Estrutura populacional e distribuição de Mussismilia hispida (Verril, 1902) próximo ao limite sul de distribuição SW Atlântico (baía da Ilha Grande)

Abstract

Due to its high ecological and economic relevance, serving as mainstay and subsistence for coastal area populations, reef environments are considered to be one of the most important marine habitats. In this study we investigate the areas of occurrence in Baía da Ilha Grande (BIG) of reef coral Mussismilia hispida (Verril, 1902), one endemic species from Brazil. For that purpose, the Reef Check Brasil methodology was used, which consisted of three 30-meter long by 1-meter wide transects in each location under study, at the depths of 3, 5 and 8 meters. The density of colonies and population structure based on size were evaluated. Vertical transects were also conducted to establish the relation between the substrate profile and colony density and distribution. A total of 38 transects in 11 sites throughout BIG were performed and we observed that the species is preferably distributed at the 8-meter depth predominantly with small colonies (up to 20 centimeters in diameter). The highest colony density are reported to Lagoa Verde and Jorge Grego sites, which are farther from the coast and with many rocky blocks that interfere with the distribution and morphometry of the colonies. Despite the fact that several studies in Brazil have included M. hispida as the studied species, we bring new data for the Brazilian coast and which could direct future studies.