Research Article |
Corresponding author: Aleksi Memishishi ( aleksi.memishishi.1@iliauni.edu.ge ) Academic editor: Roman J. Godunko
© 2023 Aleksi Memishishi, Ani Bikashvili, Bella Japoshvili, Levan Mumladze.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Memishishi A, Bikashvili A, Japoshvili B, Mumladze L (2023) The record of Ametropus fragilis Albarda, 1878 (Ephemeroptera, Ametropodidae) from Georgia. Caucasiana 2: 77-82. https://doi.org/10.3897/caucasiana.2.e102622
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The representatives of the genus Ametropus (Insecta, Ephemeroptera) were recorded 80 years ago in Georgia. Due to the taxonomic uncertainty, the recorded specimens were considered potentially new taxa. Since then, no other record of Ametropus has been documented from the whole South Caucasus and its nearby regions further south. In the present contribution, we provide a new record of Ametropus from the Alazani River (Kura River Basin, Georgia). Morphological and DNA barcoding of the COI gene fragment showed that the species belongs to the widespread Holarctic species A. fragilis. Morpho-anatomical characteristics also confirmed the high degree of similarity between the newly recorded specimens and those once recorded 80 years ago. In addition, the COI barcode showed a strikingly closer relationship between Caucasian A. fragilis and North American A. neavei (3.54% divergence) compared to Caucasian and European A. fragilis populations (4.3% divergence). The observed pattern clearly indicates the need for further and more thorough revision of the Ametropus species complex in the Holarctic region.
Alazani River, CaBOL, faunistics, mayfly, South Caucasus, Vashlovani National Park
The mayfly (Insecta, Ephemeroptera) fauna of Georgia is relatively well known thanks to recent renewed interest (
Benthic samples were collected from three plots (with a 30 meter distance) on April 17, 2022, at Mijniskure, Vashlovani National Park in Georgia (N41.11188, E46.64954, 95 m a.s.l.), in the shallow and murky waters of the Alazani River (Fig.
Samples were collected using a kick-net with a mesh size of 500 μm according to the AQEM sampling method (
Photos of the preserved specimen were taken using a Canon EOS 60D camera with a Canon EF-S 60mm f/2.8 Macro USM Lens. Digital images were prepared using Zerene Stacker image stacking software and Adobe Photoshop CS6.
Genomic DNA was extracted from tissue samples using the Quick-DNATM Miniprep PlusKit (Zymo Research) (for 25 mg of tissue). Partial sequences of cytochrome oxidase subunit I (COI) were amplified by polymerase chain reaction (PCR) using the primer pairs LCO1490-JJ and HCO2198-JJ (
Among the mayfly samples collected in the Alazani River, five specimens were sorted out from the single sample initially identified as Ametropus sp. The nymph morphology of this genus is unique among mayfly genera and cannot be confused (
We obtained three COI barcode sequences from three specimens with 626 nucleotide base pairs free from indels or stop codons. Sequences were uploaded to BOLD Systems (processing IDs EPGEO001-23, EPGEO002-23, and EPGEO003-23). The BOLD System identified these sequences under a new BIN: BOLD: AFB6526. Our newly obtained DNA barcodes were nearly identical (0.15–0.61% uncorrected p-distance). The closest taxon after BOLD System matching was the Nearctic species Ametropus neavei (Walker 1849) from Canada (BOLD: AAW1858, mean p-distance 3.54%). A larger genetic distance (4.3%) was found between our specimens and the single sequence of A. fragilis from Slovakia (BOLD: AEV8713; private barcode). The genetic relationship is also depicted in the Neighbor-Joining tree given in Figure
From the family Ametropodidae, a single species (Ametropus fragilis) is considered to occur in Europe. The distribution of this species lies within Germany, Italy, Croatia, Poland, Austria, Slovakia, Hungary, Bulgaria, Romania, Estonia, Latvia, and Lithuania (
In the Caucasus, the presence of Ametropus sp. was first reported from unclear localities by
Ametropus fragilis
is usually rare throughout its distribution range, and its population density is very small while its distribution area is very large. Taking this into consideration, large genetic variation, i.e., around 5% divergence of the COI barcode region between populations, is therefore expected. However, the genetic closeness of Georgian populations with North American populations (named A. neavei in BOLD) compared to Georgian and Slovakian populations makes it difficult to interpret the genetic variation. The most intuitive explanation of the observed pattern is the recent translocation and gene flow. On the other hand, given the population characteristics and life-style peculiarities of Ametropus, the observed pattern can also be indicative of the existence of multiple divergent lineages of Eurasian and North American Ametropus and the need for taxonomic revision of the genus. Based on the state of the art of Ametropus taxonomy and our results, we can conclude that the Georgian populations belong to the widespread species Ametropus fragilis. Furthermore, since the Alazani River, where the specimens have been collected, lies right on the border between Georgia and Azerbaijan, we can say that the species also occurs in Azerbaijan. Taking the old literature information into consideration, the Ametropus specimens observed in Iran and Armenia most probably also belong to the same species. Accordingly, in Figure
We are grateful to Lubos Hrivniak (a researcher at the Institute of Entomology, Biology Centre CAS, Czech Republic) for providing us with valuable comments and suggestions. Armen Seropian, Sopio Balkhamishvili, and Marina Bozhadze for their support at Ilia State University. We would like to express our gratitude to the CaBOL project team members for their assistance during the fieldwork and genetic laboratory at Ilia State University. We thank four anonymous reviewers and the editor, Roman J. Godunko, for their constructive remarks, which helped improve the manuscript substantially. We also thank the Agency of Protected Areas for granting us collection (permit #655-0-2-202103182033). This study was funded by the Federal Ministry of Education and Research under grant number 01DK20014A and Ilia State University.