Anchovies are small green fish with blue reflections due to a silver stripe that runs from the base of the . They range from 2 centimetres (0.79 in) to 40 centimetres (16 in) in adult length, and the body shape is variable with more slender fish in northern populations.

The snout is blunt with small, sharp teeth in both jaws. The snout contains a unique , believed to be sensory in nature, although its exact function is unknown. The mouth is larger than that of and , two fish anchovies closely resemble in other respects. The anchovy eats and (recently-hatched fish).

They are found in scattered areas throughout the world's oceans, but are concentrated in temperate waters, and are rare or absent in very cold or very warm seas. They are generally very accepting of a wide range of temperatures.