부산대학교 도서관

A green alga specimen was collected from the eastern coast of Korea. This species shared the typical features of genus Ulva and was characterized by irregularly shaped thalli, relatively small and thick thallus, entire undulate margins without serrations , and one or two pyrenoids per cell. In a phylogenetic tree, based on sequences of the nuclear-encoded internal transcribed spacer region, it nests as a sister clade to a few species including Ulva ohnoi, which has a relatively large thallus. This Korean algal specimen differs from the species forming the same subclades, including U. ohnoi, Ulva fasciata, Ulva reticulata, and Ulva gigantean, and has a relatively small (3–8 cm) and thick (60–100 μm) thallus. Of these species, U. ohnoi, originally described from Japan, is similar to the Korean alga as it had a thick thallus of 30–90 μm, but it has microscopic serrations on the thallus margin, unlike the Korean alga. The genetic distance between the Korean alga species and the aforementioned species was determined to be 1.8%–4.8%, indicating an inter-specific divergence level at the genus Ulva. Herein, Ulva grossa sp. nov. (Ulvales, Chlorophyta) from Korea is described based on the morphological and molecular analyses.