Description of Ironus telperionensis n. sp. (Nematoda: Ironidae) and two known species of Chronogaster (Nematoda: Chronogastridae) and Paraphanolaimus (Nematoda: Aphanolaimidae) from the Telperion Nature Reserve (Mpumalanga, South Africa)

Abstract

Summary A nematode survey conducted in the Telperion Nature Reserve (Mpumalanga, South Africa) resulted in a new Ironus species being described as well as two known species reported for the first time from South Africa, viz., Chronogaster aspinata and Paraphanolaimus behningi. Ironus telperionensis n. sp. is characterised by a long (1724 (1456-1864) μm) and slender body (50 times longer than mid-body diam.), long stoma (116 (87-129) μm), and a 235 (212-257) μm long tail with a ventral curl at the tip. The new species is morphologically most similar to I. ignavus and I. paludicola. However, the new species can be separated from I. ignavus based on the lower ratio c (7.3 (6.5-8.0) vs 8.0-11.0) and longer stoma (116 (87-129) vs 76-90 μm). Ironus telperionensis n. sp. can be distinguished from I. paludicola by the lower ratio a (49.2 (37.4-53.0) vs 60.0-80.0) and lower ratio c (7.3 (6.5-8.0) vs 8.0-13.0). The 18S rDNA phylogenetic analysis of I. telperionensis n. sp. placed it close to I. elegans (KC133064), whereas the 28S rDNA phylogenetic analysis placed it close to I. tenuicaudatus. The phylogenetic analysis revealed that Ironus is a monophyletic group. Paraphanolaimus behningi was identified based on anteriorly bent vagina in the female, spicule length (106 or 110 μm) and number of supplements (13 or 14) in the male. Chronogaster aspinata was identified based on body length (1127 or 1203 μm), cephalic setae length (7 μm), finely rounded tail terminus without a mucron or additional spines, and no longitudinal ridges. It fits the known description of the species. Although various differences were observed between previously reported populations of these species, the morphometrics of the specimens found in Telperion widen the existing variation in these two species.