Cyber catalogue and revision of the nematode genus Enchodelus 

All available information on Enchodelus species is brought together. This will contribute to a more complete assessment of species diversity and distribution.

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Guest blog post by Milka Elshishka and Vlada Peneva

The order Dorylaimida is the most diverse nematode group, with over 2640 valid species and more than 260 valid genera, with new taxa being described each year. They are the richest nematode order in number of species in natural soils. Dorylaims are often regarded as good environmental bio-indicators since the number of species/specimens drastically decreases following any significant disturbance in their habitat.

In our study, published in the Biodiversity Data Journal, we examined one intriguing free-living dorylaimid nematode taxon: the genus Enchodelus which is considered to have conservation value. The genus currently includes 28 species, which display a distinct distributional pattern, being spread mainly in high altitudinal enclaves of the Northern Hemisphere (with the exception of E. brasiliensis, only known to occur in Brazil). Its representatives are often associated with mosses and cliff vegetation. Although their feeding habits have not been studied with experimental protocols, it is traditionally assumed that they are omnivorous.

Distribution of Enchodelus species

The genus Enchodelus has not been recently revised; the descriptions of many ‘old species’ (that have been described long ago and have not been reported since their original discovery) are of poor quality, hardly discoverable, and do not conform to today’s taxonomical standards.

An Enchodelus species.

Actually, information available from databases often is limited to some of the species and usually incomplete as relevant data are missing. Consequently, a comprehensive compilation and analysis of literature data is indispensable to reach new insights into the taxonomy of the genus and to elucidate its evolutionary relationships.

Our work provides a cyber catalogue of Enchodelus species, where all available data for the species are accessible and collected in one place, which will greatly facilitate future research. It compiles available information from key European Research Infrastructures, such as TreatmentBank, the Swiss Institute of Bioinformatics Literature Services (SIBiLS), the Catalogue of Life (CoL), the Global Biodiversity Information Facility (GBIF), the European Nucleotide Archive (ENA) and the Biodiversity Literature Repository (BLR). Data about their distribution (geographical records and habitats) are incorporated too and all brought together. It is completed with discussion and notes for some species, along with information on species distributions and microhabitats.

Here, all available information on Enchodelus species is brought together. This will contribute to a more complete assessment of species diversity and distribution and support further biogeographical and ecological research.

The type species Enchodelus macrodorus is the most widely spread and reported Enchodelus species. It is a typical member of Palearctic nematode fauna, recorded in a myriad of countries and habitats and very sporadically recorded in Nearctic and Indomalayan enclaves. In our study we add new morphological and molecular data for this species collected from Spain.

Enchodelus macrodorus from Spain.

Additionally, type material of Enchodelus vestibulifer, belonging to Edmond Altherr’s collection, deposited at the Museo Cantonale di Storia Naturale di Lugano (Switzerland), is re-examined.

This species was described by the Swiss nematologist Edmond Altherr in 1952 on the basis of a single female from Switzerland and no later record of it exists. The re-examination of this material revealed that several relevant traits are not compatible with those characterising the genus Enchodelus and we considered it as incertae sedis.

In our study we also present one new species, Enchodelus enguriensis. It was collected from moss on stone (Tortellasquarrosa) in Caucasus, Georgia (Samegrelo-Zemo Svaneti Region, Bogreshi, Enguri River, Tower of Love). The description of the new species was supported by a comprehensive phylogenetic analysis based on D2-D3 of 28S rRNA. When naming the new taxon, we selected the name of the place from which the material was collected, namely the River Enguri; it was recovered from the stone next to the Tower of Love on the bank of the river.

We are grateful for the support the BiCIKL project, Grant No 101007492.

Research article:

Elshishka M, Mladenov A, Altash S, Álvarez-Ortega S, Peña-Santiago R, Peneva V (2024) Cyber catalogue and revision of the nematode genus Enchodelus (Dorylaimida, Nordiidae). Biodiversity Data Journal 12: e126315. https://doi.org/10.3897/BDJ.12.e126315