engleski

Telestes karsticus – a cave adapted fish in the Dinaric Karst

Animals that are not fully troglomorphic are often neglected in cave biology studies. However, they can provide important insights into the early stages of cave colonization. This is especially true when a surface population is also present and available for comparative studies. Although fishes are not uncommon in caves of the Dinaric Karst, it is generally believed that there are no cave-adapted fishes in this region. Several genera of fishes, such as Delminichtys, Telestes, and Phoxinellus, are known to be associated with caves, as they have been reported to retreat to caves during dry periods and spend several months underground until favorable conditions return. Data on such populations and their occurrence in caves are sparse, but during recent intensive surveys of Sušik Cave, Velika Kapela Mt, Croatia, cavers have frequently encountered fish. Sušik cave is a sinkhole of the small stream inhabited by a single endemic fish species, Telestes karsticus. Therefore, we set out to investigate whether T. karsticus lives permanently in Sušik Cave, how large the cave population is, and whether it exhibits any cave-adaptive characteristics. Our results show that T. karsticus lives in Sušik Cave throughout the year and its population is estimated to be several hundred individuals. Moreover, we found morphological and physiological characteristics that clearly distinguish it from the neighboring surface population. Therefore, Telestes karsticus forms a permanent cave population and the presence of a conspecific surface population makes it a potentially important model system for understanding the initial adaptive processes that occur during cave colonization.

cavefish ; troglomorphies ; cave colonization and adaptation

nije evidentirano