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
Herring as food the cancer-causing effect of PCBs and dioxins. The contaminant levels depend on the age of the fish which can be inferred from their size. Baltic herrings larger than 17 cm may be eaten twice a month, while herrings smaller than 17 cm can be eaten freely. Mercury in fish also influences the amount of fish that women who are pregnant or planning to be pregnant within the next one or two years may safely eat. Herring has been a staple food source since at least 3000 B.C. There are numerous ways the fish is served and many regional recipes: eaten