(See Fish Gallery Below) Most of the 174 species of herrings, shads, and sardines are anadromous marine or brackish water species, but some species (alewife as well as gizzard and threadfin shad) occur in freshwater. Six species of herring occur in Virginia. They have been introduced to promote sport fish growth in lakes and reservoirs throughout the country. Adult herrings are silvery, laterally-compressed fish ranging in size from 75-700 mm total length, which lack a lateral line and scales on their head. The "saw-toothed" belly of these fish is composed of sharp pointed scales that create the serrated front edge. They form dense schools which cruse the upper open and shallow waters of lakes and reservoirs. These species are prolific (releasing as many as 30,000 eggs/fish). They spawn throughout the spring and summer by broadcasting their non-adhesive eggs in shallow water where the drop to the bottom and hatch in a few days. Adults are filter feeders on plankton and algae. Growth is rapid and sexual maturity is achieved in the second year. Fish in the herring family are an important link in the food chain because they feed on plankton and are preyed upon by sport fish.