Diversity of Coomansus zschokkei-group (Nematoda, Mononchida) in Bulgaria

Abstract

The genus Coomansus Jairajpuri & Khan, 1977 encompasses more than 30 species occuring in various habitats. The Coomansus zschokkei-group, characterized by a posterior position of the dorsal tooth, includes 11 species spread in the northern hemisphere: Europe (3 species), Asia (Far East, Korea, Japan – 8 species), North America (Costa Rica and USA – 1 species), which are reported from subalpine habitats and forests, but also freshwater lakes. So far, one species (C. zschokkei (Menzel, 1914)) was recorded from Bulgaria (Iliev and Ilieva 2019). During this study three undescribed species have been found from mountain areas of Bulgaria. These three closely related Coomansus species were studied using an integrative approach. Based on the dimensions of the buccal capsule and the posterior position of the dorsal tooth they are similar to C. zschokkei, C. cobbi (Eroshenko, 1975), C. mucronatus (Eroshenko, 1975) and C. simenensis (Kreis, 1924), but differ from them by a number of characters such as buccal capsule length, tail length, and lateral piece shape. Coomansus cf. menzeli Loof & Viniszewska-Slipińska, 1993 recovered from moss around birch tree at the Central Balkan Mountain is a new geographical record for Bulgaria. Phylogenetic analyses based on 18S and D2-D3 expansion domains of rRNA genes have been performed for the first time for members of Coomansus zschokkei-group. In both phylogenetic reconstructions, all Coomansus species with the exception of C. gerlachei (De Man, 1904) formed a monophyletic group with very high bootstrap support values. Speciation within the group seems to be related to glaciation and post-glaciation events in mountain areas.

New record of the genus <i>parkellus</i> jairajpuri, tahseen & choi (mononchida: mononchidae) with redescription of <i> parkellus menzeli </i> male in Vietnam

“…Up to now, of ten already described species in this genus worldwide (Ahmad & Jairajpuri, 2010), three species from Europe; eight species from Asia including Far East, Kazakhstan, Korea, Japan 8 species and one species from North America. The species P. menzeli was recorded only in Europe including Poland, Switzerland, Czech Republic, Romania, Ukraine and Bungaria (Ahmad & Jairajpuri, 2010;Mladenov et al, 2019).…”