Population genetic structure in Sabatieria (Nematoda) reveals intermediary gene flow and admixture between distant cold seeps from the Mediterranean Sea

First molecular observation on Mylonchulus hawaiiensis from South Africa

During a survey of soil nematodes in South Africa, a species of predatory nematodes, namely Mylonchulus hawaiiensis was recovered from soil in the Magoebaskloof mountain of Limpopo Province, South Africa. The morphology of the material studied fit well with the previous populations of the same species. A molecular study of 18S rDNA region of M. hawaiiensis indicated a 100% similarity between the South African population and the Japanese population of M. hawaiiensis (AB361438; AB361439; AB361440; AB361442). In addition, phylogenetic analysis placed all M. hawaiiensis in a group with 0.97 posterior probability. Additionally, ITS rDNA of M. hawaiiensis amplified for the first time. However, Principal component analysis (PCA) showed a morphological variation among the different populations of M. hawaiiensis. In addition, haplotype analysis also revealed that the South African population is close to the Japanese population. In conclusion, 18S rDNA was a good marker for detecting M. hawaiiensis. Measurement, photographs, and phylogenetic position of South African M. hawaiinesis are given.

Phylum Nematoda: trends in species descriptions, the documentation of diversity, systematics, and the species concept

This paper summarizes the trends in nematode species description and systematics emerging from a comparison of the latest comprehensive classification and census of Phylum Nematoda (Hodda 2022a, b) with earlier classifications (listed in Hodda 2007).   It also offers some general observations on trends in nematode systematics emerging from the review of the voluminous literature used to produce the classification.   The trends in nematodes can be compared with developments in the systematics of other organisms to shed light on many of the general issues confronting systematists now and into the future.