The mullets (order Mugiliformes) are medium to large fishes, with elongated bodies (up to 90 cm maximum total length) and cylindrical section. Their head is often broad, flattened dorsally, terminal or slightly inferior and small to moderate in size. They have two short but well separated dorsal fins. The first has 4 thin spines, while the second has 9-10 soft rays. The anal fin is short and has 2-3 spines and 7-12 soft rays. The caudal fin is emarginate or forked. The pectoral fins are inserted into the body relatively high on the body. The pelvic fins consist of a spine and 5 soft rays, and are located between the pectoral fin and the first dorsal fin.
As additional characteristics of the mullets, many species have no lateral line at all. They also have mechanisms that allow them to filter the water through specialized structures that allow them to capture microalgae, detritus, small invertebrates, microorganisms and in general organic particles on which they feed. Mullets are fish capable of living in waters with a wide range of salt concentrations, and can be found in coastal marine waters, brackish water lakes, estuaries and can even enter fresh waters. They are usually found in waters no deeper than 20 meters.
A common behavior observed in the mullets is the tendency to jump out of the water. These jumps may be part of the specimens' strategy to escape from predators, although there is also some discussion that the purpose of these jumps is to obtain air for gas exchange thanks to an accessory organ located above the pharynx.
There are 75 described species within the order Mugiliformes, which are organized within a family (Mugildae) in which there are 20 different genera.