Four new enchytraeid species (Enchytraeidae, Annelida) from a Korean mountain (Jeoksangsan).

In this article, the descriptions of four new enchytraeid species (Enchytraeidae, Clitellata) from Jeoksangsan (Deogyusan National Park, Korea) are presented: Decimodrilus bulbosus sp. n., Fridericia jeoksangsaniensis sp. n., Fridericia sphaericoides sp. n. and Mesenchytraeus globiferus sp. n. Validity of these new species was verified by comparative morphological and molecular taxonomic analyses (based on the ITS region, CO1 and H3 genes). Apart from the new species, 13 other enchytraeid species were recorded in the soil samples of Jeoksangsan. In addition, new reference sequences are provided for the previously described Fridericia seoraksani Christensen Dzsa-Farkas, 2012.

Anion-type modulates the effect of salt stress on saline lake bacteria.

Beside sodium chloride, inland saline aquatic systems often contain other anions than chloride such as hydrogen carbonate and sulfate. Our understanding of the biological effects of salt composition diversity is limited; therefore, the aim of this study was to examine the effect of different anions on the growth of halophilic bacteria. Accordingly, the salt composition and concentration preference of 172 strains isolated from saline and soda lakes that differed in ionic composition was tested using media containing either carbonate, chloride or sulfate as anion in concentration values ranging from 0 to 0.40 mol/L. Differences in salt-type preference among bacterial strains were observed in relationship to the salt composition of the natural habitat they were isolated from indicating specific salt-type adaptation. Sodium carbonate represented the strongest selective force, while majority of strains was well-adapted to growth even at high concentrations of sodium sulfate. Salt preference was to some extent associated with taxonomy, although variations even within the same bacterial species were also identified. Our results suggest that the extent of the effect of dissolved salts in saline lakes is not limited to their concentration but the type of anion also substantially impacts the growth and survival of individual microorganisms.

Three new enchytraeid species (Enchytraeidae, Annelida) from mountain soils of Korea and ten species new for the country.

In this paper, three new enchytraeid species (Enchytraeidae, Clitellata) are described from different mountains of Korea: Cognettia koreana sp. n., Henlea bidiverticulata sp. n. and Mesenchytraeus longidiverticulatus sp. n. Validity of these new species was confirmed by comparative morphological and molecular taxonomic analyses (based on ITS, CO1 and H3 sequences). In addition, ten enchytraeid species never recorded before from Korea were found in the studied soil samples: Bryodrilus diverticulatus Cernosvitov, 1929, Cernosvitoviella atrata Bretscher, 1903, Cernosvitoviella minor Dózsa-Farkas, 1990, Cognettia lapponica Nurminen, 1965, Cognettia varisetosa (Martinsson, Rota Erséus, 2015), Fridericia cf. sohlenii Rota, Healy Erséus, 1998, Henlea nasuta Eisen, 1878, Marionina clavata Nielsen Christensen, 1961, Marionina communis Nielsen Christensen, 1959, Marionina seminuda Xie Rota, 2001. Morphological observations and new reference DNA sequences are also provided for the above-mentioned species.

Decimodrilus, a new enchytraeid genus from Korea (Annelida, Clitellata, Enchytraeidae).

Two new species of the new genus Decimodrilus gen. n. are described in this paper from oak forests of South Korea using a combination of classical morphology and DNA-based molecular taxonomy. A characteristic trait of the new genus is the occurrence of the intestinal diverticula in segments IX-X. The main morphological features of the new genus are: 4-5(6) straight chaetae per bundle, origin of dorsal vessel in clitellar region, anteseptale of nephridia consisting of funnel only, coelomocytes only mucocytes, oesophageal appendages absent, spermathecae united proximally and connected jointly with the oesophagus. Decimodrilus diverticulatus sp. n. has spermathecae with two diverticula-like protrusions and two globular sperm masses. D. globulatus sp. n. has spermathecae with two or three sperm rolls. Molecular taxonomic analysis based on a concatenated phylogenetic tree supports the status of the new genus and that of the two new species.

Two new enchytraeid species from Jeju Island, Korea (Annelida, Clitellata).

The enchytraeid fauna of three areas in Jeju Island (Korea) was studied, and comparative morphological and molecular taxonomic examinations (based on CO1, ITS and H3 sequences) were performed on nine samples collected in 2016. Twenty-two enchytraeid species were recorded and identified. The descriptions of two new species (Achaetamultisacculata sp. n. and Fridericiafloriformis sp. n.) are presented in this paper. The main diagnostic features of A.multisacculata sp. n. are: three pairs of pyriform glands per segment, clitellum with two "baguette-like" packages of glands, dorsal blood vessel from VII, secondary pharyngeal glands absent, oesophageal appendages well developed, two pairs of preclitellar nephridia, the reproductive organs (except the spermathecae in V) shifted one segment forward. The main features of F.floriformis sp. n. are that they are large worms, have up to 2-4 chaetae in bundles, strong body wall, thick cuticle, five pairs of preclitellar nephridia, c-type coelomo-mucocytes sometimes with some refractile vesicles, chylus cells in XII-XV, sperm funnels approximately twice as long than wide, spermathecae with long ectal duct without glands, ampullae surrounded distally by about 9-12 sessile diverticula of varying size. Molecular phylogenetic analyses supported the morphological results and confirmed the status of the two new species.

Morphological and molecular distinction of two Fridericia species (Clitellata, Enchytraeidae) having same spermatheca type.

One enchytraeid species, proved to be new to science, is described in this paper as Fridericia ventrochaetosa sp. nov. The new species is distinguished from similar species, especially from F. galba (Hoffmeister, 1843), which has almost the same type of spermatheca, on the basis of morphological characters and molecular data (nuclear ribosomal ITS region, mitochondrial cytochrome c oxidase subunit I and nuclear histone 3 gene sequences). Apart form the new species, GenBank reference sequences are provided for the first time for F. hegemon and F. regularis. The results show that, although the shape of the spermatheca is a very important marker in the case of Fridericia species, other characters can be equally important for their taxonomic identification.

New enchytraeid species from Mount Hallasan (Jeju Island, Korea) (Enchytraeidae, Oligochaeta).

The enchytraeid fauna of Mt. Hallasan (Jeju Island, Korea) was studied in 2016, and 21 enchytraeid species were recorded and identified in total. A combination of morphological and molecular analyses (based on CO1, ITS and H3 sequences) was applied. Here we give descriptions of eight new species of Enchytraeidae (Clitellata): Achaeta koreana sp. n., Achaeta macroampullacea sp. n., Bryodrilus hallasanensis sp. n., Chamaedrilus baekrokdamensis sp. n., Enchytronia seongpanakiensis sp. n., Mesenchytraeus jungsaihoi sp. n., Xetadrilus jejuensis sp. n. and Xetadrilus aphanoides sp. n. Additionally, two species were found to be new for the Korean fauna in Mt. Hallasan: Fridericia cf. paroniana Issel, 1904 and F. perrieri (Vejdovský, 1878); three potentially new Fridericia species require further studies. Furthermore, two terrestrial polychaetes, Hrabeiella periglandulata Pizl Chalupský, 1984 and Parergodrilus heideri Resisinger, 1925, were recorded. For 12 enchytraeid species, DNA sequences are presented for the first time: these include, apart from the new species, further taxa such as species of Xetadrilus, a genus of which no sequences were previously available.