The association of the goatfish mulloidichthys martinicus with the grunt haemulon chrysargyreum: an example of protective mimicry

Abstract

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. Key words: Protective mimicry, social mimicry, mixed schooling, Mulloidichthys martinicus, Haemulon chrysargyreum. ResumoDescrevemos aqui um possível exemplo de mimetismo de proteção entre o saramunete Mulloidichthys martinicus (Mullidae) e a xira Haemulon chrysargyreum (Haemulidae), no Arquipélago de Fernando de Noronha, Nordeste do Brasil. O saramunete e a xira são semelhantes entre si, no padrão de coloração e no formato do corpo. Observamos que estas duas espécies formam cardumes mistos regularmente, ao redor de recifes. Quando perseguidos, pequenos grupos isolados de saramunetes se associam aos cardumes de xira e se comportam de modo semelhante às xiras. As semelhanças de formato e coloração entre as duas espécies provavelmente facilitam a formação de cardumes mistos e aumentam a proteção contra predadores visualmente orientados, para ambas as espécies. Assim, acreditamos que a associação protetora entre o saramunete e a xira pode ser considerada como um tipo de "mimetismo social", uma vez que nenhuma destas espécies é venenosa, peçonhenta ou tem fortes estruturas mecânicas de defesa. Sugerimos, ainda, que exemplos adicionais de mimetismo social possam envolver o saramunete e outras espécies listradas de Haemulon. Palavras-chave:Mimetismo de proteção, mimetismo social, cardumes mistos, Mulloidichthys martinicus, Haemulon chrysargyreum.Biota Neotropica v4 (n2) http://www.biotaneotropica.org.br/v4n2/pt/abstract?shortcommunication+BN02704012004

Mixed-species schooling behavior and protective mimicry involving coral reef fish from the genus Haemulon (Haemulidae)

“…In the case of the association of Harengula clupeola with Haemulon aurolineatum and H. squamipinna, both conditions were evidenced, as this species closely resembles these grunts, and feeds mainly on copepods, crustacean larvae, and diatoms (Ortaz et al, 1996;Chaves & Vendel, 2008), demonstrating great diet similarities with the plankton-feeding Haemulon juveniles (Estrada, 1986;Pereira & Ferreira in prep.). Krajewski et al (2004) studied protective mimicry involving H. chrysargyreum and the goatfish Mulloidichthys martinicus and suggested that the observed interactions might occur among other striped Haemulon species, which was confirmed by the present study, reporting this type of behavior involving M. martinicus with Haemulon aurolineatum and H. squamipinna, both examples of striped grunts. This goatfish was also sighted in association with Haemulon flavolineatum and H. plumieri near the Virgin Islands in the Caribbean (Ogden & Ehrlich, 1977).…”

Patterns of variation in behaviour within and among reef fish species on an isolated tropical island: influence of exposure and substratum

“…Although each pair consists of species of the same trophic group, family, and even the same genus, they are very different in their behaviour. Haemulon chrysargyreum and M. martinicus , for example, are more similar to each other than to species of their own families, which is probably because they may also be nocturnal, and sometimes remain inactive in the water column during the day (Randall, 1967; Krajewski et al , 2004, 2006). Thus, common evolutionary history and trophic ecology are not prerequisites nor necessarily imply that species behave similarly as neither have similar functional roles on the reefs (Sazima, 1986).…”

The almost invisible league: crypsis and association between minute fishes and shrimps as a possible defence against visually hunting predators

“…For fishes the best known examples came from studies on reef fishes (e.g. Dafni & Diamant, 1984;Randall & McCosker, 1993;Krajewski et al, 2004), whereas records of such associations in freshwater seem to be lacking. We present here three instances of crypsis and association between freshwater fishes and shrimps which apparently rely on camouflaging colour pattern and transparency to evade some of their potential predators.…”