Nivel invasivo de la especie exótica Neopomacentrus Cyanomos (bleeker, 1856) (Pomacentridae) dentro de la ictiofauna asociada a corales Orbicella spp. (Scleractinia: Merullinidae) en el arrecife en medio, sistema arrecifal Lobos-Tuxpan

Resumen

Biological monitoring is important for assessing the invasive level of alien species. Therefore, in the present work, the abundance of the exotic fish Neopomacentrus cyanomos was estimated with respect to the native ichthyofauna of the Enmedio reef, Veracruz. Five sampling sites were established on the leeward slope, a reef zone characterized by massive corals; in each place, the richness and abundance of native and exotic fishes were estimated in colonies of Orbicella annularis and Orbicella faveolata. The estimated community attributes were specific wealth, abundance, equitability index, and true diversity. To detect significant differences or similarities in the fish community structure, multivariate techniques were applied: similarity and ordering analysis. A total of 39 species of native fish and two exotic species were recorded: Neopomacentrus cyanomos and Pterois volitans. The most abundant species were Halichoeres burekae and Chromis multilineata, which constituted 89% of the total abundance. In contrast, Neopomacentrus cyanomos presented small populations <15 ind/coral and was common in O. faveolata. In the O. faveolata corals, 39 taxa were found and in O. annularis 35; however, fish abundance was higher in colonies of O. annularis than in O. faveolata. The ichthyofauna was characterized by the dominance of zooplanktophagous fishes; equitable and true diversity were higher in areas with greater coral cover and decreased at places where sand and coral pavements prevail. The ichthyofauna was similar in composition and abundance in O. annularis and O. faveolata as well as between the sampling sites. The small populations of N. cyanomos suggest that it is not a competitive species to the native ichthyofauna; however, it is necessary to continue monitoring in order to assess changes in abundance. In addition, it is imperative to investigate the status of invasion in the other reefs of Veracruz.