This large group of animals, namely, marine finfish, belonging to which belong to the Osteichthyes category (from the Greek ‘osteos’ = bone, and ‘ichthyos‘ = fish), is characterised by the existence of an internal skeleton of an osseous origin and, in the majority of cases, by the existence of gills, dorsal fins and a mouth in a frontal position.
In accordance with their distribution in relation to the water column, can be classified in four groups:
- Pelagic – fish that live in the water column, generally in a shoal, and without being very close to the seabed. Examples: mackerel, sardine, tuna, etc.
- Demersal – these live the majority of their lifecycle around the seabed, whether rocky or sandy beds. Examples: groupers, parrotfish, hake, scorpionfish, etc.
- Bathypelagic – these live at great depths (between 1000m and 4000 m).
- Mesopelagic – fish that normally live on the seabed during the day and migrate vertically close to the service at night.