There’s a lot of mixed opinions about eels – some of us love them, others could do without these bottom feeders that could leave a nasty bite with their surprisingly sharp teeth.
There’s a lot we have learned about eels over the years, including how they use their strong teeth to their advantage when feeding and what to do in the rare case an eel bites you.
Eels With Teeth
There are over 800 eel species, varying in color and ranging in size from 2 inches up to 13 feet, and most of them have teeth. The longer and larger the eel, the more teeth they have for successful underwater hunting. Their teeth may look small compared to the rest of their bodies, but they are mighty and can do a lot of damage. Some eels even have two sets of teeth.
Moray Eel
You can tell moray eels apart from others by their second line of teeth. Their threatening teeth can be 2 cm long and make these apex predators practically impossible to escape from.
Not only are they adept at hiding near the ocean floor as they wait for prey, but most importantly, moray eels have a second set of jaws called pharyngeal jaws. Jagged, tough teeth allow moray eels to secure and swallow their prey.
Moray eels live in coral reefs of warm, tropical waters and as far north as New Jersey in the western Atlantic Ocean, where they use their teeth to hunt for squid and cuttlefish. In addition to pharyngeal jaws, California moray eels have jagged teeth on the top of their mouth to effectively trap squid and fish on all sides.
Electric Eel
Another predator is the electric eel, which is a type of knifefish more closely related to carp and catfish. Electric eels don’t actually have teeth, but rather bumpy, bulbous mouths that send electrical currents through to their prey.
Electric eels don’t need teeth because they can generate as much as 800 volts of electricity through the inside of their mouth as they force, shock, and choke their next meal.
Instead of biting down hard with their teeth like other eels, electric eels form a C shape around their prey and render them unconscious via electric shock.
By shocking prey into submission, electric eels can feast on small fish, crustaceans, vertebrates, and insects, swallowing them whole. Juveniles eat invertebrates like shrimp and crabs, while freshly hatched electric eels are known to feed on the leftover unhatched eggs.
Electric eel bites and attacks on humans are very rare, as they are found in remote regions of the Amazon and Orinoco rivers. For adventurers who do end up with one on their line, it’s crucial to avoid unhooking the eel with bare hands. Rubber gloves can help shield the inevitable electrical shock from inside their fierce, toothless mouths.
Freshwater Eel
One of the most common eel species found in the U.S. is the American freshwater eel, which has movable jaws with small but damaging teeth to crush their prey. Freshwater eels range from 20 to 60 inches as full-grown adults, with long, conical heads and short jaws containing several series of narrow teeth close together. They also have tiny teeth in their throat.
Freshwater eels come out at night along the Atlantic Coast and rivers to feed on small fish, crustaceans, clams, mollusks, and worms. Brine shrimp and bloodworms are some of their favorites, as they are easy to swallow and digest even with their short, small teeth.
While their jaws aren’t as strong as other eels, freshwater eels have adopted a unique feeding process for prey that’s too big to eat whole. If the eel can’t break the prey into pieces by pulling or jerking, then they can clamp their teeth down hard and spin their bodies to generate enough force to break it apart. Some adult eels can do as many as 14 spins per second.
Conger Eel
Conger eels are some of the largest eels, reaching up to 6 feet with pointed mouths and crowded rows of sharp triangular teeth. These bottom feeders live in the Atlantic Ocean off North America and Europe, where they feed on fish, cuttlefish, squid, octopus, crayfish, lobster, shrimp, and prawns.
Conger eels swim close to the ground in search of prey they can grab hold of in their wide mouths. They have more teeth toward the front and in the roof of their mouths to help with the initial ambush, so these opportunistic predators quickly subdue their prey.
Not only do conger eels lurk near rocks and coral, waiting for small fish and crustaceans to break down with their numerous teeth, but they also scavenge for dead, rotting fish. As congers age and reach around 15 years old, they undergo a transformation with their reproductive organs increasing, but their teeth fall out and their skeleton shrinks.
Do Eels Have Pharyngeal Jaws?
Most eels have just one set of jaws, but moray eels are unique in that they have a second separate set of jaws in their throat to help them feast on fish, squid, cuttlefish, and crabs. Armed with the unique advantage of two jaws, moray eels almost always fatally ambush their unsuspecting prey.
So how do these pharyngeal jaws work? Essentially, the moray eel seizes its prey in its first pair of jaws inside the oral cavity. These jaws have piercing teeth that curve back toward the throat.
Using these teeth, moray eels push prey downward and stop smaller fish and crabs from wiggling out of the eel’s mouth, similar to spike-strips in parking garages.
When the eel has a firm hold on its prey, its pharyngeal jaws come forward, snatching the prey and bringing it down to the esophagus to be swallowed. Pharyngeal jaws are supported by flexible muscles that allow them to spring forward and grab hold of the prey to finish the feast.
Why Do Eels Have So Many Teeth?
The short and simple answer to the large number of eel teeth is that they help them hunt, eat, and survive. As carnivores, eels feast on worms, snails, shrimp, mussels, frogs, lizards, and small fish.
The larger eel varieties are usually big predators in their habitats, preying on feeder fish like minnows and guppies with their wide mouths and tough teeth.
Eels need razor-sharp teeth to capture their prey and eat it quickly. With their long bodies, they must hunt and eat efficiently to keep their spot in the food chain and stop small fish and crustaceans from escaping their grasp.
Do Eels Bite Humans?
Most eels will only bite humans when they feel threatened, so just know what to look out for when swimming or fishing. If you do your best to avoid eels and respect their territory as much as possible, the chances of an eel bite are quite slim.
One of the few times when eels may bite is if they are stuck on a fishing line and you’re trying to free them. Otherwise, rare eel bite incidents in the ocean are usually the suspected result of mistaken identity, when hunting eels confuse a reflective wetsuit or scuba gear as a small fish.
What to Do If an Eel Bites You?
If you get bitten by an eel unexpectedly, whether you’re fishing, swimming, or scuba diving, there are a few things you can do to remedy the pain.
First things first, look out for the obvious signs of an eel bite, like immediate pain, puncture/bite marks, cuts, swelling, and numbness.
Next, follow these steps to ensure a safe and speedy recovery after an eel bite:
- Wash superficial wounds right away with warm water and soap.
- Apply pressure to calm the bleeding.
- Put on antibacterial ointment and a sterile bandage.
- If you’re in pain, try an at-home reliever like Tylenol or Advil.
- Call a doctor if pain persists or the bite seems severe.
Conclusion
Eels may resemble snakes, but these ray-finned fish are flatter and longer, with a mouthful of sharp teeth to watch out for. Strong teeth and sturdy jaws help eels capture and chew their prey.
Whether you are fishing in the tropics or headed to your local freshwater fishing spot a little closer to home, you can expect to encounter eels at some stage. Eel bites are rare, but just make sure you watch out for their sharp teeth and take precautions if you do suffer a bite.
References
https://oceanconservancy.org/blog/2019/07/09/difference-between-electric-eels
https://www.npr.org/templates/story/story.php?storyId=14194579