Prospecção da biodiversidade críptica e padrões biogeográficos em peixes do litoral e ilhas oceânicas do Atlântico Ocidental

Abstract

The extensive Brazilian coast is multi-party in different ecosystems, composed by estuaries, mangroves, reef systems, oceanic and coastal islands. These environments detain a largely diversified ichthyofauna composed by 1,297 species, in which 25% represents endemic species. These levels of biodiversity can be uncertain, because of the occurrence of cryptic and polytypic species and the absence of population studies, especially in reef species. In this sense, population, taxonomical and phylogenetical aspects were analyzed form species of the Pomacentridae (Perciformes) and Carangidae (Carangiformes) families, along the coast and oceanic islands of Brazil. The molecular and morphometric analyzes were performed in S. variabilis, S. fuscus, S. rocasensis, S. sanctipauli and S. fuscus trindadensis indicated synonym among S. rocasensis and S. sanctipauli, and between S. fuscus and S. fuscus trindadensis. Besides that, revealed the presence of a possible cryptic species which has been confused with S. variabilis. The population analyzes in Abudefduf saxatilis at the Western Atlantic, including the oceanic islands, reveals a status of panmixia from Venezuela to the Southeast of Brazil, while the island populations have different levels of genetic structuration, specially the population of the Trindade island. The genetic analyzes in the polytypic species Caranx lugubris indicated a large panmitic population in the Western Atlantic, revealing new data about the origins of the morphotypes that occurs in the surroundings of the Saint Paul Rocks archipelago. The data obtained expands the knowledge over the insular ichthyic fauna of the Atlantic and serves as subsidy to the conservation and management of species of these particular and important oceanic regions.