Feather Duster worms are one of the star attractions in any mature reef aquarium and a welcome hitchhiker that may come as a surprise when buying uncured live rock. These delicate looking worms offer a wonderfully textured contrast to the hard edges of corals and gelatinous anemones.
While they do need some extra attention Feather Duster worms aren’t too challenging to keep. So long as you can meet their water quality, feeding, and tank mate requirements you will likely enjoy one (or many) for years to come!
What are Feather Duster Worms?
Believe it or not, Feather Duster worms are the saltwater cousins of the familiar garden earthworm!
Both worms are in the Annelid phylum, which includes most segmented worms. Leeches, Bristleworms, and Tubifex worms are also annelids and a close look reveals they have the same segmentation as the rest.
It’s hard to make the connection with Feather Duster worms though because they spend all of their time locked away inside their homes. Instead of hunting around for food they prefer to find a spot with ideal currents and then let food come to them.
All Feather Duster worms (as well as the closely related Christmas Tree worms) are filter feeders. They extend their radioles (which do double duty as gills) to pluck out floating bits of food that waft by. This includes everything from bacteria to plankton.
The worm then sifts through the mucus-covered bycatch, choosing the tastiest bits, and then discards the rest while pushing food towards its mouth. Each radiole is covered in microscopic hairs called cilia that push the food particles through the slime. Gross but highly effective!
Most of these worms have the ability to leave their tubes if necessary but only do so if stressed, attacked, or in need of a better location. Exposed, they are a tempting meal for just about any passing animal.
While they have neither a face nor eyes they are still tremendously sensitive to light, motion, and currents. If anything gets too close to their radioles they can retract them in an eyeblink. Many species also have a hard operculum (lid) to block the entrance of their tubes.
Now that we know what Feather Duster worms are like let’s talk about caring for them.
- Common Names: Feather Duster Worm, Fan Worm
- Scientific Name: Sabellastarte sp., Bispira sp., suborder Sabellida
- Origin: Worldwide
- Diameter: 3-6 inches
- Aquarium Size: Any
- Temperament: Peaceful
- Ease of Care: Moderate
Caring for Feather Duster Worms
There are two main types of Feather Duster worms: sabellids and serpulids. The sabellid worms create tubes out of sand, muck, and bits of rubble. Using their mucus as handy glue they can construct a tube in just a few hours.
Sabellid worms are much more likely to leave their tubes considering how fast they can build a new one. When transporting a sabellid worm to a new home they may also opt to leave their tube.
New aquarists may think their worm has died. Instead, you can simply place the worm in your tank on the substrate or in a shallow pan of aquarium water and sand. The worm will likely start on a new tube quickly and can then be introduced into its new home once its finished.
Serpulid Feather Duster worms create hard calcareous tubes. They are typically found dug into hard surfaces like live rock and corals. Serpulid worms secrete acids to establish themselves in their new home.
And since they often burrow right into living corals, as the corals grow the Feather Duster worm’s tube grows in length with their hosts. Serpulid Feather Dusters are also believed to feed on the mucus of their host coral.
Aquarium Size
Feather Duster worms don’t swim freely and aren’t at all picky when it comes to aquarium size. They can thrive in any sized tank so long as they have enough space to spread their radioles out and feed.
Smaller tanks can make it easier for them to feed unless you’re target feeding your worm with a syringe. On the other hand they will consume all of the microorganisms in a smaller tank much more quickly.
I recommend keeping larger worms in medium to large aquariums where they have enough room to really showcase their beauty. There will also be that much more food available for them. Aquarium maturity is much more important than size.
Water Quality
Like most marine invertebrates Feather Duster worms require high quality water conditions. This means very low to undetectable levels of nitrogenous wastes (ammonia, nitrite, and nitrate).
Unfortunately, the feeding habits of Feather Duster worms complicates this quite a bit. As filter feeders they require a stream of food particles suspended in the water column. Inevitably a lot of this food will go to waste, potentially fouling the water if other organisms don’t consume it.
Keeping Feather Duster worms with other filter feeders like crinoids, corals, and sponges helps ensure any mess is swept up. You should definitely be running a protein skimmer or refugium in any tank with Feather Duster worms as well. Otherwise leftover food will decay into ammonia, release phosphorus, and contribute to algae spikes and poor water quality.
That said, some species of Feather Duster worms are less sensitive than others. Most of the smaller species that hitchhike via live rock are often very tolerant of poor quality water. They can even live in sumps and refugiums, picking out detritus from the water column that gets swept in.
Fluctuations in water parameters, even within safe levels, may cause the worm to either leave its tube or shed its radioles. When this happens an inexperienced aquarist may come to think the worm has died. But this isn’t always the case.
Feather Duster worms can regenerate their radioles. Within a couple of weeks, the worm will re-extend its new radioles if it hasn’t died. So it’s better to wait and see if you see discarded radioles near the tube.
Like all invertebrates Feather Duster worms are highly sensitive to dissolved medications like fish parasitic treatments. These agents often include copper or are copper compounds, which will kill any invertebrates, including the ones you want.
It’s always best to treat sick animals in a separate quarantine tank if you have a reef aquarium. Because with so many different animals you can never be 100% sure about any one treatment.
Feeding Feather Duster Worms
As mentioned earlier Feather Duster worms are filter feeders. They use their wafting radioles to pluck out fine particles from the water column. These worms are actually quite selective! They have grooves within their cilia that help them sort out particles by size.
Large bits like sand won’t make it within the grooves. Smaller particles like phytoplankton, bacteria, rotifers, and zooplankton will fit fully within. These microscopic prey get shifted towards the mouth.
Since Feather Duster worms prefer microscopic live food they do best in mature aquariums that already have healthy populations of microorganisms.
It’s a good idea to add a Feather Duster worm to your tank once it’s been up and running anywhere from 6 months to 1 year. Newer tanks simply don’t have enough microorganisms to keep one fed. You may have difficulty keeping a feather duster worm healthy in reef tanks with ultra pure water as well.
If you intend to feed your worm personally, your best bet is to culture infusoria. Infusoria is a catch-all term for paramecium, amoeba, and other single celled organisms that live in the water column. With an infusoria culture you can give the worms a light dusting several times a week.
Some aquarists advocate offering larger particles, like powdered flake and brine shrimp nauplii. You’ll see mixed levels of success doing so as this depends primarily on the Feather Duster worm in question.
Larger species like Giant Feather Dusters can handle particles as large as brine shrimp nauplii. But most types of Feather Duster worm strongly prefer micro organisms for food.
Green water algae and rotifer cultures are another ready source of food. If you don’t want to do the work of culturing it yourself, phytoplankton and zooplankton are easily found bottled nowadays.
If you keep your Feather Dusters in a species-only or fish tank free of corals and other sensitive animals you can simply flood the water column with food. Living plankton will live for days, providing a constant source for the worms.
If you are a reef keeper you should instead provide targeted feedings to your worms using a pipette or syringe a couple times per week. When the worm has its radioles extended gently release food above the worm.
A strong current may cause the worm to retract; it takes a gentle touch. It’s even better if you can release food upstream so it wafts onto the worm.
Tank Mates for Feather Duster Worms
When choosing tank mates you should stick to fish that are considered reef-safe. Reef safe fish aren’t known for picking at sessile organisms like corals, anemones, sponges, and Feather Duster worms.
Reef safe fish include Ocellaris Clownfish, Neon Gobies, Dwarf LionFish, Mandarin Gobies, Basslets (Chalk, Swissguard, and the Royal Gramma are popular), and Chromis/Chrysiptera sp. Damselfish. I would avoid the larger and more aggressive Clownfish and Damselfish as they may decide to pluck at your worms.
Corals, anemones, sponges, and other sessile invertebrates are by far the best tank mates since they won’t try to eat your worms. Just be mindful of the feeding requirements of Feather Duster worms. Leftover floating food can make keeping the water parameters ideal for sensitive corals challenging.
You can also keep feather duster worms in colonies with one another. Some, such as the Social Feather Duster (Bispira brunnea) tend to form groups on their own.
Many popular saltwater fish are not good tank mates for Feather Duster worms. This includes most grazing fish and invertebrate predators such as Puffer fish, Triggerfish, Saltwater Angelfish, and Wrasses. Butterflyfish and Hawkfish also love eating these worms, using their long snouts to pluck them right out of their seemingly secure tubes.
Most invertebrates are going to be safe with Feather Duster worms so long as they are reef safe. But you should watch out for the more aggressive opportunists, especially medium to large crabs.
Crabs can use their claws to snip off the extended radioles. Some may even try to break right into the tube, especially soft tubed species like Giant Feather Dusters.
Good Tank Mates for Feather Duster Worms:
- Ocellaris Clownfish, Gobies, Basslets, smaller Damselfish, and other Reef-safe fish
- Blood Red Fire Shrimp, Cleaner Shrimp, Sexy Shrimp, and other peaceful shrimp
- Soft and Hard Corals, Anemones, Sponges, Snails, small Hermit Crabs, and other peaceful invertebrates
Poor Tank Mates for Feather Duster Worms:
- Angelfish, Triggerfish, Wrasses, Puffer Fish, Butterflyfish, and other invertebrate-eaters
- Large Crabs and Shrimp
- Starfish
Breeding Feather Duster Worms
Feather Duster worm breeding is typically a happy accident rather than a planned event. The worms can be fairly temperamental and they are impossible to sex by looking. These worms are known as broadcast spawners, which is very common among sessile reef organisms.
When the conditions are right, the worms will spawn in sync with each other, releasing clouds of eggs and sperm into the water column. The gametes meet by chance and the fertilized eggs form part of the planktonic cloud that wafts about the reef.
The eggs will hatch within days and the larvae feed on other planktonic organisms before settling to the substrate and forming their own tubes and radioles. They appear as miniature adults that are always a delightful surprise.
Since aquarium filters are efficient at screening out the gametes from the water column you may miss out on the spawning event, which takes place during the evening or at night.
Serpulid (hard tube) Feather Duster worms reproduce entirely sexually. But Sabellids (soft shelled) worms occasionally reproduce asexually as well. The worm will lose a portion of their rear body in a process called scissiparity.
The lost segments then form into a brand new worm that builds a tube and grows radioles. This new worm is a genetic clone of its parents. Both sexual and asexual reproduction have their advantages.
Sexually reproduction ensures that new genetic material is encountered, raising the possibility of helpful adaptations being discovered.
But asexual reproduction is a competitive advantage if there are no mates around, such as when a brand new habitat is discovered. Or if you’re a worm that can’t move to find a mate!
