Zeiformes are an order of saltwater-dwelling fishes, usually swimming near the bottom of deep waters between 35 and 1,500 meters. A total of 33 species are known, which are classified forming 3 suborders (Caproidei, Cyttoidei and Zeioidei) and 7 families (Caproidae, Cyttidae, Grammicolepididae, Oreosomatidae, Parazenidae, Zeidae and Zenionidae). In the Atlantic, Indian and Pacific oceans, as well as in many seas such as the Mediterranean, we can find species of this order of fish, some of which during the winter months may approach more coastal waters.

The distinguishing characteristics of the zeiformes species are an oval-shaped body, tall and very compressed laterally, with a large head equipped with very protractile jaws and large eyes. They have two dorsal fins with 5-10 spines and 22-36 soft rays; two anal fins and the caudal fin usually has 11 branched rays, although there are species with 13. Many species have very elongated dorsal fin spines, often with filamentous tips, while the soft rays are usually unbranched. It is also common for species of this order to have bony spiny plates distributed throughout the body. Most species have silver, bronze, brown or reddish colors, and often have the ability to change their body coloration in a matter of seconds. In general, females and males of zeiformes do not usually show clear sexual dimorphism, although females tend to be slightly larger than males.

In terms of size, the shortest species is Macrurocyttus acanthopodus which usually does not exceed 5 cm in total length, while the opposite extreme is for the species Zeus capensis whose specimens can reach up to 90 cm in total length.

Mostly carnivorous, zeiformes base their diet on the capture of crustaceans, other fish and cephalopods.