Anguilla anguilla (European Eels) occur from Norway to Morocco in the Atlantic, in the Mediterranean, Black, and Azov Seas, and in freshwaters of nearly all of Europe and northern Africa. European Eel adults spawn in deep Atlantic waters near the Sargasso Sea. The eggs hatch into leaf-like larvae (leptocephali) and drift on the Gulf Stream toward Europe, metamorphosing in coastal waters into 'glass eels' and then pigmented elvers. These juveniles migrate upstream and grow as 'yellow eels'. They undergo a second metamorphosis and mature as silver eels, which cease feeding and migrate back to the deep Atlantic Ocean for spawning. Scattered records of European Eels in the San Francisco Bay watershed result mostly from escape or discarded animals from homes and fish markets, but they have also been found in surveys of ballast water in San Francisco Bay. There have been at least 4 records from the San Francisco Bay watershed.