In October, members of eDNALabs, Teja Muha and Lucija Markulin, visited the Institute for Biological Research “Siniša Stanković” (IBISS), a leading multidisciplinary scientific institution in Serbia specializing in biological sciences. Hosted by Stoimir Kolarević, the main organizer of the workshop, and other members of the IBISS team, eDNALabs team members held an intensive three-day workshop on environmental DNA analysis, covering everything from field sampling to data analysis.

Workshop started with water sampling and filtration on the first day. Sampling activities were done at River Gradac near Valjevo, where both teams collected water samples for eDNA analysis.  IBISS team also performed conventional monitoring using electrofishing method at the same time to be able to correlate traditional monitoring data with results of eDNA molecular analysis.

Following day was dedicated to laboratory work, where Teja Muha and Lucija Markulin guided the participants through the steps involved in eDNA extraction and preparation of reactions for species-specific detection using ddPCR. For this practical demonstration, assays developed by the eDNALabs team were used, showcasing the technology’s potential for identifying Thymallus thymallus (European Grayling) and Salmo trutta (brown trout) in the water samples.

Visit and workshop were concluded with final analysis and comparison of the results of ddPCR assays and the outcomes of the electrofishing activities, followed by the presentation on ongoing eDNA Labs projects and ideas for future collaborations.

Based on previously reported presence of specimen and abundance of species in the area, eDNA Labs team visited Podravje Region in Slovenia aiming to collect water samples and detect Spinycheek crayfish in gravel pits adjacent to Drava River.

The goal of this field research expedition was to confirm Spinycheek crayfish presence by molecular method based on its environmental DNA detection applying digital droplet PCR. The eDNA Labs team has so far developed molecular assays for several of crayfish species native and invasive, Spinycheek crayfish (Faxonius limosus), Noble crayfish (Astacus astacus), White-clawed crayfish (Astropotamobius torrentium) and Signal crayfish (Pacifastacus leniusculus), all ready for service provision.

Spinycheek crayfish (Faxonius limosus or Orconectes limosus) is one of the invasive crayfish species known to be present in Slovenia. Native to North America, it was deliberately brought to Europe in 19^th century to substitute the native European crayfish (also known as Noble crayfish (Astacus astacus)) that was decimated by crayfish plague, introduced by its closely related crayfish species Pacifastacus leniusculus. The action was later found to be counterproductive as due to spinycheek crayfish small size, the crayfish species was not commercially interesting. It has even enabled further spread of crayfish plague.

Today F. limosus poses a threat for multiple reasons. As mentioned, it is a carrier of crayfish plague (to which itself is insensitive), it propagates and grows faster than native species of European crayfish and stone crayfish (Austropotamobius torrentium), over-competing them for food. Stability of ecosystem is therefore compromised.