Coral reef fish association and behaviour on the fire coralMilleporaspp. in north-east Brazil

Abstract

The branching structure of the coral colonies from the genusMilleporaprovides substrate, shelter, and food resources for several reef organisms, such as fish and invertebrates. The present work analysed the association and behaviour of reef fish on the fire coralMillepora alcicornisandM. brasiliensisfrom September 2010 to February 2011, on the coastal reefs of Tamandaré, north-east Brazil. A total of 473 reef fish individuals of 27 species were sighted associated with the coral colonies, mainly composed of juveniles (65%). The most frequently observed behaviours were sheltered/stationary and swimming close to the coral; however, individuals were also observed foraging and breeding amongMilleporaspp. branching colonies. The agonistic behaviour performed byStegastes fuscusindividuals was highlighted in the present study, especially againstChaetodon striatus, Diodon holacanthusandOphioblennius trinitatisindividuals.Milleporaspp. hydrocorals are ecologically important for juvenile and adult reef fish belonging to several trophic guilds. The complex structure of the coral colonies provides a wide variety of ecological functions on coral reefs (e.g. shelter, reproduction area, food and even territory). Nevertheless, the abundance of branching fire coral in Brazilian reefs have been declining over the past years; therefore, efforts must be made to protect this key habitat.