Pontic shad Pontic shad The Pontic shad ("Alosa immaculata", previously "Alosa pontica"), also referred to as the Black Sea shad or Kerch shad, is a species of clupeid fish in the genus "Alosa", native to the Black Sea and Sea of Azov basins. "Alosa immaculata" lives in the Black Sea and Sea of Azov, and adults migrate up rivers to spawn. It may also be found in the Marmara Sea in Turkey. It currently migrates up and spawns in six rivers: the Danube, Dnieper, Dniester, Southern Bug, Don and Kuban Rivers. Previously the migrations reached far upstream, up to 1,600 in Danube
Fish fossil fish but also living gars and bichirs), cycloid, and ctenoid (these last two are found on most bony fish). There are even fish that live mostly on land or lay their eggs on land near water. Mudskippers feed and interact with one another on mudflats and go underwater to hide in their burrows. A single, undescribed species of "Phreatobius", has been called a true "land fish" as this worm-like catfish strictly lives among waterlogged leaf litter. Many species live in underground lakes, underground rivers or aquifers and are popularly known as cavefish. Fish range in size from the huge