Lizardfishes (Aulopiformes) are an order of fishes whose name derives from the Greek 'aulopias' meaning pipe. This is due to the elongated shape of their body. They are species of fish that generally inhabit the coastal seabed up to the outer shelf, although it is rare to find species of lizardfish at depths greater than 1,000 meters and the most common is to find most species in shallow waters.
We are dealing with a group of species that have characteristics that are considered very primitive but at the same time very advanced. Although the length and shape of the body of lizardfishes vary among the different species that constitute this order, and in many cases determined by the habitat and depth range in which they live, we can consider that the body is generally elongated and oval in section. They have a large mouth that extends past the eyes. In the mouth we find numerous teeth of small size and generally needle-shaped. The dorsal fin has 14-16 rays and is located in the anterior third of the body (a feature considered primitive). They have a reduced dorsal adipose fin (primitive feature) located at the level of the middle of the anal fin. The pectoral fins have 13 rays and arise just below the lateral line and in a slightly anterior position than the dorsal and pelvic fins. The pelvic fins are larger than the pectoral fins, have 9 rays and are located in an abdominal position. The anal fin has 10-13 rays. None of the fins have spines (another characteristic considered primitive). As for the characteristics considered more evolutionarily advanced, we can mention, although not exclusive to lizardfishes, that they either have a very poorly developed swim bladder or even a completely absent swim bladder in their anatomy.
Lizardfish are predators that feed on small fish and shrimp. The sexes in lizardfish species are separate, and there is usually sexual dimorphism, mainly based on the colors of the dorsal, anal and pelvic fins. As a curiosity of this order of species, some species of lizardfishes are hermaphrodites, with self-fertilization being possible. There are currently a total of 261 described species, classified into 15 families and 47 genera.
