Bristleworms are a unique underwater species. Many bristleworms inhabit self-made cylindrical tubes made of sand and detritus while extending their feeding tentacles outwards, usually no longer than their body length.
These fascinating creatures can grow up to 33.5 mm in length, with their tubes reaching over 60 mm long and 3 mm wide.
These worms are often found in marine environments and play an important role in the underwater ecosystem.
They act as both scavengers and predators, helping to maintain a balanced food chain. Additionally, their burrowing behavior helps aerate the ocean floor, benefiting other organisms that inhabit the same area.
While bristle worms can be a fascinating topic for marine enthusiasts, it is essential to handle them with care when encountered in their natural habitat.
Their bristles, or chaetae, can cause skin irritation when touched. So, if you go exploring in their marine environment, make sure to admire them from a safe distance.
Bristle Worm Basics
Bristle worms, or polychaetes, are a type of segmented worm found in marine environments.
They can be red, green, yellow, or brown colored when alive and can be up to 33.5 mm in length.
Some of them have tube-like homes over 60 mm long and 3 mm wide1.
Segmented Worms Classification
Bristle worms belong to the Polychaeta class, which is a part of the Annelida phylum.
The term “polychaete” comes from the Latin word polychaeta meaning “many hairs,” referring to the bristles on their body.
Segmented worms, or annelids, are classified into three main groups:
- Polychaetes (bristle worms)
- Oligochaetes (earthworms)
- Hirudineans (leeches)
Habitat and Behavior
Many of these worms inhabit self-made cylindrical tubes made of sand or detritus1. However, not all do this – some bristle worms, called Errantia, are mobile and do not build tubes
They are nocturnal creatures, often hiding in crevices during the day and emerging at night to search for food.
Bristleworms use their feeding tentacles to catch prey and scavenge for organic material.
They also have blood vessels within their body segments, forming a circulatory system essential for their survival.
Bristle Worms in Aquariums
Bristle worms are common polychaetes, often found in reef tanks and saltwater aquariums. These creatures are mainly detritus feeders that consume:
- Uneaten fish food
- Decaying organic matter
- Dead algae floating in the tank
They inhabit substrate layers and live rock, keeping the aquarium ecosystem clean by breaking down waste materials.
Bristle worms have a few natural predators in the aquatic world, such as:
- Arrow crabs
Introducing these inhabitants to your fish tank can help control the bristle worm population.
Effect on Coral and Other Inhabitants
While bristle worms are largely beneficial for the ecosystem, they might harm corals, crustaceans, and mollusks in some instances.
Regularly monitoring their population is essential to ensure a balanced environment for your aquarium life.
Hitchhikers and Cleanup Crew
Some bristle worms can be unintentional hitchhikers that arrive on new live rock or coral fragments.
They can be considered part of the aquarium’s cleanup crew, consuming waste materials and excess food particles that might otherwise harm water quality.
In this role, they help maintain a stable aquatic environment for fish and invertebrates.
Dealing with Bristle Worms
Bristle worms can be removed from your aquarium using a pair of tweezers.
This method is effective when you can see the worm and can quickly grab it.
Be cautious, as bristle worms can release toxins or cause stings and burns when mishandled.
Another approach is to employ predators to manage your bristle worm population, as mentioned earlier.
Traps and DIY Solutions
A variety of bristle worm traps can be purchased or crafted by aquarists. Common features of these traps include:
- Bait compartments to lure bristle worms in
- One-way entrance to trap them
DIY solutions are also an option. For example, a simple trap can be made using a small PVC pipe and a bait, like raw shrimp, inside it. The bristle worms crawl in but cannot escape.
To minimize the risk of bristle worm infestations, consider the following tips:
- Avoid overfeeding your fish, as excess food can attract bristle worms
- Regularly inspect live rocks and corals for bristle worm cocoons
- Maintain proper tank hygiene by removing dead or decaying organic material
Handling and Safety Precautions
Bristle worms, especially certain species like fireworms, are equipped with bristles or chaetae that can easily penetrate the skin and cause irritation.
Whether you’re a marine enthusiast, diver, or aquarist, understanding how to safely handle or avoid these creatures is crucial.
Here’s a comprehensive guide on handling and safety precautions:
Wear Protective Gloves:
Always wear thick, protective gloves when you suspect you might come into contact with bristle worms.
This will prevent the bristles from penetrating your skin and causing irritation.
Use Tweezers or Forceps:
If you need to remove a bristle worm from your aquarium or any other environment, use a pair of long tweezers or forceps.
This ensures a safe distance between your hands and the worm.
Avoid Direct Handling:
Unless absolutely necessary, avoid handling bristle worms directly. Even with gloves, it’s best to minimize contact to reduce the risk of irritation or injury.
Wash Hands Thoroughly:
After any interaction with marine environments or aquariums, wash your hands thoroughly with soap and water.
This helps to remove any microscopic bristles or toxins that might be present.
First Aid for Bristle Worm Stings:
If you get stung by a bristle worm, immediately rinse the affected area with vinegar to neutralize any toxins. This can help alleviate pain and reduce swelling.
Remove any visible bristles carefully using tweezers. Ensure you don’t break them during removal.
Apply a cold pack to reduce swelling and pain.
If the irritation persists or if an allergic reaction occurs, seek medical attention immediately.
Educate and Inform:
If you’re diving or snorkeling in areas where bristle worms are prevalent, ensure that everyone in your group is aware of the potential risks and knows how to identify these creatures.
Safe Aquarium Practices:
Regularly inspect your aquarium for any unexpected bristle worm inhabitants.
If you’re introducing new live rocks or corals, quarantine them first and inspect for any hitchhiking worms.
When cleaning or rearranging your aquarium, always be cautious and look out for hidden bristle worms.
Continuously educate yourself about the marine life in your area or in areas you plan to visit.
Knowing which species of bristle worms are prevalent and their habits can help you avoid unwanted encounters.
Bristle Worm Predators
Several fish species prey on bristle worms in marine environments. Some examples include:
- Hawkfish: Known for their hunting prowess, they enjoy munching on bristle worms.
- Butterflyfish: These colorful fish also feed on bristle worms, as well as other small invertebrates.
- Wrasses: The Gomphosus varius, Maori wrasse, Cheilinus oxycephalus, and Sunset wrasse (Thalassoma lutescens) are just a few of the wrasse species that eat bristle worms.
- Dottybacks: These small carnivores feed on bristle worms and other invertebrates.
Bristle worm predators in the crustacean family include:
- Arrow Crabs: With their long legs and pointed snouts, they can easily catch and devour bristle worms.
- Bobbit Worms: These large predatory worms inhabit the ocean floor and feed on bristle worms and other small invertebrates.
- Stenopus hispidus and Stenorhynchus setrcornis: Both crustaceans are known for eating bristle worms and are commonly used as tank cleaners.
Some starfish species prey on bristle worms. A few examples are:
- Asterias rubens: Also known as the common starfish, it has been observed eating bristle worms.
- Luidia clathrata: This starfish species can consume bristle worms as part of its diet.
Various other creatures can also prey on bristle worms, such as:
- Detritivores: Some detritivores, like sea cucumbers, may inadvertently consume bristle worms while feeding on detritus.
- Parasites: Certain parasites, both internal and external, are known to attack and feed on bristle worms.
|Hawkfish||Fish||Effective hunters||Might eat other aquarium inhabitants|
|Butterflyfish||Fish||Colorful addition to an aquarium||Can be picky eaters|
|Wrasses||Fish||Wide variety of species||Some may be aggressive|
|Dottybacks||Fish||Small and agile||Can be territorial|
|Arrow Crabs||Crustacean||Unique appearance||Delicate limbs|
|Bobbit Worms||Worm||Highly effective predators||Can be dangerous to handle|
|Starfish||Echinoderm||Can help control bristle worms||Some may eat corals|
|Detritivores||Misc.||Help clean up detritus||May consume bristle worms by mistake|
Remember that adding these predators to an aquarium can help maintain bristle worm populations, but it’s essential to consider their compatibility with other inhabitants and the overall health of the tank ecosystem.
Bristle worms, marine inhabitants of the Polychaeta class, play a pivotal role in underwater ecosystems.
While they can be beneficial scavengers in aquariums, aiding in waste breakdown and water quality maintenance, some species, like fireworms, can be harmful.
For aquarium enthusiasts, understanding their behavior, natural predators, and management techniques is crucial to maintaining a balanced and healthy tank environment.
Whether you admire them for their ecological role or manage them in your aquarium, bristle worms undeniably contribute to the intricate web of marine life.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about bristle worms. Scroll down to have a look at some of them.
Letter 1 – Bristle Worm
Subject: Imposter from Japan?
Geographic location of the bug: Cannon Beach, Oregon
Time: 12:44 AM EDT
Your letter to the bugman: Found on the beach, November 9, 2018. Was in shallow sea water.
How you want your letter signed: Curious Salemites, Lisa & Steve
Dear Curious Salemites,
We have an image in our archives also from Oregon that we previously tentatively identified as a Marine Worm in the genus Glycera, and this image from APhotoMarine supports that identification.
Update: November 11, 2018
Thanks to a comment from Rusty, we were informed of the common name Bristle Worm. We searched that and found The Chesapeake Bay Program site that indicates Bristle Worms are in the class Polychaeta and this information is provided:
“Bristle worms are soft, segmented worms found along shorelines, mud flats and shallow waters throughout the Chesapeake Bay and its rivers. … Bristle worms have soft, segmented bodies with tiny, hair-like bristles along each side. The bristles are attached to appendages called parapodia. Each body segment has one pair of parapodia, which vary in shape depending on the species. Most worms have a head with eyes, antennae and sensory palps.”
According to Scenic Oregon: “Polychaete worms, of the group Polychaeta, are annelids (segmented worms) that have “legs”– called parapodia– with bristles at the ends. Some polychaetes, especially types of tubeworms, resemble palm trees, with a plume of frond-like appendages at the head.
Of all the species of annelids, the vast majority are polychaetes, with around 10,000 known species. Some common names for different types of polychaetes are bristleworms, clam worms, featherduster worms, fire worms, lugworms, palolo worms, Pompeii worms, sea mice, tubeworms, and many others.
They live underwater in almost every ocean environment, from cold water to undersea volcanic vents, with some burrowing into the sand at the shoreline.”
Letter 2 – Montana Mystery is Jumping Bristletail
insects from Montana desert
September 21, 2009
These are all from roughly the same location in a high-altitude desert in southern Montana. Someone suggested that the first is an antlion larva, even though it doesn’t look like any antlion pictures I’ve found so far.
The second looks almost more like a crustacean than an insect, given the lack of wings and the antenna position. The third looks similar to a damselfly.
south central montana
Your Solpugid and Robber Fly are well represented on our site, but the creature that you believe looks like a Crustacean is a real mystery. We also believe it looks crustacean-like. Its presence on land makes it doubtful that it is a crustacean. We would lean toward an Arachnid, but it really has us baffled.
The clarity of the image is somewhat problematic, as is the texture and tonality of the background which seems to obliterate some of the anatomical details. It also appears like some body parts might be missing.
We will post your letter and image in the hopes that one of our readers can provide an answer. Meanwhile, could you provide any additional information regarding the conditions under which it was found and the size?
Eric Eaton identifies Montana Mystery
Yes, the “Montana Mystery” is a “jumping bristletail,” order Microcoryphia. They are very, very primitive insects. This specimen is missing most (maybe all) its caudal (tail) filaments.