- Source: Pneophyllum cetinaensis
Pneophyllum cetinaensis is the only known species of freshwater coralline algae endemic to Croatia. Its ancestor lived in brackish water, and was already adapted to osmotic stress and rapid changes in water salinity and temperature. P. cetinaensis differs from other coralline red algae species in that it forms extensive and conspicuous crusts thickened with multi-layered flattened or curved branches. It also has a pore canal of simple conceptacles which are not surrounded by specialised cells. It also the only known coralline red algae species which confined to a freshwater stream as opposed to saltwater marine environment. It was first identified in 2016 and was found in the Cetina River.
