DNA barcodes evidence the contact zone of eastern and western caddisfly lineages in the Western Carpathians

The region of the Western Carpathians is, among other aspects, very important for survival and diversity of European freshwater fauna due to the presence of a large number of (sub)mountain springs and streams. However, these ecologically and faunistically diversified habitats are still understudied in the context of genetic diversity and population structure of their inhabitants. This study focuses on genetic diversity and distribution patterns of the caddisfly Rhyacophila tristis, common and widespread representative of mountain freshwater fauna. Analysis of the COI mitochondrial marker revealed presence of the western and eastern lineages, with samples from both lineages being grouped in BOLD (Barcode of Life Data System) into separate BINs (Barcode Index Numbers). Our data indicates that eastern lineage (BIN_E) is more closely related to the Balkan populations than to co-occurring western lineage (BIN_W), and that the contact zone of the lineages passes through the W Carpathians. The study revealed phylogeographic and demographic differences between lineages, supporting hypothesis of their evolutionary independence and specific ecological preferences. The obtained genetic data of the R. tristis population from W Carpathians improved our knowledge about population genetics of this aquatic species and can contribute to understanding the state and evolution of biodiversity of freshwater ecosystems in Europe.

The value of DNA barcoding in a hotspot area: an example of Rhyacophila tristis (Trichoptera) in the Western Carpathians

DNA barcoding has proven to be an essential tool in providing molecular tags for animal species. In addition, the value of DNA barcoding undoubtedly consists in giving information about intraspecific genetic diversity, which is of great importance for biodiversity monitoring and conservation assessments. Such data are especially valuable in case of biodiversity hot-spots. Therefore, the aim of our study was to expand the knowledge of the genetic patterns and distribution of the caddisfly Rhyacophila tristis (Trichoptera, Rhyacophilidae) population in one such biodiversity hotspot - The Western Carpathians. The W Carpathians include rich freshwater systems of springs and streams, where molecular diversity and phylogeographic patterns of aquatic fauna are yet to be fully explored. Based on the mitochondrial DNA barcoding fragment (COI-5P) of 161 sequences, two BINs representing distinct lineages within R. tristis were identified. BIN BOLD:AAD5574 occurred in 16 localities to the west and BIN BOLD:ADL4166 in 44 localities more to the east, with contact zone in the middle of the mountain system (Fig. 1). BIN BOLD:AAD5574 occurred at a significantly narrower altitudinal interval compared to BIN BOLD:ADL4166, but we did not record significant differences in molecular diversity between BINs. Likewise, past population growth was found in both lineages. Both BINs started to expand demographically at the beginning of the Last Glacial Maximum, however BIN BOLD: ADL4166 increased its demography more sharply compared to BIN BOLD:AAD5574, moreover the effective population size of BIN BOLD:ADL4166 was much higher. BIN BOLD:ADL4166, showing a significantly wider range of altitude, has probably found higher potential for dispersal to various mountain units in the area of the W Carpathians. Our results showed also that BIN BOLD:ADL4166 is more closely related to the separate R. tristis BIN BOLD: ADL4367 recognized in Bulgaria than to the BIN BOLD:AAD5574 occurring geographically in the same mountain system. Additionally, different patterns of population expansion of BIN BOLD:ADL4166 between springs and streams were found. These differences may have occurred due to specific environmental conditions of the karstic springs, which are considered as relatively isolated aquatic habitats. Our initial study of R. tristis phylogeography in W Carpathians opens several new important questions: Is it possible that BIN BOLD:ADL4166 is expanding from the eastern part of Europe (Bulgaria) to the colder streams in the W Carpathians during the LGM? What role do the W Carpathian springs play in maintaining the genetic diversity and sustainability of R. tristis? Could these relatively isolated aquatic habitats serve as postglacial refugia for R. tristis species? And, maybe also, are they two separate species? This contribution was partially supported by the project VEGA 2/0084/21 and VEGA 1/0127/20.

The tale of springs and streams: how different aquatic ecosystems impacted the mtDNA population structure of two riffle beetles in the Western Carpathians

The Western Carpathians are a particularly interesting part of the Carpathian Arc. According to recent molecular data upon aquatic and terrestrial taxa, this mountain area is an important biodiversity hotspot of Europe. Moreover, the W Carpathians include rich systems of karst springs inhabited by specific fauna, where molecular diversity and phylogeographic patterns are yet to be fully explored. Our study aims to compare population genetic structure and molecular diversity of two related and commonly co-occurring riffle beetles, Elmis aenea (PWJ Müller, 1806) and Limnius perrisi (Dufour, 1843) in the springs and streams of the W Carpathians using the mitochondrial DNA barcoding fragment of the cytochrome c oxidase subunit I gene (COI). The relatively stable thermal and chemical conditions of springs throughout unfavourable climatic settings make these highly specific lotic systems potentially ideal for a long-term survival of some aquatic biota. Populations of both elmid species were relatively homogeneous genetically, with a single dominant haplotype. However, we revealed that E. aenea significantly dominated in the springs, while L. perrisi preferred streams. Relative isolation of the springs and their stable conditions were reflected in significantly higher molecular diversity of the E. aenea population in comparison to L. perrisi. The results of Bayesian Skyline Plot analysis also indicated the exceptional position of springs regarding maintaining the population size of E. aenea. On the other hand, it seems that streams in the W Carpathians provide more effective dispersal channels for L. perrisi, whose population expanded much earlier compared to E. aenea. Present study points out that different demographic histories of these two closely related elmid species are manifested by their different habitat preference and molecular diversity.

Slime moulds occurring in the Bukowiec reserve (W Carpathians)

Two-year studies on the diversity and occurrence of slime moulds in the Bukowiec forest reserve (Pogórze Wiśnickie Region) were undertaken. 31 taxa of slime moulds found are listed. Two species, <i>Hemitricha calyculata</i> and <i>Fuligo levderma</i>, are recorded in Poland for the first time.

Rare, threatened and new for Poland macromycetes found in Bukowiec reserve (W Carpathians)

In the paper 36 rare or threatened, 6 new for Poland and 24 new for Polish Carpathians taxa of macrofungi are presented. They were found during two-years investigations carried out in Bukowiec reserve (Pogórze Wiśnickie region, W Carpathians, S Poland).