The project is intended to gain a first insight into the present-day biodiversity of turbellarians in Austria. Morphological and genetic data will be used in parallel. For practical reasons, the focus lies on eastern Austria.

The turbellarians (former class „Turbellaria“ in the phylum Platyhelminthes) are the flatworms (Platyhelminthes) excluding the exclusively parasitic, monophyletic Neodermata. In contrast to these, the majority of turbellarians are free-living predators. Therefore, the turbellarians are also often referred to as the “free-living flatworms”. They are unsegmented, acoelomate, hermaphroditic animals with a multiciliate epidermis. In Austria, they inhabit lentic and lotic waterbodies, groundwater and moist soils. In addition, there are fully terrestrial microscopic alpine turbellarians and land Planarians (Geoplanidae), and marine turbellarians that occur in marine aquaria. The turbellarians are common and ubiquitous in freshwater habitats. Nonetheless, they are one of the least investigated groups of animals in Austria and worldwide.

For the current project, animals are collected mainly from freshwater habitats using a plankton net. The samples are brought to the laboratory and live turbellarians are isolated from the sample. They are investigated alive under the microscope and then fixed appropriately for histological or molecular genetic investigation. The identification of turbellarians relies mostly on microscopy of live specimens, but in some cases, it requires the interpretation of histological serial sections. The main molecular markers will be the nuclear ribosomal RNA genes, such as the 18S and 28S rRNA genes, which are established molecular markers for turbellarians. It is planned to amplify the mitochondrial COI gene as well, which will likely require the design of new primers for certain taxa.

The project will result in a first contribution towards a species inventory of turbellarians in Austria. Reference sequences from some well-determined species will be uploaded to public databases. Serial sections or whole-mounts will be deposited in the turbellarian collection of the Natural History Museum of Vienna. The study also aims to simplify identification of turbellarians by extensively documenting the morphology of specimens photographically. Due to the poor knowledge of the group in the study area, the discovery of cryptic or entirely undescribed species is likely.