The Shrimp That Cleans the Teeth of Moray Eels

A Dentist… With Claws?

In the coral reefs of tropical oceans, a tiny creature performs a job that seems almost impossible.

It walks fearlessly into the open jaws of predators, dodging sharp teeth that could crush it in a second.

But it doesn’t get eaten.

In fact, the predator lets it do its job — and waits patiently.

Why?

Because this little shrimp is doing a cleaning service.

Meet Lysmata amboinensis, the cleaner shrimp, also known as the Pacific cleaner shrimp or scarlet skunk cleaner shrimp. It lives by crawling into the mouths of big, dangerous fish… and cleaning their teeth.

A Mutual Deal

This is one of the ocean’s best examples of mutualism — where two very different species help each other out.

Here’s the deal:

• The shrimp gets food by eating parasites, dead skin, and food particles stuck between the predator’s teeth.

• The predator gets a free dental cleaning, improving its health.

Both win.

No one gets hurt.

Even more surprising? The predator knows not to eat the shrimp — it waits, opens its mouth, and lets the shrimp work in peace.

How It All Works

The cleaner shrimp doesn’t just clean teeth — it also acts like a spa therapist for fish.

It sets up a “cleaning station” on a coral or rock, waving its long white antennae like a sign that says: “We’re open for business!”

Fish of all kinds — even aggressive predators like moray eels, groupers, and lionfish — line up for their turn. They hover near the shrimp, holding still, sometimes opening their mouths wide.

The shrimp:

• Walks all over the fish’s body

• Picks off parasites with its pincers

• Climbs inside the gills and mouth to clean

• Then jumps off when finished

Sometimes, multiple shrimp work together in shifts — a full underwater cleaning crew.

Risky Business?

At first glance, this looks dangerous.

After all, walking into the mouth of a moray eel isn’t exactly safe.

But Lysmata amboinensis is protected by an invisible contract: if the fish eats the cleaner, it loses the health benefits.

And predators know this. Over time, evolution has shaped their behavior — they’ve learned to tolerate and trust the cleaner shrimp.

If a fish attacks a cleaner, it risks losing access to a valuable service that can:

• Prevent disease

• Improve gill function

• Remove skin parasites

• Help wounds heal

So instead of biting, these hunters become gentle clients.

A Shrimp With a Schedule

Cleaner shrimp are more than just smart — they’re surprisingly organized.

• They prefer cleaning during daylight hours

• They take short rest breaks in crevices

• They return to the same cleaning stations daily

• And they sometimes “groom” each other before starting work

It’s like they clock in and clock out, just like human workers.

Some researchers have even found that cleaner shrimp prioritize bigger fish — giving more attention to clients that bring more food (aka, more parasites).

They know where the value is!

Not Just Fish — Even Other Shrimp

Cleaner shrimp aren’t picky.

They’ve been observed cleaning:

• Moray eels

• Surgeonfish

• Parrotfish
• Groupers

• Even other cleaner shrimp

Sometimes, they engage in social cleaning, where they help clean their own kind — especially during molting, when shrimp shed their old exoskeleton and become vulnerable.

This social behavior strengthens bonds and ensures everyone stays healthy.

Living in Pairs… or Teams

These shrimp are often found in pairs, living in crevices or coral holes.

Sometimes, multiple pairs set up shop in the same area, especially on busy reefs where there’s lots of “dental traffic.”

They’re not territorial, but they defend their space politely — if another cleaner gets too close to a client, they wave their antennae or nudge each other, like saying: “Excuse me, this one’s mine!”

Popular in Aquariums

Because of their unique behavior and bright red-and-white coloration, Lysmata amboinensis is also popular in saltwater aquariums.

Aquarists love them for:

• Their cleaning behavior

• Their peaceful nature

• Their ability to help keep tank mates parasite-free

But in captivity, they still show their natural instincts — setting up stations and trying to clean fish, even if those fish don’t “need” it.

They’ll even try to clean a human hand if you leave it in the water long enough!

A Tiny Hero of the Reef

In an ocean filled with danger, this tiny shrimp does the unthinkable:

• Walks into the jaws of predators

• Delivers a service that keeps the reef healthy

• Maintains relationships built on trust, not fear

Lysmata amboinensis may be small, but its role in the ecosystem is enormous.

Without it, fish populations would suffer — and coral reefs would become more vulnerable to disease.

It’s not just a cleaner.

It’s a healer, a negotiator, and a symbol of cooperation in the wildest place on Earth.