Molecular and morphometric data pinpoint species boundaries in Halimeda section Rhipsalis (Bryopsidales, Chlorophyta)

Abstract

Molecular systematic studies have changed the face of algal taxonomy. Particularly at the species level, molecular phylogenetic research has revealed the inaccuracy of morphology-based taxonomy: Cryptic and pseudo-cryptic species were shown to exist within many morphologically conceived species. This study focused on section Rhipsalis of the green algal genus Halimeda. This section was known to contain cryptic diversity and to comprise species with overlapping morphological boundaries. In the present study, species diversity within the section and identity of individual specimens were assessed using ITS1-5.8S-ITS2 (nrDNA) and rps3 (cpDNA) sequence data. The sequences grouped in a number of c..