Ulva partita sp. nov., a Novel Enteromorpha-Like Ulva Species from Japanese Coastal Areas

Abstract

In this report, Ulva partita Ichihara, sp. nov. (Ulvales, Ulvophyceae) was described from Japanese seashores. This species was characterized by (i) frequent branches in the basal region, but not in the middle to upper region, (ii) being up to 20 cm in height and 5 mm in diameter, and (iii) containing chloroplasts covering the outer cell wall in the middle and upper regions of thalli, but with many chloroplasts leaning to one side of the cells in the basal region. Ulva partita is distinguished from morphologically similar species based on the branching pattern, early development pattern, and gamete size. Molecular phylogenetic analyses of nuclear-encoded ITS2 sequence and chloroplast-encoded rbcL sequences also strongly supported the independence of this species.