The Difference Between Eels and Sea Snakes

Something slithery this way comes

When exploring the magnificent open waters of the ocean, there are so many creatures and various species to find, some of which are still undiscovered. But some of those we have discovered include eels and sea snakes, two extremely different animals that are often mistaken for one another. But no need to worry, read on and we will guarantee to have you properly prepared for your next encounter with either of these ribbons of the sea.



What They Look Like

Let’s start off with internal and external characteristics that set these two apart and more importantly, how the human eye can spot the main differences.


Eels are a type of fish. Currently, they are classified under the order Anguilliformes with more than 800 different species such as worm eels (family Moringuidae), garden eels (family Congridae), cutthroat eels (family Synaphobranchidae) and, of course, the more Disney-friendly moray eels (family Muraenidae). Since they are a fish, they have gills and live in the water their entire lives. Their fin is singular and continuous, stretching down the dorsal, anal and caudal sides. Eels have elongated bodies with pointed heads, forming a snout and razor-sharp teeth. Although their teeth are not poisonous, there have been suspicions in the scientific community that moray eels produce a toxic slimy coat that creates a higher risk of infection to those who come in contact with them. So if you do find yourself with an accidental eel bite, it would be in your best interest to find a doctor and some antibiotics. Eels can range in size from four inches to 12 feet and are typically a muddy gray or brown tone but can have bright colors and patterns in more tropical areas.


And, before we get to the appearance of sea snakes, we should make a clarifying point about electric eels. Electric eels (Electrophorus electricus) are not eels, but actually part of the knifefish family (Gymnotidae) and more closely related to catfish and carp. Although they look similar to true eels in terms of shape and size, their ability to emit an electrical charge when they feel threatened, or when preparing their next meal, puts them in a classification of their own, like the vampire squid (Vampyroteuthis infernalis). The power they generate is roughly five times the amount of power in a standard wall socket and can have an effect up to eight hours after their death. They can be found in the muddy bottom of rivers and the occasional swamp.

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Now, let’s talk about what a sea snake looks like! Sea snakes are reptiles found under order Squamata and family Hydrophiidae. Unlike eels, there are only about 30-50 different species of sea snakes. The main way to tell sea snakes and eels apart is by their paddle-shaped tail that helps them propel through the water. Since they have lungs, they need to resurface for air, but due to cutaneous respiration, a process in which they breathe oxygen through their skin, they can hold their breath for hours. They are so efficient in preparing for deep dives for food, they can even seal off their nostrils! Their venomous fangs make them one of the deadliest snakes, four times more deadly than the cobra. But fear not, sea snakes are mild tempered and won’t bite unless they feel threatened. And even if they do attack, their short fangs make it difficult to bite through thick fabrics. Their appearance generally consists of dark colors or alternating bands of gray, blue or white.


Where They Live

Depending on what areas you are exploring, you may never even find yourself in the presence of an eel or sea snake, but for the next time you’re planning your vacation to the ocean or diving expedition, here’s some information that may help in choosing your destination.


Eels can be found in both marine and freshwater. They enjoy warmer temperatures and tropical climates, so no worries for our Arctic friends. Eels are bottom-dwellers and usually feel at home in little holes and crevices around coral reefs, rocky areas, and sandy flats. It is said that eels come from North American and European shores to spawn in the waters of the Sargasso Sea since eel larvae are found there, but their migration patterns remain a mystery since there has never been a mature eel spotted in the area.

Just like eels, sea snakes are both marine and freshwater friendly. They also prefer warm temperatures and are typically spotted in the shallow waters of the Indian Ocean and warmer areas of the Pacific Ocean. Since they need air, they usually live in waters less than 30 meters deep and dive down to the seafloor to hunt. Sea kraits (Laticauda) lay eggs on land, nesting on limestones caves and rock crevices; true female sea snakes, however, carry their eggs and then give live birth in the water.


What They Eat

Let’s face it, what we really care about is food and that irrational (but still somehow rational), fear that an eel or sea snake might decide that we’re their next lunch. Hint: They aren’t vegan.

Since eels are found near corals and the ocean floor, their diet consists of a wide variety of sea creatures. They are all carnivorous, subsisting on worms, snails, frogs, shrimp, mussels and lizards. For the larger moray eels, there is an occasional octopus or squid.

Sea snakes have a highly specialized diet. Since they are generally meek, sea snakes thrive on hunting wounded or diseased fish, which promotes a healthy fish population within the coral reef ecosystem. Surprisingly, some sea snakes have been known to include eels in their diet, always swallowing their prey whole.


If all of this was overwhelming: here is a quick snapshot of the key differences between eels and sea snakes!



So the next time you encounter an eel or sea snake, don’t panic. They’re just trying to live their best life.

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