5 Most Famous Species Of Saltwater Aquarium Worms

Last Updated on October 24, 2022 by Griselda M.

Want to learn how to distinguish the most common types of saltwater aquarium worms? Stay with us and find out.

As much as it is fun, keeping aquatic pets can have some disturbing sides. For example, you have just discovered some tiny creatures crawling or floating in your aquarium tank. However, you don’t need to panic; most of them are actually completely harmless. Nevertheless, that’s not always the case so sometimes you’ll have to reach for some infestation solution.

To know who you are dealing with, you need to identify the “enemy”. So today we are going to talk about saltwater aquarium worms. Keep reading to find out all the details about these frequent visitors to our aquariums.

What Are Aquarium Worms?

Many hobbyists are confused or frightened when they see a long string coming from their fish’s anus. It is not an aquarium worm, but a classic gastrointestinal secretion, it is completely normal and is no cause for alarm.

how to get rid of tube worms in salt water aquarium?

On the other hand, saltwater aquarium worms can be either parasitic or commensal, and internal or external. The task of parasitic worms is unique and focused only on them, to the detriment of the resources of their hosts.

Types Of Saltwater Aquarium Worms

Read more about each type below and find out what you are dealing with.

Feather Dusters

– Not harmful

Feather Dusters are a type of saltwater aquarium worms that are known for their highly branched fan of tentacles that extends from their tubes, and they look like feather dusters. Some of the most famous species of feather duster worms are the Hawaiian feather duster worm, red, yellow, purple, or orange feather duster worm, giant, dwarf, or mega feather duster worm, and social feather duster worm.

It is most often found in the subtidal zones of reefs around the world, positioned in moderate currents because only such conditions will not damage their feathery crown. Interestingly, these saltwater aquarium worms don’t have a face and eyes, but they can detect changes in light. This light sensitivity protects them from predators.

As for the conditions in aquarium tanks, they are not particularly picky but prefer standard reef tank water parameters. Note that they are particularly sensitive to copper.

 saltwater aquarium worms

Leopard Polyclad Flatworm

– Harmful

If you notice them in your aquarium – it’s time to take action! They come in a range of colors, and threat levels, but are known as real pests because they tend to eat your snails and clams.

They are quite easy to eliminate as their diet is quite limited. The good thing is that if you have no snails or clams left in your system, the Leopard Polyclad Flatworms will eventually starve and die. In addition, it can be incredibly resilient and resourceful, so the starvation process can take up to several months.

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Peanut Worm

– Not harmful

It is not difficult to assume that these saltwater aquarium worms got their name from the alleged resemblance to a shelled peanut. They have a wide natural range and are found in many of the world’s oceans, most commonly in the shallows.

They usually bury themselves in the substrate, with the bulbous end of the body securely hidden. It won not be so easy to spot them in your aquarium, as they will be buried in the substrate or rock crevices, but you will be able to see the mouth end and their tentacles sticking out first.

Peanut worms are considered beneficial, as they don’t reproduce quickly or bother anyone. They are known to tend to clean the pieces left behind by other creatures, but also aerate the substrate with their digging around.

 What are the worms in my saltwater tank?

Bristle Worm


Bristle worms are the most famous and widespread group of saltwater aquarium worms. They are recognizable by their segmented bodies with bristle-like protrusions — called chaetae — along their sides.

They usually go unnoticed unless you look for them at night with a flashlight or expose them in some other way like moving a rock or displacing the substrate. Most of them are not harmful they are considered beneficial. However, those that are not can overrun the entire tank and cause irritation as well as many other problems for your aquatic pets.

Getting rid of bristle worms can be difficult and time-consuming, but it is very possible.

Black worms

– Caution

Black worms are among the best foods that you can feed your fish because they are rich in protein and nutrients as well as many other components essential to the growth and development of your pets. However, keep in mind that there are some species of saltwater aquarium worms that belong to the group of Black Worms and are very harmful. Some live as parasites in fish’s bodies, thus inflicting damage one way or another.

Harmless species are Drain fly larvae, Blood worms, Mosquito Larvae, and Leeches.

Harmful species are Planaria, Anchor, and Camallanus worms.

Although they are all black, as the name suggests, it is not difficult to distinguish them. The only tools you may need are a magnifying glass or a microscopic camera. In addition, you can distinguish them by their movement. Those who swim freely are harmless and an excellent food source for your fish. Unlike them, those that attach themselves to the fish are harmful and can be deadly for your fish.


To Wrap Things Up

Having an aquarium in most cases means researching what is normal versus what is abnormal. The hardest part is that it’s not really that easy to tell. Among all the challenges, worms certainly stand out.

That’s why we’ve taught you to distinguish 5 saltwater aquarium worms. Have you ever met them in your aquarium tank? Let us know in the section below.

You may also be interested in Your Ultimate Guide To Saltwater Aquarium Filter Types


What Causes Tiny Worms In A Salt Water Aquarium?

The most common reasons for the expansion of tiny worms in your aquarium are uneaten food, detritus, and carrion.

How To Get Rid Of Tube Worms In Saltwater Aquarium?

Among all the methods for removing this type of worm, the introduction of some worms-eating species certainly stands out. Some of them are wrasses and flame hawkfish.

What Will Eat Bristle Worms Is Salt Water Aquarium?

These are the most commonly used aquarium fish that eat Bristle worms:

Six line wrasse,

Flame hawkfish,

Longnose hawkfish,

Melanurus wrasse,

Neon dottyback,

Orchid dottyback,


Are Worms Good For Aquariums?

There are “good” and “bad” types of worms. Some are completely safe to keep in an aquarium because they are a great source of food for your pets (rich in protein and nutrients). On the other hand, there are those “bad” types that you would never want to keep near your aquatic pets because they are parasites. They are prone to attachment to fish and are therefore harmful and very deadly.