Alosa vistonica well-developed teeth on the palatine and vomer, especially in juveniles. Alosa vistonica Alosa vistonica is a species of shad, a freshwater fish in the Clupeidae family. It is endemic to a single shallow lake, Lake Vistonida in Greece. It is classified as critically endangered (CR) and is threatened by sewage, industrial effluents, destruction of spawning sites by agricultural development and increased salinity following the opening of a canal into the sea. It has been suspected to be extinct already. "A. vistonica" reaches a maximum length of 17 cm (SL). It is distinguished from other members of its genus entering freshwater
Assabet River followed by deliberate introduction into ponds near the Concord and Sudbury Rivers. This is now an invasive, habitat-destroying plant across many of the eastern states. On the Assabet River, OARS (Organization for the Assabet, Sudbury and Concord Rivers) organizes an annual plant pulling event in early July. Volunteers in canoes hand-pull the surface-floating rosettes of leaves and nuts before the nuts mature and fall to the bottom. Alewife, "Alosa pseudoharengus" is an anadromous species of herring found in North America, anadromous meaning that it mates and is born in fresh water, but live most of its life in saltwater. In