We give descriptions of five new enchytraeid species (Enchytraeidae, Oligochaeta) from Korea: Henlea magnaampullacea sp. n., Fridericia sphaerica sp. n., F. cusanicaformis sp. n., F. granulocyta sp. n. and Mesenchytraeus calyx sp. n., with morphological and molecular (mitochondrial cytochrome c oxidase subunit I, nuclear histone 3 genes and nuclear ribosomal ITS region sequences) data. In total, 19 enchytraeid species belonging to seven genera have been found in the studied woodland and agronomical soil samples. Apart from the five new species, three further species are new for the Korean enchytraeid fauna, Enchytraeus christenseni, E. dichaetus, and Achaeta cf. brevivasa. Molecular taxonomical analyses show that the Korean species resembling H. ventriculosa is not identical with the European species, furthermore sequence analysis of individuals morphologically identified as F. seoraksani indicate the possibility of species-complexity and the presence of cryptic species.

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 Pižl & 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.

Annelids (Lumbricidae and Enchytraeidae) and nematodes are common soil organisms and play important roles in organic matter decomposition, nutrient cycling and creation of soil structure and porosity. However, these three groups have rarely been studied together and only few studies exist for urban soils. We studied the diversity and community composition of annelids and nematodes in soils spanning more than two centuries of urban soil development in Neuchâtel (Switzerland) and assessed the relationships 1) among these three groups and 2) between each group and environmental (physical, chemical and functional) characteristics of soils and soil age. While the groups of environmental variables were correlated (Mantel tests) no correlation was found between pairs of soil fauna groups and between each soil fauna group and environmental variables. More specifically, redundancy analyses showed that earthworm assemblages were best correlated with soil bulk density and with soil depth, the latter being positively correlated with soil age. Enchytraeid assemblages and the proportion of enchytraeid r-strategists were respectively best correlated with soil carbonate content and negatively correlated with soil age. Nematodes assemblages were best correlated with soil water content. Moreover, relationships between pairs of soil biota groups, and between each group and environmental (physical, chemical and functional) variables, varied along the soil age gradient (moving window analysis). This study provides new knowledge on urban soil biodiversity and how environmental conditions can influence soil diversity and community patterns in the urban context. The contrasted community patterns of earthworms, enchytraeids and nematodes in urban soils of different ages and their different ecological roles suggest that they represent potential complementary indicators of soil quality and functioning such as soil formation and organic matter dynamics.

This is the first occasion that the enchytraeid (Enchytraeidae, Oligochaeta) fauna has been investigated in Korea. 18 enchytraeid taxa (7 genera) and two terrestrial polychaetes (Hrabeiella sp. and Parergodrilus heideri) were identified. Three species are new to science (Hemienchytraeus koreanus sp. n., H. jeonjuensis sp. n. and H. quadratus sp. n.); they are described here. Twelve taxa were distinguished at species level, four of them are cosmopolitan widespread species in the Holarctic, and one, Enchytraeus irregularis is obviously an introduced species. The two polychaetes were known previously only from Europe.

No abstract