Myung Sook Kim

Reinstatement of Gracilariopsis chorda (Gracilariaceae, Rhodophyta) Based on Plastid rbcL nad Mitochondrial cox1 Sequences

Two different molecular markers, the plastid rbcL and mitochondrial cox1 genes, were used to define the taxonomic position of the northwest Pacific Ocean species currently named Gracilaria chorda. We analyzed both genes (1,222 bp for rbcL and 1,245 bp for cox1) from 18 specimens collected in Korea, Japan, and China. Phylogenetic reconstruction revealed that this organism should be classified in the genus Gracilariopsis, rather than in the Gracilaria. Thus, Gracilariopsis chorda (Holmes) Ohmi is the legitimate name for Gracilaria chorda Holmes. Within the species, the sequences differed by 8 bp (0.7%) in rbcL and 5 bp (0.4%) in cox1. Six haplotypes of cox1 tended to be geographically organized. Gp. chorda is characterized by coarse, elongate terete axes, short filiform branchlets usually at irregular intervals, an abrupt transition in cell size from medulla to cortex, cystocarps without tubular nutritive cells connecting the gonimoblast to the upper pericarp, and relatively large gonimoblast cells of the cystocarp in the specimens collected from Wando in southern Korea.

Species Composition and Biomass of Intertidal Seaweeds in Chuja Island

The marine benthic algal flora and biomass of Chuja Island, southern coast of Korea, was investigated. The collections of intertidal marine algae were made at two sites, Yecho of Hachujado and Hupo of Sangchujado, from October 2006 to July 2007. A total of 162 species, including 15 green, 47 brown and 100 red algae, were identified in this study. The occurrence of species according to season was abundant during spring to summer and less in autumn. The vertical distribution of intertidal zone in Chujado was characterized by Gloiopeltis spp., Myelophycus simplex, Ishige okamurae, Chondrus ocellatus, Grateloupia elliptica, Hizikia fusiformis and Sargassum spp. The average biomass of macroalgae was measured as 400 g wet wt m. The dominant species based on the biomass were Sargassum yezoense, S. coreanum and Hizikia fusiformis. ESG II (ecological state group) as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, occurred 85.8% in the intertidal seaweeds. These results provide a baseline for future monitoring studies in the Chuja Island.

Taxonomy and Phylogeny of Neosiphonia japonica (Rhodomelaceae,Rhodophyta) Based on rbcL and cpeA/B Gene Sequences

Neosiphonia M.S. Kim et I.K. Lee is a rhodomelacean red algal genus that is commonly encountered in the intertidal zone of temperate waters in the world. The genus Neosiphonia, which was established based on species previously named under the genus Polysiphonia, is well distinguished by procarps bearing a three-celled carpogonial branches, spermatangial branches arising from a branch of the trichoblasts, and tetrasporangia arranged in spiral series (Kim and Lee 1999). The phylogenetic difference of Neosiphonia from Polysiphonia is clearly shown by both cladistic analyses of morphological features and phylogenetic analyses of nuclear ribosomal small subunit (SSU) region sequences (Choi et al. 2001). Recently, Neosiphonia is found in Malaysia (Masuda et al. 2001; Tani et al. 2003), Vietnam (Abbott et al. 2002), Brazil (Guimaraes et al. 2004), Hawaii (Kim and Abbott 2006), and Japan as well as Korea (Kim 2005). To date, 22 species previously placed in Polysiphonia have been transferred into Neosiphonia and 1 new species reported. Neosiphonia japonica (Harvey) M.S. Kim et I.K. Lee was originally described from Hakodate, Hokkaido, Japan, as Polysiphonia japonica by Harvey (1856). The species has a bush-like habit, four pericental cells, cortication on axes, numerous branches, and three-celled carpogonial branches on females. The thalli occur commonly as epiphytes on other seaweeds from Korea (Kim 1995), Japan (Yoshida 1998), China (Tseng 1984), and Pacific Russia (Perestenko 1994). Despite studies on the morphology (Yoon 1986; Kudo and Masuda 1986; Kim 1995), life history (Kudo and Masuda 1986), lectotypification (Masuda et al. 1995), and distribution (Kim 1995), the taxonomy of N. japonica is still problematic. Kudo and Masuda (1986) reported that N. japonica (as Polysiphonia japonica) is very similar to N. harlandii (Harvey) M.S. Kim et I.K. Lee, N. decumbens (Segi) M.S. Kim et I.K. Lee, and P. akkeshiensis Segi. Yoon (1986) also concluded N. savatieri (Hariot) M.S. Kim et I.K. Lee, P. forfex Harvey and N. teradomariensis (Noda) M.S. Kim et I.K. Lee as varieties of N. japonica, based on the number of pericentral cells and the presence or absence of cortication at the base. Recently, McIvor et al. (2001) proposed that N. japonica, together with P. akkeshiensis Segi, P. acuminata N.L. Gardner and P. strictissima J.D. Hooker & Harvey were conspecific with N. harveyi (J. Bailey) M.S. Kim, H.G. Choi, Guiry & Algae Volume 21(3): 287-294, 2006

Taxonomic Note of Polysiphonia pacifica (Ceramiales, Rhodophyta) Complex with Focus on Pacific Isolates

Polysiphonia pacifica is rhodomelaceous red algal species that includes five varieties in Pacific Ocean: P. pacifica var. delicatula, P. pacifica var. distans, P. pacifica var. determinata, P. pacifica var. disticha, and P. pacifica var. gracilis. We here report morphology and phylogeny of P. pacifica to confirm the relationships among previously described varieties as a loan of type specimens from US and to assess phylogenetic relationships of closely related species using plastid protein-coding rbcL gene. Polysiphonia pacifica is distinguished by having creeping filaments attached by unicellular rhizoids not cut off by cross walls, four pericentral cells, ecorticate, trichoblasts rare, ultimate branchlets attenuate at the tip but not pungent, and tetrasporangia in long straight series in the ultimate branchlets. The protein-coding plastid rbcL gene sequence data show that P. pacifica is distinctly different from the superficially similar species, P. morrowii and P. stricta. However, the rbcL sequences of P. pacifica var. pacifica and var. disticha are identical though they have morphological variation.

Neosiphonia yongpilii sp. nov. (Rhodomelaceae, Rhodophyta), known as Neosiphonia simplex from Korea, with an emphasis on cystocarp development

Abstract: A critical re-examination of recent collections and herbarium specimens from Korea previously referred to Neosiphonia simplex (Hollenberg) Y.Lee showed them to be incorrectly identified. The phylogenetic analyses of rbcL sequences demonstrated that ‘N. simplex’ from Korea formed a clade distinct from other species in Polysiphonia sensu lato, and was clearly separate from N. simplex from California, with high sequence divergence. We propose N. simplex sensu Y.Lee from Korea as the new species, Neosiphonia yongpilii sp. nov. This novel species was characterized by severely twisted erect axes, with two to three pinkish sterile cells at apices of spermatangial branches. We also noted that lateral and basal sterile cell groups remain until maturation of the gonimoblast, and that the origin of inner and outer cortical filaments of the pericarp are central cells and pericentral cells respectively.

Sequence repeats enlarge the internal transcribed spacer 1 region of the brown alga Colpomenia sinuosa (Scytosiphonaceae, Phaeophyceae)

Colpomenia sinuosa is an annual brown algal species that occurs in temperate to tropical waters of the world. In order to examine the genetic diversity among populations of the species and to discuss its current distribution, we analyzed the nuclear ribosomal DNA internal transcribed spacer (ITS) region from 18 specimens of C. sinuosa, and, for comparison, plastid rbcL from the same specimens. The C. sinuosa ITS region (2141–2534 base pairs) is approximately 2.2 times the length of most other brown algae. We found a long repeated sequence of approximately 190 base pairs in the first half of the ITS1 region; five repeats in Northern Hemisphere collections and three in those from the Southern Hemisphere, which result in ITS length variation. The unequal occurrence of tandem repeats of C. sinuosa corresponds to the geographical distribution of the species. The rbcL sequences from all the specimens of C. sinuosa, except the Canary Island samples, were identical, indicating that they indeed belong to the same species.