New cave species discovered in Krka National Park

A new species of cave beetle has been officially identified in Krka National Park, further underscoring the extraordinary diversity hidden beneath the Park’s surface.

The species, Bryaxis krkensis, known as the Krka cave beetle, has been named in honour of the Park where it was first found, Krka National Park said today.

The beetle was initially collected in 2015 during research into Krka’s cave fauna by members of the Croatian Biospeleological Society.

The specimens, both male and female, were discovered in a tufa cave in the area of Bilušića buk. A second finding followed in 2023, when the species was also recorded in a pit near Kaštel Žegarski.

Although researchers recognised early on that the material represented a new species, the demanding nature of the taxonomic work meant that its official description took time to complete.

(Photo: Krka National Park)

Despite its important scientific role, the Krka cave beetle is remarkably small.

Measuring just 1.70–1.75 millimetres in length and up to 0.69 millimetres in width, it is built of three main body parts and displays a reddish-brown, shiny surface. Its head is roughly equal in length and width and carries long antennae.

The body is dotted with tiny spots and covered in short, even and golden hairs. Its legs are slender, with slightly thickened femora, thinner in females, who also have smaller eyes.

(Photo: Krka National Park)

The species is considered a top predator within its subterranean food web. Because of its very limited range, any disturbance affecting other cave organisms can directly threaten its survival.

This makes Bryaxis krkensis a particularly vulnerable cave species.

The discovery is a significant reminder of the richness and uniqueness of Krka’s underground world, much of which continues to be explored and understood.