<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The identity of <italic>Panagrellus pycnus</italic>, the type species of the genus <italic>Panagrellus</italic>, is discussed after studying specimens from a cultured population collected in Italy that fits the original material of the species. A new characterization is consequently provided as follows: body 0.93–1.32 mm long, lip region continuous with the adjoining body, stoma with gymnostom very reduced, pharynx with not swollen metacorpus, neck 161–203 µm long, excretory pore at level of the metacorpus, post-vulval uterine sac 99–162 µm long or 2.6–3.8 times as long as the body diameter divided in a short tubular proximal part and a long swollen distal part, vulva post-equatorial (<italic>V</italic> = 63–69), female tail conical elongate with acute terminus (133–170 µm, <italic>c</italic> = 6.8–8.1, <italic>c’</italic> = 4.9–7.0), male tail conical elongate with acute terminus (104–137 µm, <italic>c</italic> = 7.8–10.9, <italic>c’</italic> = 3.6–5.1), and spicules 70–81 µm long having angular hook-like and very curved ventrad lamina ending in a spatulate tip with a refringent forked axis. The evolutionary relationships of this species and the genus <italic>Panagrellus</italic>, as derived from the analyses of 18S and 28S rDNA fragments, are discussed. Additionally, the phylogenetic relationships among the members of the infraorder Panagrolaimomorpha is studied, being the genus <italic>Tarantobelus</italic> transferred to the family Panagrolaimidae and the new subfamily Tarantobelinae n. subfam. is proposed to accommodate it.</p>
</abstract>

The identity of Panagrellus pycnus, the type species of the genus Panagrellus, is discussed after studying specimens from a cultured population collected in Italy that fits the original material of the species. A new characterization is consequently provided as follows: body 0.93–1.32 mm long, lip region continuous with the adjoining body, stoma with gymnostom very reduced, pharynx with not swollen metacorpus, neck 161–203 µm long, excretory pore at level of the metacorpus, post-vulval uterine sac 99–162 µm long or 2.6–3.8 times as long as the body diameter divided in a short tubular proximal part and a long swollen distal part, vulva post-equatorial (V = 63–69), female tail conical elongate with acute terminus (133–170 µm, c = 6.8–8.1, c’ = 4.9–7.0), male tail conical elongate with acute terminus (104–137 µm, c = 7.8–10.9, c’ = 3.6–5.1), and spicules 70–81 µm long having angular hook-like and very curved ventrad lamina ending in a spatulate tip with a refringent forked axis. The evolutionary relationships of this species and the genus Panagrellus, as derived from the analyses of 18S and 28S rDNA fragments, are discussed. Additionally, the phylogenetic relationships among the members of the infraorder Panagrolaimomorpha is studied, being the genus Tarantobelus transferred to the family Panagrolaimidae and the new subfamily Tarantobelinae n. subfam. is proposed to accommodate it.

<article-title xml:lang="en">Redescription and phylogenetic analysis of the type species of the genus <italic>Panagrellus</italic> Thorne, 1938 (Rhabditida, Panagrolaimidae), <italic>P. pycnus</italic> Thorne, 1938, including the first SEM study

Journal of Nematology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Redescription and phylogenetic analysis of the type species of the genus  Thorne, 1938 (Rhabditida, Panagrolaimidae),  Thorne, 1938, including the first SEM study

The identity of Panagrellus pycnus, the type species of the genus Panagrellus, is discussed after studying specimens from a cultured population collected in...

Redescription and phylogenetic analysis of the type species of the genus Panagrellus Thorne, 1938 (Rhabditida, Panagrolaimidae), P. pycnus Thorne, 1938, including the first SEM study

Published Online: Oct 01, 2021

Page range: 1 - 20

DOI: https://doi.org/10.21307/jofnem-2021-080

Keywords
18S rDNA, 28S rDNA, Description, Molecular analysis, Morphology, Phylogeny, SEM, Tarantobelinae n. subfam., Taxonomy

© 2021 Joaquín Abolafia et al., published by Sciendo.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Redescription and phylogenetic analysis of the type species of the genus Panagrellus Thorne, 1938 (Rhabditida, Panagrolaimidae), P. pycnus Thorne, 1938, including the first SEM study

Published Online: Oct 01, 2021

Page range: 1 - 20

DOI: https://doi.org/10.21307/jofnem-2021-080

Keywords18S rDNA, 28S rDNA, Description, Molecular analysis, Morphology, Phylogeny, SEM, Tarantobelinae n. subfam., Taxonomy

© 2021 Joaquín Abolafia et al., published by Sciendo.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
18S rDNA, 28S rDNA, Description, Molecular analysis, Morphology, Phylogeny, SEM, Tarantobelinae n. subfam., Taxonomy