Deviant segments hamper a morphometric approach towards Halimeda taxonomy

Abstract

Traditional taxonomy of the segmented green algal genus Halimeda is largely based on descriptive expressions of thallus habit, segment shape and anatomical structures. In the course of the last decade, molecular phylogenetic studies have revealed non-monophyly and cryptic diversity in several species. In an attempt to tackle the taxonomic problems that were raised by these molecular studies, a combined molecular and morphometric method was developed. In this study, a morphometric pilot data set is explored. This resulted in the discovery of segments aberrant in morphology and/or anatomy. These are primarily apical and non-calcified segments, and segments from the basal part of the algal body..