Eun Chan Yang

Recent introduction of Polysiphonia morrowii (Ceramiales, Rhodophyta) to Punta Arenas, Chile

Abstract Polysiphonia morrowii (Rhodomelaceae, Rhodophyta) is abundant in intertidal zones of the northwestern Pacific Ocean in spring, and has been introduced to the Mediterranean Sea. We collected specimens of this species from intertidal rocks in February in Punta Arenas, in southernmost Chile. Thalli were densely tufted, slender, and elongate, with four pericentral cells, no cortication and short tetrasporangial ultimate branchlets. The plastid protein-coding rbcL was analyzed from specimens collected in Chile and Korea, as well as from putative relatives. The rbcL sequences of the Chilean specimens were almost identical to those from Korea, and were clearly separated from other related taxa from Chile and other areas. These results suggest that P. morrowii has been introduced recently from the northwestern Pacific Ocean to Chile.

Taxonomy and phylogeny of flattened species of Gracilaria (Gracilariceae, Rhodophyta) from Korea based on morphology and protein-coding plastid rbcL and psbA sequences

M.-S. Kim, E.C. Yang and S.M. Boo. 2006. Taxonomy and phylogeny of flattened species of Gracilaria (Gracilariceae, Rhodophyta) from Korea based on morphology and protein-coding plastid rbcL and psbA sequences. Phycologia 45: 520–528. DOI: 10.2216/05-38.1 Despite extensive studies on cylindrical Gracilaria species, the taxonomy and phylogeny of the flattened species of the genus has received little attention. We studied the morphology and molecular phylogeny of three flattened species of Gracilaria, hitherto reported from Korea. Gracilaria textorii is characterized by having a wider blade relative to other species, margins entire or proliferous, coriaceous thallus texture, one to three large cells in the medulla, and shallow male conceptacles. Gracilaria cuneifolia is membranous in texture, and has shallow spermatangial conceptacles (approximately 10 µm in depth). We generated psbA and rbcL sequences from 32 specimens of G. textorii, G. cuneifolia and its putative relatives in Korea and surrounding waters. Twenty-three specimens of G. textorii from Korea, including two from Japan, were almost identical in both rbcL and psbA regions, except for some specimens that were different by one to four nucleotides. Three specimens of G. cuneifolia were identical in both rbcL and psbA. However, we found no evidence for the occurrence of G. incurvata in Korea. In all analyses of rbcL, psbA, and rbcL + psbA data sets, G. textorii was determined to be a unique species, with G. incurvata from Japan as a sister species. Gracilaria cuneifolia is more closely related to the G. tikvahiae group from the Atlantic than G. textorii and G. incurvata.

Morphology, basiphyte range, and plastid DNA phylogeny of Campylaephora borealis stat. nov. (Ceramiaceae, Rhodophyta)

blue.weeg.uiowa.edu The ceramiaceous red algal genus Campylaephora J. Agardh includes three species that occur exclusively in the northwest Pacific Ocean. We studied the morphology, basiphyte range, and molecular phylogeny of Campylaephora borealis, considered a variety of the C. crassa complex, using material collected over its geographic range. Samples of C. borealis, C. crassa, C. hypnaeoids, and putative relatives were taken from 43 locations in Korea, Japan, and Far-East Russia, including the type localities of the first two of these species. Campylaephora borealis is distinguished by proliferous branchlets on all sides of the main branches and an alternate branching pattern. It is characteristically epiphytic on diverse plants, such as Prionitis divaricata, and occurs mostly in exposed sites. It is distributed from Maengbang, Korea to Nakhodka, Far-East Russia. Based on pairwise divergences of the plastid RuBisCo spacer region and psbA sequences, C. borealis is more closely related to C. hypnaeoides than to C. crassa. The topology of the tree constructed using the combined data shows the monophyly of C. borealis, which is clearly separated from other Campylaephora species and putative relatives. Our molecular data together with the basiphyte range and a morphological reappraisal point to the independent taxonomic position of C. borealis, isolated from Campylaephora crassa. Therefore, we propose to raise Campylaephora crassa f. borealis to the rank of species: Campylaephora borealis (Nakamura) Seo et al., stat. nov. The phylogeny of Campylaephora is also discussed.

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.

Cyanidiophyceae in Iceland: plastid rbcL gene elucidates origin and dispersal of extremophilic Galdieria sulphuraria and G. maxima (Galdieriaceae, Rhodophyta)

Abstract: The Cyanidiophyceae are a group of unicellular organisms that diverged from ancestral red algae around 1.3 billion years ago. Present-day species are restricted to hot springs and geothermal habitats from around the world. Because of discontinuous geothermal environments, the distribution patterns and dispersal modes of the cyanidiophycean species are poorly understood. Iceland is the third largest island in the Atlantic Ocean and has intense underground volcanic activity that generates broad hydrothermal areas with different ecological conditions that are excellent for thermoacidophilic microfloral development. We analyzed populations to address the Icelandic cyanidiophycean biodiversity and dispersal. A global rbcL phylogeny showed two main populations inhabiting Iceland, Galdieria sulphuraria and G. maxima. Their areas of distribution are not completely superimposed because they coexisted only in New Zealand, Kamchatka (Russia), Japan, and Iceland. Because of the strong monophyly of Icelandic species with Japanese and Russian species, we hypothesized an origin and dispersion of Icelandic G. suphuraria and G. maxima from northeastern Asia. On the basis of network analysis of rbcL haplotypes, it is likely that the southwestern region of Iceland is the diversity center of both G. sulphuraria and G. maxima.

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.

RuBisCO cistron sequence variation and phylogeography of Ceramium kondoi (Ceramiaceae, Rhodophyta)

Ceramium kondoi is a morphologically variable ceramiaceous red alga that occurs commonly in the northwest Pacific Ocean region and has recently been reported in the United States. Forty-five specimens of C. kondoi from 29 locations in Korea, Japan, Russia, and the USA were examined for DNA sequence variation along the whole plastid-encoded RuBisCO cistron: 1406 bp for rbcL, 103 bp for the spacer, and 387 bp for rbcS. C. kondoi specimens were variable, having up to nine haplotypes, with six found in Korea, southern Japan, far-eastern Russia, and the USA, and three found in northern Japan and far-eastern Russia. The occurrence of the same haplotype on both sides of the North Pacific Ocean provides evidence of recent introduction of the species from the west to the east. Phylogenetic reconstructions revealed the monophyly of C. kondoi and two well-supported lineages: a ‘southern lineage’ that contained specimens from Korea, southern Japan, far-eastern Russia and the USA, and a ‘northern lineage’ that included specimens from northern Japan and far-eastern Russia. The two genetic lineages are morphologically indistinguishable and referred to as cryptic species. The boundary between the two cryptic species is at the Tsugaru Strait, Japan.

The Occurrence of Griffithsia okiensis (Ceramiaceae, Rhodophyta) from Korea on the Basis of Morphology and Molecular Data

Despite continued studies on red algal flora in Korea, the taxonomy of the tiny ceramiaceous algae has received little attention. We report for the first time Griffithsia okiensis from Korea on the basis of morphology and molecular data. The species is small in thalli height (0.3-1.5 cm), and in diameter of vegetative cells (50-500 μm), and the ratio of cell length/breadth is 2-3 times. It has two carpogonial branches from the supporting cell of procarp. We generated psbA and rbcL sequences from ten specimens of G. okiensis isolated from Korea and Japan and from one G. japonica species isolated Japan. Eight specimens of G. okiensis from Korea were almost identical in both psbA and rbcL regions, nevertheless they differed from Japanese specimens by 4 ucleotides in psbA and 7 in rbcL. In all analyses of psbA, rbcL, and psbA + rbcL data sets, G. okiensis was determined to be a different species from G. japonica isolated from Japan, although both species showed a sister relationship. For all that extensive collection trips, we found no evidence for the occurrence of G. japonica in Korea.