Alosa macedonica Alosa macedonica Alosa macedonica, or the Macedonian shad (also known as "liparia"), is a landlocked species of clupeid fish endemic to Greece. Its single natural occurrence is the freshwater Lake Volvi in northern Greece. It is threatened by habitat loss. "Alosa macedonica" is a member of the "Alosa" genus, whose other species are often anadromous migrating between marine and freshwater. Research suggests that the ancestors of "Alosa macedonica" inhabited marine regions of the Aegean Sea. "Alosa macedonica" have teeth in the palatine and vomer. They have approximately 50 vertebrae and 106-128 gill rakers. They are about 181-230mm in length and
Subterranean river Subterranean river A subterranean river is a river that runs wholly or partly beneath the ground surface – one where the riverbed does not represent the surface of the Earth (rivers flowing in gorges are not classed as subterranean). It should also not be confused with an aquifer which may flow like a river but is contained within a permeable layer of rock or other unconsolidated materials. Subterranean rivers may be entirely natural, flowing through cave systems. In karst topography, rivers may disappear through sinkholes, continuing underground. In some cases, they may emerge into daylight further downstream. Some fish (popularly