Alosa Alosa Alosa is a genus of fish, the river herrings, in the family Clupeidae. Along with other genera in the subfamily Alosinae, they are generally known as shads. They are distinct from other herrings by having a deeper body and spawning in rivers. Several species can be found on both sides of the Atlantic Ocean and Mediterranean Sea. Also, several taxa occur in the brackish-water Caspian Sea and the Black Sea basin. Many are found in fresh water during spawning and some are only found in landlocked fresh water. These fishes lived from the Eocene to Quaternary (from 55 million
Weymouth Back River Whitman's Pond was dammed to turn the machines which processed the natural bog iron for the Weymouth Iron Works. Later, the Commonwealth of Massachusetts installed a herring ladder to allow the herring to bypass the dam on their spawning runs. Historically the herring ran to Whitman's Pond, and beyond up Mill River and Swamp River, to Great Pond. River herring commonly refers to two species, Blueback herring ("Alosa aestivalis") and alewife ("(Alosa pseudoharengus)"). Today, 1/2 million river herring and Rainbow smelt ("Osmerus mordax") run up the river each year to spawn (although they are not able to ascend the fish