To Registrations of Bottom Macroinvertebrates, Fish, Amphibians and Reptiles of the upper Tskhenistskali River Basin (Georgia, Lower Svanetia)

Abstract

This paper contains information on the records of bottom macroinvertebrates, fish, amphibians and reptiles collected during a fi eld expedition to the valley of the river Tskhenistskali (in the vicinities of town of Lentekhi and village of Sasashi) in April 2018. According to the results of the study, three fish species (Actinopterigii) of three families (Salmonidae, Cyprinidae and Nemacheilidae) inhabits three studied rivers (Kheledula, Devashi and Tskhenistskali Rivers). Seven species of reptiles (Squamata: Anguidae — 1, Colubridae — 1, Viperidae — 1, Lacertidae — 4), and five species of amphibians (Anura: Hylidae — 1, Bufonidae — 1, Ranidae – 2; Caudata: Salamandridae — 1) were registered within the investigated area. Around Lentekhi town three species of the genus Darevskia Arribas, 1999, namely Darevskia rudis svanetica (Darevsky & Eiselt, 1980), Darevskia brauneri brauneri (Mehely, 1909) and Darevskia derjugini abchasica (Bischoff , 1982) were found to live almost sympatrically, with only river serving as a natural barrier between the species. The paper also contains descriptions of habitats characteristic of the region for the species found and the results of route surveys with D. d. abchasica and P. ridibundus being the most numerous species of herpetofauna (sensu lato) — up to 35 and 20 individuals per 100 m of route. In order to illustrate the feeding base of the registered vertebrates, the study of species composition (n = 114) of bottom macroinvertebrates, that form the main component of food source for them. The recorded invertebrates belong to 16 taxonomic groups of the higher rank (up to 98.1 % of all benthic invertebrates appeared to be insects, including Ephemeroptera — 51 %, Plecoptera — 17.4 % Сhironomidae — 14.2 %, Trichoptera — 11.5 %, Diptera — 3 %). Other groups, namely Turbellaria, Nematoda, Oligochaeta, Araneida, Acarina, Collembola, Heteroptera, Coleoptera, in total form a little less than 3 % of all recorded species. Registrations of fauna from mountain regions will help to update actual maps of natural ranges of the species within the country and tend to be a valuable addition to the data that can be potentially used in GIS-modelling of species’ distribution according to predicted climate changes.