Herring are forage fish, mostly belonging to the family of Clupeidae.
Atlantic herring, Clupea harengus
Herring spawn
Transparent eggs with the yolk and eyes visible and one larva hatched.
Freshly hatched larva in a drop of water beside a match to demonstrate how tiny it is: The black eyes and the yolk are visible.
Forage fish, also called prey fish or bait fish, are small pelagic fish that feed on plankton and other tiny organisms. They are preyed on by larger predators, including larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the food chain on plankton, often by filter feeding. They include particularly fishes of the order Clupeiformes, but also other small fish, including halfbeaks, silversides, smelt such as capelin and goldband fusiliers.
These small goldband fusiliers are typical forage fish. They swim in large schools for protection from larger predators.
Copepod
Herring ram feeding on a school of copepods
Image: Anchovy closeup