Hygrobates calliger Piersig, 1896

Pešić, Vladimir, Jovanović, Milica, Manović, Ana, Karaouzas, Ioannis & Smit, Harry, 2021, New records of water mites from the Balkans revealed by DNA barcoding (Acari, Hydrachnidia), Ecologica Montenegrina 49, pp. 20-34 : 28-29

Hygrobates calliger Piersig, 1896

Hygrobates calliger , a rhitrobiontic species, inhabiting lower, middle and high order streams, is widely distributed in the Palaearctic ( Gerecke et al. 2016). A single specimen collected in the Mornos River in Greece and successfully barcoded in this study, matches the description of H. calliger . The final alignment for species delimitation using COI sequence data in this study comprised sequences of 12 specimens of Hygrobates calliger , and two species, H. foreli and H. fluviatilis were used as outgroups ( Table 6). The final alignment consisted of 658 nucleotide positions. The neighbour-joining (NJ) tree is presented in Fig. 4 .

We delineated three H. calliger haplogroups. The sequences from Italy form a strongly supported clade (HygC-I) recovered as a sister clade of the haplogroup (HygC-II) which includes specimens from Montenegro, Greece and Norway. The presence of a high 19.6±2.2% K2P divergence between these two clades indicates that these represents separate species. The Italian populations should be probably assigned to Hygrobates italicus Thor, 1927 , a member of calliger -species group. This species was originally described by Thor (1927) from Arno stream in Toscana ( Italy) but was later on synonymized with H. calliger .

Two specimens from Montenegro and Germany form a third cluster (HygC-III). In our COI tree, the latter haplogroup was recovered as a sister clade to the two other H. calliger clades with a high interspecific distance which ranged from 17.0±1.9 to 20.9±2.2% K2P ( Table 7 ) indicating the species status of this clade. To clarify the taxonomic status of the above described H. calliger barcode lineages, more specimens from Europe should be barcoded including specimens from the type localities of H. calliger and H. italicus .

Figures

Figure 4. Neighbour-joining tree based on studied Hygrobates calliger COI sequences.