A presumed example of protective mimicry between the yellow goatfish, Mulloidichthys martinicus (Mullidae) and the smallmouth grunt, Haemulon chrysargyreum (Haemulidae) is described from Fernando de Noronha Archipelago, NE Brazil. The goatfish and the grunt share a similar overall shape and colour pattern. We found that these two species regularly form mixed schools around reefs. Additionally, when chased small groups of yellow goatfish join schools of smallmouth grunts and behave like them. The colour and shape resemblances between the two species enable their mixed schooling, and enhance the protection against visually oriented predators for both of them. Thus, we suggest that the protective association herein reported for the goatfish and the grunt may be considered as a “social mimicry”, since neither species is venomous, poisonous or strongly armed. Furthermore, we suggest that additional instances of social mimicry may involve the yellow goatfish and other striped Haemulon species.
Protective mimicry; social mimicry; mixed schooling; Mulloidichthys martinicus; Haemulon chrysargyreum