Whitebait

Whitebait is a collective term for the immature fry of fish, typically between 25 and 50 millimetres long. Such young fish often travel together in schools along coasts, and move into estuaries and sometimes up rivers where they can be easily caught using fine-meshed fishing nets. Whitebaiting is the activity of catching whitebait. Individual whitebait are tender and edible, and are considered a delicacy in New Zealand. The entire fish is eaten — including head, fins, bones, and bowels. Some species make better eating than others, and the particular species that are marketed as "whitebait" vary in different parts of the world. As whitebait consists of immature fry of many important food species (such as herring, sprat, sardines, mackerel, bass and many others) it is not an ecologically viable foodstuff and several countries impose strict controls on harvesting.

Source: Wikipedia