Unless you happen to run across one while you are at the beach, or hook one when you are fishing, eels probably aren’t something you spend a great deal of time thinking about. Many people find them to be disgusting and creepy, in much the same way as they think of snakes, and some folks even harbor the mistaken impression that they actually are a type of snake that lives in the water due to their sometimes remarkable resemblance to the mostly land-based reptiles.
Actually, eels are elongated ray-finned fish which belong to the Anguilliformes order of the Actinopterygii class in the animal kingdom, and are fairly closely related to the shark and the tuna. There are four sub-orders of eels, 20 separate families, and over 800 identified species. Most scientists believe that the ancestors of the modern eel developed in the middle to late Cretaceous Period (around 100 million years ago).
Mankind has been fascinated by eels for centuries; the Greek philosopher Aristotle wrote the first ‘scientific’ inquiry into the history of the eel around 350 BC in which he suggested that they were actually a sort of earthworm. For many centuries it was believed that eels were totally unique creatures that reproduced through ‘spontaneous generation’ and it wasn’t until the late 18th century that the eel was finally identified as a type of fish that reproduced the old-fashioned way – through spawning.
Today, eels can be found in most of the world’s oceans and seas as well as in many freshwater lakes, rivers, and streams; eels living in freshwater environments, however, always return to the oceans to spawn. Eels come in an assortment of sizes – ranging from about 5 inches long when fully grown to over 13 feet in length. In general, the largest eel species will be found in the oceans.
Eels are generally ‘bottom-dwellers’ – meaning that they tend to burrow in the mud, sand, or rocks at the bottom of whatever body of water they inhabit – and usually live in relatively shallow water, although some species have been found living at depths of over 13,000 feet. In some cases multiple eels will live in a single hole or crevice, creating what is known as an ‘eel pit’. Most species are nocturnal by nature, and so are rarely seen by most humans.
Eels are carnivorous predators and eat other, usually smaller, fish as well as worms, crustaceans, snails, shrimp, frogs, lizards and, in some cases, other types of eels; being nocturnal, they will usually hunt at night. Contrary to some old wives tales, eels do not normally attack humans for no reason, although many bathers, divers, and fishermen over the centuries have been bitten – and sometimes suffered a serious injury – by eels. Generally speaking, an eel will only attack or bite a person (or most other land-based animals) if it feels threatened by them, or if their home is disturbed; they will not attack humans without provocation, as they do not see us as a food source.
On the other hand, various types of eels have been consumed by humans throughout the world as food for centuries. In Japan – which currently accounts for about 70% of worldwide eel consumption – over 200,000 metric tons of eels are farmed in commercial fisheries annually; ocean eel fishing is an important industry; and eel dishes are an important part of Japanese, Korean, and some Chinese cuisines. Jellied eels have been a popular dish in England – and particularly London – since the mid-18th century, and at one time were a staple dish for London’s poorer residents. In other parts of Europe – particularly Germany, the Netherlands, Poland, Denmark, and Sweden – smoked eel dishes have been popular since the 16th century.
While eel dishes have never been as popular in the cuisines of most parts of the United States and Canada as they are in other parts of the world, eels are farmed or fished in North America on a relatively small scale for use as bait for deep-sea fishing (particularly on the East Coast) and for export to European markets; Ontario in Canada, and Massachusetts, Maine and New Hampshire in the United States are leading producers. Some smaller species of Moray eels (discussed below) are quite popular with home aquarium enthusiasts. Stating in the mid-1990s, a number of commercially fished eel species have been placed on Greenpeace International’s list of critically endangered species in the wild.
So what are some of the more common and interesting types of eels to be found in the world today?
The Moray (technically classified as Muraenidae) is the largest family of eels on earth, encompassing 15 genera and more than 200 unique species of eels. While Moray eels are found all over the world, the vast majority live in the tropical and subtropical oceans of the world. Depending on the specific species, Moray eels can be found in both shallow waters near the shore – particularly in reefs – and in the deepest parts of the oceans.
Among other unique characteristics, many types of Moray eels have two sets of jaws (and teeth); one at the front of their mouths, and a second set further back in their throat. They also have an excellent sense of smell, which helps to compensate for the relatively poor eyesight in most species. Unlike other fish, most types of Moray eels do not have scales, pectoral or pelvic fins, and secrete mucus over their smooth outer skins, giving them a particularly slimy feel.
Several smaller species of Moray eels are known to do well in captivity and have been quite popular with aquarium enthusiasts for the last several decades. Some species of Moray eels are known to accumulate very high levels of ciguatoxins – a substance that is poisonous to man and many other mammals – during the course of their lives which can cause neurological and gastrointestinal problems if consumed; most species of Moray eels are not eaten by man.
The Giant Moray (Gymnothorax javanicus) – as the name indicates – is the largest type of Moray eel in terms of body mass (the less common Slender Giant Moray – discussed below – is actually longer, but thinner). The Giant Moray can reach up to 10 feet in length, and grow to around 70 pounds in adulthood. They will generally have a serpentine shape and can be various shades of brown depending on their age (it is believed that the older they get, the darker they get) often with black spots throughout their body. The head is large whereas the eyes are relatively small given the overall size of the fish.
The Giant Moray is native to the Pacific and Indian oceans and can be found in waters around Japan, Australia, Northern Africa, the Hawaiian Islands, the Red Sea, and many other parts of the Indo-Pacific region. They are often found living in lagoons as well as in or near coral reefs. They are nocturnal feeders, usually spending the daylight hours in crevices in a reef or between rocks on the ocean floor. While they are generally afraid of humans and will swim away if approached, many divers are bitten and injured (sometimes severely) every year as the result of sticking their hands too close to a crevice where a Giant Moray is living. The Giant Moray is one of the types of eel known to accumulate ciguatoxins (previously discussed) throughout its lifetime.
The California (Gymnothorax mordax) is the only type of Moray eel native to the West Coast of the United States and is generally found in the waters of the Pacific Ocean between Santa Barbara in California and Baja California in Mexico. It is one of the very few types of Moray eels that do not live in a tropical or subtropical environment, preferring cooler temperate waters. The California Moray has a relatively thin, snake-like body that will commonly reach up to 5 feet in length and will usually weigh between 20 and 25 pounds. They will generally have a mottled skin that can range from dark brown to green and are believed to live between 25 and 30 years on average.
California Moray eels can generally be found inhabiting tide pools and reefs to a depth of about 60 feet, although they will often be found in far shallower waters around Catalina Island and the California Channel Islands. Their diet consists mainly of other fish, shrimp, and octopus, and they spend the majority of their days nestled between rocks or in crevices with only their heads poking out, normally only coming out to hunt for food or when disturbed.
The Zebra Moray (Gymnomuraena zebra) is a small to medium size eel named for the bright white stripes that circle its normally black or dark red body. The Zebra Moray can range in size from about a foot to almost 5 feet in length, although the average length will usually be between a foot and a half and 3 feet. A native of the Indo-Pacific region, they can be found in the wild from the Eastern coast of Africa to the Hawaiian Islands. The Zebra Moray usually inhabits relatively shallow waters, preferring reefs and rocky areas 5 to 50 feet below the surface.
Interestingly, although the Zebra is considered one of the most ‘reclusive’ of all Moray eels and are rarely seen in the wild except by individuals on night dives, in the last several decades they have become one of the most popular types of eels with aquarium enthusiasts, due both to their unique appearance and the fact that they pose very little threat to most other fish in a home aquarium. Unlike most other Morays, the Zebra’s teeth are flat and blunt as opposed to sharp and pointy, and their diet mostly consists of sea urchins, mollusks and crustaceans, and not other types of fish. Because of their size, if you plan of keeping one most exotic fish dealers recommend at least a 150-gallon aquarium with plenty of larger rocks on the bottom for the Zebra Moray to hide in.
The Mediterranean Moray (Muraena helena) is most commonly found in the coastal waters of the Eastern Atlantic Ocean and (not surprisingly) the Mediterranean Sea. Also sometimes called the Roman Eel, the Mediterranean Moray will range from dark grey to dark brown, and will usually have small darker spots. They can grow up to 5 feet in length, and will normally weigh between 30 and 35 pounds. They prefer rocky areas and can be found at depths ranging from 20 to over 250 feet. The Mediterranean Moray is considered a territorial species of eel and will defend the area it has marked out for itself aggressively against competing predators, including other eels. Its diet consists mostly of other fish, crayfish, and dead creatures that have sunk to the bottom. Unlike the majority of Moray eel types, Mediterranean Morays are eaten by people in some areas – including Spain and Portugal – where it is often served baked, broiled or boiled, and was considered to be a delicacy in Ancient Roman times, which accounts for its nickname.
Also sometimes called the Clouded Moray, Starry Moray and Floral Moray, the Snowflake Moray (Echidna nebulosa) is one of the most beautiful of the Moray varieties and is perhaps the most popular type of exotic eel with home aquarium hobbyists. The Snowflake Moray is native to the Indo-Pacific region and can be found in the wild from the Eastern coast of Africa to the Hawaiian Islands, as well as the coasts of Southern Mexico and Costa Rica down to Columbia. In the wild, they inhabit reefs and rocky areas anywhere from 10 to 100 feet below the ocean surface and normally feed on small fish and crustaceans. Usually growing to around two feet in length, the Snowflake has a white body with multi-colored markings ranging from black to yellowish-green that often resemble snowflakes. In aquarium settings, the Snowflake Moray will generally do well with other fish that are too large for it to swallow, and will usually live for about 4 years. They will normally require a 150 gallon or larger tank with a secure lid, as they are particularly adept at escaping from open-top tanks.
Slender Giant Moray
Also sometimes called the Gangetic Moray, the Slender Giant (Strophidon sathete) is the longest member of the Moray eel family and generally considered to be the longest eel species currently in existence. Routinely reaching (and often exceeding) a length of 12 feet, the largest Slender Giant on record was caught near the mouth of the Maroochy River in Queensland, Australia in 1927 and measured slightly over 13 feet long. The Giant Slender Moray is another native of the Indo-Pacific region and is usually found in muddy, less rocky parts of the ocean floor, estuaries and some rivers – particularly in Eastern Africa, Australia, and New Guinea. The Slender Giant Moray is a fairly unremarkable grey-brown color, which allows it to blend in with the mud in which it prefers to live. It is believed by some researchers that a number of ‘sea monster’ sightings reported by mariners prior to the 18th century were actually close-up views of Slender Giant Moray eels forced closer to the ocean’s surface by storms or earthquakes.
Conger eels are a large genus of eel in the Congridae family and account for some of the largest eels in terms of weight and body mass in the world. Somewhat more adaptable than the Moray, Conger species are routinely found in both the Northern and Southern Hemispheres in both tropical and temperate waters, and can be found in the oceans, lakes, and rivers of all continents with the exception of Antarctica. While most Congers tend to remain in saltwater habitats, some varieties will venture into freshwater environments on a regular basis.
Like the Moray, Congers are usually nocturnal predators and have smooth scale-less bodies. Unlike their cousins, they have only one set of jaws (although some species have two rows of teeth) and most species also have pectoral fin. Also unlike the Moray, several types of Congers are routinely eaten by humans and are considered a ‘game fish’ by deep-sea anglers. In general, the female of a specific Conger species will be larger than the male.
The European Conger (Conger conger) is considered to be the largest eel in the world. The European Conger will generally reach between 5 and 6 feet long and can weigh up to 250 pounds or more, although most will be significantly lighter. They are native to the Eastern Atlantic Ocean and can be found from the coast of Norway all the way down to the coast of Senegal in Western Africa; they can also be found in both the Mediterranean and Black seas.
European Congers will usually have very dark – sometimes black – skin on their back and sides which will lighten to pale grey or white on its underside. They will generally be found in relatively shallow water between 15 and 150 feet deep, although older European Congers will sometimes be found living at depths of almost 4,000 feet. They generally prefer to live in rocky areas of the ocean floor, and will sometimes share holes or crevices with other smaller species of eels – particularly Morays – creating an ‘eel pit’. Their diet consists of smaller live fish and crustaceans, as well as whatever dead fish and other marine creatures they can scavenge from the ocean floor. The European Conger is considered a game fish by many European anglers and is considered to be a delicacy in some cuisines.
Also sometimes called the Dog eel, the American Conger (Conger oceanicus) is native to the Western Atlantic Ocean and can be found from Cape Cod on the Massachusetts coast of all the way down to the Northeastern coast of Florida; it is also sometimes found along the coast of Nova Scotia in Eastern Canada and in the Gulf of Mexico. American Congers are generally dark grey with white undersides, and some will have a bluish or reddish tinge. They can reach over six feet in length and up to 90 pounds, although most will be somewhat smaller. Rarely seen in freshwater habitats, American Congers generally prefer to stick relatively close to the shoreline and will typically be found on the ocean floor at depths from 50 to 150 feet. They normally eat other fish, crustaceans, and mollusks. At one time the American Conger was widely commercially fished – particularly in the coastal New England states – and is still offered as specialty dish in some restaurants. It is said to have a complex flavor, similar to squid and octopus.
Longfin African Conger
Also sometimes called the Blacklip Conger, the Longfin African Conger (Conger cinereus) is a Conger variety that is only found in the warmer waters of the Indo-Pacific region. The Longfin African can be found in waters off the coast of Eastern Africa, Japan, Australia, as well as in the Red Sea and the Persian Gulf. Most often growing to between 3 and 4 feet in length, the Longfin African Conger is normally dark grey with a yellowish underside and fins; they will also sometimes appear to have dark bands around their bodies, particularly when seen at night. They normally inhabit shallow shore areas and lagoons – particularly reef areas and beds of seagrass – but can also be found in estuaries and on reef slopes to a depth of about 250 feet. Like most Congers they have a single jaw but possess two rows of teeth. They feed mostly at night on small fish and crustaceans.
Indian Pike Conger
Also sometimes referred to as the Conger Pike and Daggertooth Pike Conger, the Indian Pike Conger (Congresox talabonoides) is native to the Western Pacific and Indian oceans and can be found off the coasts of India, Sri Lanka, Somalia, Indonesia, China, the Philippines, and Taiwan. The Indian Pike Conger will usually be light brown or grey, with a white to the light yellow underside and lower jaw. It will usually grow to between 5 and 6 feet in length and is characterized by a very large head and an extremely large mouth which extends beyond the eyes. Generally living in the mud and soft sediment at depths between 2,000 and 3,000 feet, it rarely ventures close to shore and normally eats bony fish and shrimp. It has been commercially fished for decades and is widely available fresh throughout India, China, and parts of Southeast Asia. It is most often grilled or broiled.
The Japanese eel (Anguilla japonica) is a mostly freshwater eel found in the wild in rivers and lakes throughout Japan (hence their name), China, Korea, Vietnam, and the Philippines. At some point in their life cycle, they will return to the saltwater of the Pacific Ocean to spawn. Japanese eels will usually be brown and white or silver when fully grown, and will grow to about 3 feet in length. They normally eat bony fish, freshwater crustaceans, and insects. The Japanese eel is an important commercial fish, particularly in Japan where they are raised in commercial fisheries and specially designed aquaculture ponds, and hunted in the wild. They are widely used in Japanese, Chinese and Vietnamese cuisines and are always served cooked – in most cases grilled or broiled. Due to changing climatic conditions, over-fishing, and pollution of their spawning areas, the Japanese eel is currently an endangered species in the wild.
Not to be confused with the American Conger, the American eel (Anguilla rostrata) is a freshwater eel and can be found living in rivers, lakes and estuaries on the East Coast of North America including the Hudson and St. Lawrence River and Chesapeake Bay regions, as well as river systems further south, all the way to the Gulf of Mexico. Like all freshwater eels, they return to salt water to spawn – in their case to the Sargasso Sea in the North Atlantic. American eels are usually long and thin (reaching about 4 feet in length and weighing less than 20 pounds) and can range from light brown to olive / yellowish-green with grey or white undersides. They tend to prefer more sandy and gravelly areas close to the shore, and will usually live at depths between 5 and 10 feet. Along with the usual eel fare of crustaceans, they also feed on both aquatic and any land-based insects that venture into their area. Commercially, the American eel is farmed on a very limited basis and used as bait for deep-sea bass fishing, and some culinary applications. Unfortunately, it has recently found its way onto the list of endangered species in the wild, due in large part to river pollution and blockage of the migration routes they use for spawning by hydroelectric and other types of dams.
Again not to be confused with the European Conger, the European eel (Anguilla anguilla) can be found throughout the coastal areas of most parts of Europe, as well as in rivers, lakes, and estuaries throughout the continent. They can be found in both salt and freshwater from the Scandinavian countries in the North Atlantic all the way down to Morocco as well as the Black, Mediterranean, White, and Baltic Sea regions. Like the American eel, it is believed to return to the Sargasso Sea to spawn. Adult eels will generally grow to between 2 and 3 feet in length, although some may grow up to 5 feet. Depending on the age, they can be light brown, brownish-yellow, or a dull silver color with a grey or white underside. Along with the Japanese variety, the European eel is one of the most economically important species on the planet, and are widely commercially farmed and fished throughout Europe. They are an important part of many European cuisines (including the previously mentioned British ‘jellied eel’ dish), and commercially exported to Asia – most often Japan. Due in large part to over-fishing and (mostly man-made) environmental changes, the European eel is considered to be a critically endangered species in the wild. In captivity, European eels are known to live over 80 years.
Garden eels (Heterocongrinae) are a sub-family of the Congridae family of eels to which the previously discussed Conger eel belongs. Comprising about 35 separate species, Garden eels can be found throughout the Indo-Pacific region, warmer Atlantic regions, and the Caribbean and Mediterranean seas. Garden eels will generally range from a little over a foot to over 2 feet in length; can be various shades of brown, yellow, green, white and mottled; and can have speckles, spots, stripes or other designs on their bodies. Garden eels prefer sandy or muddy areas of the ocean floor anywhere from 25 to 200 feet below the surface. They burrow into the soft ocean floor, and will usually stick the top third of their bodies out while keeping the rest buried and eat pretty much anything that swims past them that is small enough. Garden eels are a communal type of fish and tend to be found in groups. They get their name from the fact that they seem to ‘grow’ from the floor of the ocean and when many are seen together they resemble plants in a garden.
Probably the best-known eel in the world – at least by reputation – the Electric eel (Electrophorus electricus) isn’t actually an eel at all; it is a species of knifefish and more closely related to the catfish and carp than to any species of eel. Electric eels are freshwater fish exclusive to South America, where they inhabit the Amazon and Orinoco river basins, swamps, creeks, and smaller rivers. They will usually be brown or dark grey with yellow or orange undersides; have an eel-like shape; grow to between 6 and 7 feet long; and weigh between 40 and 50 pounds when adult. As their name indicates, the Electric eel is capable of producing electrical charges of between 600 and 700 volts (comparable to TASER) that they use to stun prey – which usually consists of invertebrates, other fish, and small mammals such as rats. Contrary to myth, generally speaking, the shock from an Electric eel will not be strong enough to kill a healthy adult human, but it will certainly hurt like hell! The Electric eel is an ‘obligate air-breather’, meaning that it must rise above the surface every ten minutes or so to breathe. The lifespan of the Electric eel in the wild is believed to be between 15 and 20 years.
Lisa has a Bachelor’s of Science in Communication Arts. She is an experienced blogger who enjoys researching interesting facts, ideas, products, and other compelling concepts. In addition to writing, she likes photography and Photoshop.