Alosa braschnikowi Alosa braschnikowi Alosa braschnikowi, the Caspian marine shad or Brazhnikov's shad, is one of the clupeid fish species endemic to the Caspian Sea. This is a relatively large shad, typically 30 cm and up to 50 cm length. It also has a more "herring-like" body shape than other Caspian shad species, being a slender and elongate fish. It has well developed teeth in both jaws. "Alosa braschnikowi" feeds on small fishes but also on crustaceans and occasionally other invertebrates. It performs migrations within the Caspian Sea, but does not enter rivers. Several subspecies have been described, with different breeding habits
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