SIZE:
Generally less than 30 cm.
LIFE EXPECTANCY:
Up to 10 years.
LIFE CYCLE:
Sexual maturity is around 4 or 5 years of age.
Alewives are born in lakes or the calm stretches of rivers in late spring. Juvenile fish remain in fresh water until the autumn, during which they swim to the ocean or deeper waters. Adults will return to fresh water in the spring to spawn and then head back out to sea.