Alosa braschnikowi and with varying gill raker numbers. The suggested subspecies include: Even "Alosa curensis" and "Alosa maeotica" have sometimes been listed as subspecies of "A. brashnikovi"; the latter is from the Pontic basin and now considered distinct (non-Caspian) species. Several further synonyms exist. 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
Coastal fish but ascend rivers to spawn; eels are catadromous, living in rivers and streams, but returning to the sea to breed. Besides the species that migrate through estuaries, there are many other fish that use them as "nursery grounds" for spawning or as places young fish can feed and grow before moving elsewhere. For example, herring and plaice are two commercially important species that use the Thames Estuary for this purpose. Mangrove swamps are associated brackish water habitats. Many, though not all, mangrove swamps fringe estuaries and lagoons where the salinity changes with each tide. Among the most specialised residents of