Eels vs Jawless Fishes(Lampreys): All Differences Explained

morray eel vs jawless fishes


An animal kingdom is a complex group of creatures with different traits and adaptive behaviors; They can be quite different yet strikingly similar. It is quite common to encounter entirely different species sharing the same physical characteristics. Among insects and reptiles, for example, species that belong to the lower tiers of the food chain would adopt the traits of their predators to protect them from being hunted. Of course, there are other evolutionary and biological reasons for such a phenomenon.

Eels and jawless fishes illustrate how two completely different animals may share the same overt traits. At first glance, one would have a difficult time distinguishing eels and sea snakes. Both have elongated and slim bodies. Both have serpentine qualities. In addition, they tend to share the same habitat. But eels and sea snakes are completely different.

This article will go through some of the differences between eels and a representative of the jawless fishes: the lamprey.


Eels are physically recognizable due to their snakelike bodies and movement. On average, a mature eel can reach 70 cm in length. The American eel is approximately 50 cm long. In comparison, the European eel can reach a maximum length of 80 cm. The short-finned eel is about 90 cm long. Finally, the Japanese eel can be as long as 100 cm. Depending on the variety, eels can be between 1 ounce to 55 pounds in weight.

Lampreys also share the same snakelike qualities as the eels, But they can grow to exceed eels. A mature lamprey can grow somewhere between 12 cm to a maximum of 100 cm. But they are light that they barely weigh a pound.


Although there are some pronounced differences between and among eel species, they generally share the same flattened shape compared to the cylindrical bodies of sea snakes. Eels have smaller scales that contribute to their smooth and sleek appearance. Most eel varieties have a drab or gray color that allows them to blend well with water environments. Eels resemble flexible swords cutting through the water. Their heads are more elongated and sharp. Because eels are fishes, they also have fins. These fins run from the back of their heads and run across the back. They also have fins on the bottom part of their bodies.

eel vs lamprey

Lampreys resemble eels closely that they have been mistakenly referred to as lamprey eels. They have snake-like bodies. But while eels have flat bodies, lampreys are partially cylindrical, particularly in the mouth and head. Unlike eels, lampreys are cartilaginous fishes. The lamprey’s most striking feature, however, is its jawless mouth designed for suction. The mouth of a lamprey is circular and filled with inward-pointing rows and columns of teeth to latch on to its prey.

lamprey vs eel


Eels thrive in both freshwater and saltwater environments. They can be found in shallow streams, silted rivers, marine estuaries, and coastlines. Most eels are catadromous, meaning they seasonally migrate from upland freshwater down to seas and oceans. Since eels are bottom feeders, they make their homes in enclosed spaces such as rock caves, plant masses, mud tunnels, and other similar shelters. During the colder months, they tend to retreat under the mud and hibernate.

Lampreys can be found in marine and freshwater environments. They live mostly near the coastlines of temperate regions. Lampreys are distributed around the world except in Africa. Unlike eels, lampreys are anadromous. This means that they migrate from the oceans to upland rivers to breed. Non-carnivorous and non-parasitic lampreys are mostly bottom feeders that scrape off algae from rocks.


Eels are predominantly nocturnal predators who rely mostly on their keen sense of smell. The rich ecosystem in freshwaters and marine waters provides them with an abundant source of food. Eels feed on small fish, frogs, snails, small crustaceans, insect larvae, and worms. Interestingly, they tend to eat only twice or three times a week.

There are two general types of lampreys in terms of diet. The carnivorous type is parasitic and feeds on the blood of other animals. They latch on to the bodies of their prey with their teeth and suck the blood. Most of the fishes they parasitize are sharks, whales, herring, and trout. They do not attack humans unless they are starving. This blood-based diet is referred to as “hematophagy”. There is another type of lamprey that does not feed at all. As a larva, they filter-feed. When they reach maturity, they do not feed. Instead, they merely rely on their energy reserves to get them through the breeding stage. They die soon after.


Eels are not venomous. They can be very aggressive when they feel harassed. But when they are threatened, they can deliver a nasty bite. The moray eel is relatively dealt with caution because it possesses a powerful set of jaws and rows of sharp jagged teeth, which it utilizes to restrain prey and deliver a very painful bite.

Lampreys are simple creatures. Their entire life is all about latching on to a healthy host to feed on it until it dies and then migrates to freshwater areas to breed. The non-carnivorous species do not even bother to abandon their breeding spaces. They spend most of their lives feeding larvae. Then, they develop briefly into breeding adults whose single purpose is to spawn and then die.


Eels are sometimes kept as aquarium pets. But it’s quite difficult, expensive, and time-consuming to care for an eel. They tend to be very picky about their living arrangements. If they are not content with the size of their tanks, they become quite reclusive. They may even refuse to feed. The eel that is captured in the wild or farmed in a semi-wild setup is processed as food. American eels are smoked or grilled. They are valued for their flavorful and clean-tasting meat.

Lampreys have a double-edged relationship with humans. In some parts of the world, particularly Europe and Asia, They are highly prized for their rich and tasty texture. Lampreys are considered delicacies in these areas. But in the United States, they have become a pest. They were introduced into North America as an invasive species that severely impacted game fish such as the trout. For fishing communities and industries, this has become a significant economic issue.


Eels evolved some 3.5 million years ago. The ancestors of the modern-day eels can be traced back to the Eocene period. The point of origin for eels is believed to be in the western regions of the Pacific Ocean.

Lampreys, together with the hagfish, are an ancient species. They evolved into a distinct species some 450 million years ago. They are the only extant representatives of the jawless fishes which have gone extinct. Their lack of jaws is an indicator that they diverged early and long before appendages evolved among vertebrates.



Yes. Eels are standard fixtures in Japanese cuisine, where they are referred to as “unagi”. Their oiliness and fat content are sought after. Eels are also very popular in Chinese cuisine. Unlike other fish, which may be served raw as sushi or sashimi, eel is always cooked. This is because the eel’s blood is toxic and requires proper preparation and cooking to neutralize in the United States and Europe. Eel is considered a delicacy. They are rinsed and scraped to rid them of their sliminess. Then they are rinsed thoroughly and dried for about two hours; They are frequently served grilled. Eels are also smoked for about three hours to enhance their fishy flavor and aroma.


Yes. Lamprey meat was a staple among the ancient Romans and the Christians during the Medieval Ages. They were a popular food choice among the nobility, particularly during Lent. It is said that lampreys were valued because they had the same general texture and taste as game meat. Today, they are treated as delicacies in such countries as Portugal and Japan. It is essential that they are cleaned and processed because they may contain toxins.


No. Aside from extreme discomfort, a blood-sucking lamprey will not kill a human immediately. It is more possible to die from a lamprey bite wound that gets infected. It is relatively easy to get rid of a latched lamprey. You just need to get out of the water, and the lamprey will let go because of suffocation.


No. Electric eels may look like eels, but they are more related to catfish. There are no electric eels in seas and oceans; Their habitat is mainly confined to the forest rivers and freshwaters of South America. Mature eels can generate about 600 volts of electricity, But even though this can be very painful, there are very few casualties due to electrocution. Deaths attributed to electric eels are primarily due to cardiac arrests caused by the shock of the encounter or drowning due to being incapacitated by the electric shock.