The family Gyrinidae is one of the most interesting groups of aquatic beetles, inhabiting the surface of both still and slow-flowing waters. They are small to medium-sized beetles with a body length of 3 to 18 (in the Czech Republic 3.5 to 8) millimetres, which have evolved to live at the interface between air and water. At first glance, they are striking for their oval, strongly flattened body and their distinctive mode of movement – when disturbed, they move in lightning-fast, chaotic circles and spirals. The middle and hind pairs of legs are transformed into perfectly functional swimming paddles. Their most distinctive feature is the entirely unique adaptation of their visual system – each compound eye is divided into two functionally distinct parts, with the upper part enabling vision above the water’s surface and the lower part below it. In this way, they can monitor both dangers and prey in both environments simultaneously. Adults often form large clusters on calm stretches of the water’s surface, where they hunt for small insects and other animals that have fallen into the water. The larvae live on the bottom or in the surrounding sediment and are also predatory. They are found throughout the world and are thought to constitute one of the oldest known groups of beetles, with origins dating back to the Permian period.

Number of Species:

Family Card

Aulonogyrus concinnus

 

Gyrinus minutus

 

Gyrinus colymbus

 

Gyrinus distinctus

 

Gyrinus marinus

 

Gyrinus natator

 

Gyrinus paykulli

 

Gyrinus substriatus

 

Gyrinus suffriani

 

Gyrinus urinator

 

Orectochilus villosus