Klára Dózsa-Farkas

Invasion of terrestrial enchytraeids into two postglacial tundras: North-eastern Greenland and the Arctic Archipelago of Canada (Enchytraeidae, Oligochaeta)

The aim was to study the invasion of terrestrial enchytraeids into the two postglacial tundras, North-eastern Greenland and the Arctic Archipelago of Canada. The majority of species recorded have a wide distribution in the Northern Hemisphere and the species diversity is considerably lower than that of potential source regions indicating either strong selection or varied dispersal ability. It appears that the Archipelago is influenced mainly from North America and North-eastern Greenland from Europe while the specialized fauna of the ancient Beringian tundra is of minor importance. The two alternative scenarios: (a) survival of a prepleistocene fauna in protected refugia within the area or (b) a postglacial re-invasion from outside are discussed, but the available data do not discriminate between these two possibilities. A total of 24 terrestrial enchytraeid taxa are recorded of which 22 are identified to the species level. Bryodrilus archipelagicus and Hemifridericia bivesiculata are described as new to science and Henlea groenlandica Černosvitov is revalidated. We hesitate to conclude that the new taxa described are endemic.

Christensenia, a new terrestrial enchytraeid genus from Antarctica

Christensenia gen. nov., C. blocki sp. nov., is described from Signy Island, South Orkney Islands, maritime Antarctic. The new species is identical with specimens that Stephenson (1932) determined as Marionina georgiana (Michaelsen, 1888), but differs from the type material of M. georgiana. The species M. georgiana (Michaelsen, 1888) is also placed in the new genus Christensenia, the main characteristics of which are: possession of sigmoid setae, and the presence of large numbers of small, hyaline, stick-like, anucleate lymphocytes. No other types of lymphocyte are observed. Oesophageal appendages and intestinal diverticulae are absent. Dorsal vessel originates in the clitellar region; blood is colourless. The anteseptal part of the nephridium consists of the funnel and a few canals, with the efferent duct arising postero-ventrally. Spermathecae are without diverticulae, entally connecting with the oesophagus. The known distribution of the genus is currently limited to terrestrial habitats in the sub- and maritime Antarctic.

A new genus Globulidrilus and three new enchytraeid species (Oligochaeta: Enchytraeidae) from Seoraksan National Park (Korea)

From the Seoraksan National Park, Korea, a new enchytraeid genus, Globulidrilus gen. nov., is defined and three new species, Globulidrilus helgei sp. nov., Fridericia seoraksani sp. nov. and Mesenchytraeus longiductus sp. nov., are described. Globulidrilus also includes Marionina riparia Bretscher, 1899 augm. Černosvitov 1928, a globally distributed species with a complicated taxonomic history. Pending a revision of Marionina riparia sensu latu (auct.), we retain the species name riparia for a variant of common occurrence in Europe.

Review of the Fridericia species (Oligochaeta: Enchytraeidae) possessing two spermathecal diverticula and description of a new species

A new Fridericia species (Fridericia lacii sp. nov.) is described. Including this new species the number of valid Fridericia species with two diverticula per spermatheca is 50. The present study provides an opportunity for the comparison and separation of Fridericia species on the basis of spermatheca and diverticulum characteristics. Nine tables summarize the two larger groups and five subgroups of species possessing bidiverticulate spermathecae. The new species is distinguished from all known valid congeners in this assemblage by the following combination of traits: (1) 4–7 mm long, 200–290 µm wide (in vivo) with 30–36 segments; (2) maximum four chaetae per bundle; (3) all pairs of pharyngeal glands with ventral lobes, the third is the largest with posterior projections; (4) only three pairs of preclitellar nephridia; (5) oesophageal appendages type a; (6) mucocytes type a, lenticytes small; (7) chylus cells in preclitellar segments; (8) clitellum girdle‐shaped, glands in transverse rows, between the bursal slits only granulocytes; bursal slit is longitudinal; (9) seminal vesicle small or absent; (10) sperm funnel one‐half as long as the body diameter, collar narrower than the funnel body; (11) subneural glands absent; (12) the ampulla of the spermatheca with two sessile (or with short stalks), spherical, thin‐walled diverticula, communication with the oesophagus separate, ectal duct about as long as body diameter, one floppy ectal gland at the orifice.

New enchytraeid species (Enchytraeidae, Oligochaeta) from Korea.

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.

Effect of human treading on enchytraeid fauna of hornbeam-oak forests in Hungary

SummaryThe effect of human treading on the composition of the enchytraeid fauna was studied on hiking trails in hornbeam-oak forests in Hungary. Compaction of the soil due to continuous treading has an unfavourable influence on the enchytraeid fauna, with density and species richness decreasing significantly. However, an interesting result is that one species, Fridericia conculcata, prefers these heavily trodden areas.

Placing the forgotten: on the positions of Euenchytraeus and Chamaedrilus in an updated enchytraeid phylogeny (Clitellata : Enchytraeidae)

Abstract. The phylogeny of Enchytraeidae was re-estimated to establish the relationships of the now resurrected Chamaedrilus and Euenchytraeus and to confirm their status as separate taxa. The former Cognettia (Enchytraeidae) was recently revised and split into its two senior synonyms, Chamaedrilus and Euenchytraeus, with the majority of the species transferred to Chamaedrilus. Euenchytraeus was re-established for three species sharing a unique anatomical trait, but has never before been represented in any phylogenetic study. We included representatives from 21 (of 33) valid enchytraeid genera and used three mitochondrial and four nuclear genes. The dataset (4164 base pairs) was analysed using multi-species coalescent (MSC) and maximum likelihood (ML) methods. Chamaedrilus (represented by eight species) and Euenchytraeus (represented by Eu. clarae) were found in a clade together with the monotypic Stercutus. Chamaedrilus was found to be monophyletic with maximum support in both analyses. The ML tree supported Euenchytraeus and Chamaedrilus as sister groups, whereas the MSC tree placed Euenchytraeus together with Stercutus, both with low support. A Bayes factor test weakly supported Euenchytraeus and Chamaedrilus as sister groups over Euenchytraeus + Stercutus. Possible morphological synapomorphies for these genera are discussed, and we conclude that Chamaedrilus and Euenchytraeus are closely related, but their status as separate genera is justified.

Extension of employing ITS region in the investigation of Hungarian Fridericia species

Abstract Same species of genus Fridericia (Oligochaeta: Enchytraeidae) collected from different localities, can have small differences in their morphology, for example, the number of nephridia or length and width of the spermathecal ectal duct. During the identification of enchytraeid worms, several characteristics were investigated at the same time but presence of small variations in only one or two main characteristics can cause taxonomic difficulties or may raise the possibility of encountering a subspecies. Using molecular biological techniques can help answer these questions. In preceding researches of the authors ITS (Internal Transcribed Spacer) came into focus. ITS is mainly a non-coding region of ribosomal DNA located between the 18S and 28S rDNA genes. Based on these previous studies, in the present analysis, the authors extended their investigation to include examination of the morphology and genes of various Fridericia species from different parts of Hungary. Phylogenetic trees were also created by Maximum Parsimony (MP), Neighbor-Joining (NJ), and Bayesian analyses. In the present study, we established that molecular biological techniques are suitable to confirm that individuals from the same species (but collected from different places) have the same genetic profile, while very similar species can be shown to clearly segregate on the phylogenetic tree based on the divergence of certain external or internal characteristics. Even though partial sequences give us only rough information about the phylogenetic position of the species, our aim is to show how the ITS region is suitable to investigate closely related enchytraeid worms and to differentiate the morphologically similar species.

On the composition of the intestinal microbiota of Fridericia hegemon (Enchytraeidae)

Abstract A computer-aided numerical taxonomic analysis on selected representative bacterial and actinomycete strains isolated from fresh faecal pellets of Fridericia Hegemon (Enchytraeidae) revealed that pseudomonads, belonging to a particular variety of Pseudomonas aureofaciens , are the predominant gut colonizers of this worm. These, together with nocardioform actinomycetes, among them “Non Motile Oerskovia-like Organisms” (NMOs: Type-B), Micrococcus spp and undetermined Gram-positive, nonfermenting rods constitute the larger fraction of the intestinal microbial population. The faecal bacteria of F. hegemon are mostly Gram-negative, non-fermenting, developing well at 5°C but, apart from a few strains, not multiplying at 38°C, actively producing H 2 S, growing quickly at high pH values. chitinase-negative and phosphatase-positive organisms, which can grow on simple synthetic media.

New enchytraeid species (oligochaeta: Enchytraeidae) from the danube-dráva National Park

The enchytraeid fauna of the Drava Floodplain (Bukkhat Forest Reserve, alder swamp and meadows at Kisszentmarton, and Barcs Nature Conservation Area belonging to the Danube–Drava National Park, Hungary) was investigated for the first time. A total of 14 enchytraeid genera, including 49 species and two other annelid worms (Hrabeiella periglandulata and Rhyacodrilus falciformis) were identified. Four species: Fridericia connatiformis sp. n., F. phaeostriata sp. n., F. longiducta sp. n. and Cernosvitoviella buekkhati sp. n. are new to science and described in this paper.