Analysis of Nemertea diversity on the Southeast Brazilian coast

Abstract

Nemertea is a phylum of invertebrate animals characterized by an eversible proboscis lied in a coelomic cavity, the rhynchocoel. Due to the limited number of diagnostic morphological characters and adaptive convergence in some taxons, cryptic species complexes are found. In this context, molecular analyzes have been widely used to delimit species, allowing to evaluate the relationship between and within the morphotypes. Demographic and geographical factors have great influence on the distribution and connectivity between populations of nemertine species. Bionomic characteristics, such as reproductive mode, also play an important role in patterns of gene flow among natural populations. Studies involving all of these factors are scarce and, so far, none have been carried out with nemertea, an ecologically important group of wide distribution. Study the gene flow patterns in species of nemertea with varied dispersing capacities is essential for a better understanding of the history of their populations and each species. The species Lineus sanguineus, Prosorhochmus sp and Nemertopsis cf. bivittata have wide distribution on the Brazilian coast and different types of development. (AU)