Hexanchorus Sharp, 1882

Linsky, Marek, Ciamporova-Zatovicova, Zuzana, Lassova, Kristina & Ciampor Jr, Fedor, 2022, Molecular phylogeny of the riffle beetle genus Hexanchorus revealed a presence of a new genus (Coleoptera: Elmidae), Arthropod Systematics & amp; Phylogeny 80, pp. 575-602 : 575

3.2.1. Genus Hexanchorus Sharp, 1882

Hexanchorus sagittatus Linský, Čiamporová-Zaťovičová & Čiampor Jr, 2019 stat. nov.

Hexanchorus onorei sagittatus Linský, Čiamporová-Zaťovičová & Čiampor Jr, 2019: 100.

Diagnosis.

This species can be distinguished from all known Hexanchorus species by combination of the following male characters: 1) smaller size (CL: 3.22-3.25 mm); 2) antennae long, serrate, with visible stalks; 3) anterior lateral pubescent area of mesotibia reaching to ca 3/5; 4) posterior lateral pubescent area of mesotibia almost reaching apex; 5) mesotibiae with distinct tubercle on inner apex; 6) metatibiae with small tubercle on inner apex; 7) elytral apex almost rounded, with inner margin arcuately produced; 8) fifth ventrite deeply and very broadly emarginate; 9) aedeagus arrow-like in ventral view.

Remarks.

As mentioned in its original description ( Linský et al. 2019), this taxon clearly differs morphologically from other Hexanchorus species, but due to small genetic distance from H. onorei it was originally described as its subspecies. Phylogenetic analysis based on four markers (Fig. 1 ) recovered H. sagittatus stat. nov. as a sister to clade H. cordillierae + H. onorei and thus fully justifies its elevation to the species rank.

Figures

Figure 1. Time callibrated Bayesian phylogeny of Hexanchorus and Rumilara gen. nov. Genera Disersus, Potamophilops, and Pseudodisersus were used as an outgroup.