The coralline algae, Pneophyllum cetinaensis, was discovered in the Cetina River (Croatia), where it appears to be endemic. The Cetina River is a karst river – a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. As such, the river is rich in dissolved calcium carbonate and a pH similar to seawater, which no doubt allowed coralline to evolve to live here.
The algae was found encrusting on rock and snail shells much the same way as coralline algae behaves on coral reefs. The newly discovered coralline species is unable to survive in brackish water, meaning it is fully adapted for strict freshwater environments.
The discovery is published in Nature’s Scientific Report.
If you’re a freshwater aquarist envious of reefkeepers who have to scrap coralline off their glass and gear, your time has finally come.
Photo right: The Cetina River, where the new FW coralline algae was discovered.
Photo bottom: Pneophyllum cetinaensis encrusting various hard substrates, including a FW snail.