The first European cave fish of the Barbatula genus was recently discovered in a difficult accessing cave in southern Germany.
The study published in the scientific journal Current Biology, said that this fish was initially discovered by a diver and later identified by researchers. Their genetic analyzes and their geological profile suggest that this animal would be a kind of cave fish, and will have arisen in the last 20,000 years.
Although the evolutionary time of this animal is relatively short, the now discovered fish have shown to have characteristic adaptations of the “true” cave fish.
Jörg Freyhof, coauthor of this study and taxonomist (scientific classifier) of fish, explained that the eyes of the specimens discovered are very small, appearing to have a curvature inward and their color almost disappeared. These fish also have long fins and larger nostrils than fish that live closer to the surface.
It was diver Joaquim Kreiselmaier who spotted the fish in August 2015 while exploring the deeper parts of the Danube-Aach caves system in Germany that can only be reached in particularly dry conditions during summer and autumn.
As soon as he realized that the fish “looked strange”, he took some photographs and showed them to geologist Roland Berka. Later, Freyhof was able to confirm that the fish revealed to have specific adaptations to the existence in caves.
The diver also said that it is very difficult to access the caves “due to the normally poor visibility, strong current, cold temperature and labyrinthine entry”.
In November of the year 2015, Kreiselmaier was able to capture a live specimen, which allowed the researchers to study its characteristics in greater detail. In the year 2016, it captured four more fish, allowing a more in-depth study of its form and genetics.
Based on the morphological and genetic comparison of the surface fish caught upstream and downstream of the cave, the researchers further stated that cave fish are an isolated population.
And the results show that adaptation to underground means can be relatively rapid, requiring only a few thousand years.
If you fond of fishing you have to buy boat battery!