Molecular phylogenetic and morphological analyses of prostrate Codium (Chlorophyta) in Japan

The morphology of utricles was critically studied in order to elucidate the species composition of prostrate Codium in Japan. Utricle morphology, such as length, diameter, shape of apical portions, presence or absence of hairs (or hair-scars) and alveolate ornamentation, are shown to characterize the clades recognized in our previous molecular analysis. These molecular and morphological congruences indicate that these morphological features reflect the phylogeny of Codium. The prostrate Codium in Japan was classified into the following five species: C. arabicum Kützing, C. capitulatum Silva & Womersley, C. dimorphum Svedelius, C. hubbsii Dawson, C. lucasii Setchell.