E-ISSN : 2713-8615
Afrolaophonte koreana sp. nov. is described from the intertidal zone of two sandy beaches on the south coast of Korea. This is the first record of the genus Afrolaophonte Chappuis, 1960 in the Northern Pacific. The new species is most similar to A. aequatorialis Cottarelli and Mura, 1981, described from the Maldives and subsequently also found in Papua New Guinea, but could be distinguished by numerous characters, including the segmentation of the third leg endopod in male, armature formula of the second leg in both sexes, length of caudal rami in both sexes, and length of some setae on the fourth leg in female. Afrolaophonte ensiger Wells and Rao, 1987 from the Andaman and Nicobar Islands is established as a junior subjective synonym of A. aequatorialis. To test previous phylogenetic hypotheses based on intuitive methods, a parsimony based cladistic analysis of 13 valid congeners is performed using 15 morphological characters and one outgroup. Only one of three previously proposed species-groups is supported with a synapomorphy, while one was clearly based on symplesiomorphies. Our current knowledge of morphology in this genus is not sufficient for postulating interspecific phylogenies, which also renders previous zoogeographical hypotheses untestable.
A study on silica-scaled chrysophytes (Chrysophyceae and Synurophyceae) from Mt. Sinbul alpine wetland, South Korea was performed from January 2018 to March 2020 using scanning electron microscopy (SEM). We found a total of 19 taxa of silica-scaled chrysophytes; Mallomonas (13); Synura (3); Chromophysomonas (1); Chrysosphaerella (1); and Paraphysomonas (1), of which six taxa, including two new species (Mallomonas dimorphus sp. nov. and Mallomonas alpestris sp. nov.), were reported for the first time in Korea. All the species are illustrated with SEM micrographs and briefly described with regard to their taxonomy. Two new species were described based on the cell shape, size and ultrastructure of the scales and bristles. Mallomonas dimorphus sp. nov. belongs to the Sectio Heterospinae in that its scales have a flat dome, a reticulated secondary layer and needle shaped bristles. However, this species is distinguished from other taxa in the Sectio by two different patterns of shield ornamentation and a dome ornamentation. Mallomonas alpestris sp. nov. belongs to Series Torquatae (Sectio Torquatae) characterized elongated domed collar scales, domeless body scales and rear scales with a short spine. However, it is different from all other taxa in the Sectio Torquatae as well as Series Torquatae by shield ornamentation of the body and rear scales with evenly spaced transverse ribs and papillae.
The current surveys of Ulva in the subtidal area around Jeju Island give a chance to discover unrecorded green algal species of the Korean macroalgal flora. As a result of this investigation, we found Ulva adhaerens Matusmoto & Shimada, inhabiting the subtidal regions, up to 15 m deep, and conducted the DNA barcoding on plastid rbcL-3P and tufA regions with describing the morphological characteristics. Our specimens of U. adhaerens forms a monophyletic clade with the Japanese type specimen and U. piritoka Ngāti Kuri, Heesch & W.A. Nelson from New Zealand exhibiting each 0.3% sequence divergences, respectively, in the plastid rbcL-3P. The genetic variation of U. adhaerens clade is 1.0-3.9% in rbcL-3P and 4.8-9.8% in tufA to each Ulva species, including the generic type, U. lactuca Linneaus. The morphology of Korean U. adhaerens specimens is identical to the type specimens of U. adhaerens from Japan having the development of rhizoidal filaments from both of the cell layers of the distromatic blade and the extension of rhizoidal clumps with adhesive trait between blades by extended rhizoidal clumps at the basal blades. The thallus attachment to substrate is by numerous minute discoidal plates made up of rhizoids originating from the inner part of distromatic blades in basal. Although there are still some problems to resolve the relationship between U. adhaerens and U. piritoka in the rbcL dataset and the phylogenetic pattern of the Group II intron of rbcL, we propose the new record of U. adhaerens in Korean macroalgal flora based on the morphological characteristics of Korean specimens. Continued study of the genus Ulva by morphological and molecular assessment will delimit the species of Ulva, elucidate the relationships between them, and uncover the species diversity.
During a field survey of Korean marine ciliates, we collected Pleuronema marinum from a brackish water sample. It is characterized by the presence of a contractile vacuole in mid-body, rather than the subterminal/ terminal contractile vacuole as in other congeners. The cells were examined in vivo and based on protargol and ‘wet’ silver nitrate impregnation. In addition, the nuclear 18S rRNA gene was sequenced using a single cell. The Korean population morphologically and molecularly resembles a Chinese population of P. marinum. Historical review of the species concludes that 1) two or more species have been assigned into P. marinum, 2) the position of contractile vacuole (e.g., in mid-body) is a valid character state, and 3) P. marinum is probably a rare species. Here we provide a monographic treatment of P. marinum to clarify the issue and for further studies of relevant species. Considering there are about 40 nominal species and complex nomenclatural acts in the genus Pleuronema, further studies should provide descriptions based on protargol and ‘wet’ silver impregnation with marker gene(s).
Three oxytrichid ciliates, Oxytricha lithofera Foissner, 2016, Pleurotricha curdsi (Shi et al., 2002) Gupta et al., 2003 and Sterkiella tetracirrata Kumar et al., 2015, were isolated from soils and confirmed as new to South Korea. Oxytricha lithofera was identified based on lithosomes, cortical granules, 21-33 adoral zone membranelles, one left (14-21 cirri) and one right (15-18) marginal rows and 5 transverse cirri. Pleurotricha curdsi was identified based on the possession of 2 macronuclear nodules, 2-3 micronuclei, 46-53 adoral zone membranelles, 3 frontal cirri, 5 frontoventral cirri, 5-7 postoral ventral cirri, 2-3 right marginal rows and 5 transverse cirri. Sterkiella tetracirrata was identified with respect 4 macronuclear nodules, 3-6 micronuclei, 25-40 adoral zone membranelles, 3 frontal cirri, 3 postoral ventral cirri, 2 pretransverse cirri, one left (21-30 cirri) and one right (24-30) marginal row and 4 transverse cirri. On the basis of 18S rDNA sequence analyses, we describe the phylogenetic positions of the three species.
Five newly recorded species of cyanobacteria in Korea are Sphaerospermopsis reniformis (Aphanizomenona- ceae) from Chungju-si, Chungcheongbuk-do; Pelatocladus maniniholoensis (Hapalosiphonaceae) from Ulleung-gun, Gyeongsangbuk-do; Tolypothrix carrinoi (Tolypothrichaceae) and Myxacorys chilensis (Lepto- lyngbyaceae) from Suwon-si, Gyeonggi-do; and Tildeniella torsiva (Oculatellaceae) from Gunsan-si, Jeolla- buk-do. These species are morphologically similar to each of its corresponding type species, and clustered in the same clade with respective type species in the phylogeny using 16S rRNA. The similarity of 16S rRNA sequences was more than 98.5% with each of its respective type species.
As a subset study to discover indigenous prokaryotic species in Korea, we isolated 20 bacterial strains and assigned them to the phyla Actinobacteria, Bacteroidota, Firmicutes, and Proteobacteria. From the high 16S rRNA gene sequence similarity (≥ 98.7%) and formation of a robust phylogenetic clades, we determined that each strain belonged to independent, predefined bacterial species. There are no official reports of these 20 species in Korea; therefore, 7 strains of the Actinobacteria, 2 strain of the Bacteroidota, 3 strains of the Firmicutes, and 8 strains of the Firmicutes are described in Korea for the first time. Gram reaction, colony and cell morphology, basic biochemical characteristics, and isolation sources are also described in the species description section.
Four species of cyanobacteria that are unrecorded in Korea were isolated from freshwater and brackish water. These four species are Laspinema thermale of Laspinemaceae, Planktothricoides raciborskii and Planktothrix spiroides of Microcoleaceae, and Cephalothrix lacustris of Phormidiaceae, all belonging to the order Oscillatoriales. Laspinema thermale is morphologically characterized as apical cells that are longer than other cells. In this strain, the similarity of the 16S rRNA gene sequence with the previously reported L. thermale strains were 99.30-99.50%. Planktothricoides raciborskii, which is characterized by bluntly conical morphology of apical cells, showed 98.80-99.50% of similarity of the 16S rRNA gene sequence to the previously reported P. raciborskii strains. Planktothrix spiroides are characterized by floating due to gas vacuoles. In this strain, the similarity of the 16S rRNA gene sequence with the previously reported P. spiroides strains were 99.80-99.90%. Cephalothrix lacustris, characterized by having calyptra in apical cells, showed 99.80-99.90% similarity of the 16S rRNA gene sequence to previously reported C. lacustris strains. Also, these species were clustered in the same clade in phylogenetic analysis using 16S rRNA gene sequences with each corresponding species.
Mesorhabditis microbursaris (Steiner, 1926) Sudhaus, 2011, belonging to the family Mesorhabditidae (Rhabditomorpha), is newly reported from South Korea. During a survey of small streams, M. microbursaris was isolated from sedimentary soil samples. The genus Mesorhabditis Osche, 1952 nematodes are distributed all over the world and are mostly found from terrestrial habitats, however are sometimes found in freshwater. At present, 34 valid species have been recorded from Mesorhabditis; however, only three species have been reported from South Korea. Mesorhabditis microbursaris exhibits morphological characters of other congeneric species, including shorter distance between vulva and anus than the distance between anus and tail, rudimentary bursa with narrow velum and short genital papillae, shorter spicules than tail and conical tail. However, this species can be distinguished from other Mesorhabditis species by its morphometric characters and three pairs of bursal papillae. Details of the morphological characteristics and morphometrics of M. microbursaris are described and illustrated based on optical microscopy.
Through the ‘Discovery of Korean Indigenous Species’ project hosted by the National Institute of Biological Resources (NIBR), new or unrecorded species of various protozoans inhabiting the Korean Peninsula have been discovered. Samples were collected from marine, freshwater, and soil habitats in South Korea and all species were identified and reviewed by experts working on the respective taxonomic group. This study includes 17 unrecorded Korean protozoan species discovered through this project, which belong to four phyla: Amoebozoa Lühe, 1913, Cercozoa Cavalier-Smith, 1998, Euglenozoa Cavalier-Smith, 1981, and Ciliophora Doflein, 1901. Among them, three families (Rhogostomidae Dumack et al., 2017, Parauronematidae Small and Lynn, 1985, and Cyclidiidae Ehrenberg, 1838) and three genera (Rhogostoma Belar, 1921, Parauronema Thompson, 1967, and Cyclidium Müller, 1773) were reported for the first time in Korea. Unlike the previous paper of 2017, this study provides a comprehensive taxonomic account of each species (e.g., species name, collection site, synonyms, specimen vouchers, diagnoses, and figures). Additionally, all the species were assigned Korean names.
The classification system of Collybiopsis has been updated to contain some species of Collybiopsis, Gymnopus sect. Vestipedes, and Marasmiellus. Recently, we conducted the taxonomic study of Korean Collybiopsis to reflect the current classification system and confirmed 16 species. We propose their Korean names in this research note.