Eels are some of the most fascinating predators found in the ocean. Any species of fish in the Anguilliformes order is considered to be an eel, and with about 800 different specific species known to science, it’s definitely a large family. Eels are elongated in shape, ranging between 5 cm and more than 4 meters in length, and unlike most fish that rely on large fins to make their way through the water, they use serpentine movements to dart through the water by creating waves, even being able to swim in reverse by reversing the direction of the waves.
Most species of eel have a very complex life. They begin as transparent larvae that feed on marine snow and drift through the most shallow waters of the ocean, before becoming glass eels through the process of metamorphosis. Glass eels later become elvers, before seeking out their adult habitats, which can differ depending on the species and family of origin. The development and specific tendencies of eels also depend greatly on the characteristics of the various species, moray eels, for instance, quickly becoming temperamental predators, while garden eels typically living on their own or in smaller groups.
The eel is a highly diverse marine creature, subspecies ranging between the small garden eel, measuring only 40 cm at maximum and featuring a beautiful, rounded and striped body that resembles a snake, to giant morays that can reach huge sizes and weigh up to 30 kg. For moray eels, feeding patterns and anatomic traits can differ greatly depending on their subspecies, the snowflake and zebra moray, for instance, feeding on crustaceans and shellfish, while species like the pink-lipped moray eel thrives mainly in fresh water. A curious, lesser known species is the conger, featuring some of the largest eels in existence and being quite poorly known. These dangerous predators can actually attack humans in certain conditions, and they have been known to grow to about 2-3 meters in length.
Most species of eels live in shallow waters and commonly bury themselves in the sand or behind rocks. They are nocturnal creatures, so they mostly hunt at night, and some species are quite solitary, as well. Moray eels are one of the most striking exceptions to that rule, being known to cooperate between each other and even with fish belonging to other species when hunting for prey! A good example is the roving coralgrouper, which is known to recruit moray eels in shallow reef waters to enter tight crevices and flush out prey from less accessible areas.
Eels can be found almost anywhere in the world, and some species, such as the garden eel can be spotted in places as different as Papua New Guinea and the Phillippines. Moray eels are found in both tropical and temperate areas, although not many species actually dwell outside tropical regions or the subtropics. Finally, the illusive conger is usually found along the coast of Europe and North America, larger specimens being observed by divers in the Mediterranean as well.