefs, scientists say this is the first evidence of the unusual association between a fish and a mimic octopus (Thaumoctopus mimicus).
The jawfish (Stalix cf. histrio) is described as a timid species, more commonly found close to its sandy burrow on the sea floor.
Godehard Kopp who photographed the scene, sent his evidence to experts at the California Academy of Sciences for identification.
"This is a unique case in the reefs not only because the model for the jawfish is a mimic itself, but also because this is the first case of a jawfish involved in mimicry," said Dr. Luiz Rocha, assistant curator of ichthyology at the California Academy of Sciences in San Francisco.
The researchers suggest that the jawfish is an "opportunistic mimic"; disguising itself in order to use the octopus as protection while it forages for food.