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Are Spirorbid Worms Good Or Bad?

As the number of people getting involved in fish keeping continues to increase, we have noticed more and more questions from the fish keeping community about the various types of parasite that you can have problems with in your tank.

We have noticed a large number of questions about spirorbid worms recently with something as simply as a spirorbid worms being surprisingly controversial within the fish keeping world.

Although we do see a number of different questions about spirorbid worms, the majority of them tend to boil down to asking if spirorbid worms are good or bad.

The reasons that spirorbid worms are so controversial within the fish keeping community is that the actual answer will depend on you, your goals for your tank, and how often you perform tank maintenance on your tank.

This is why we wanted to publish our own dedicated article going over the various ins and outs on spirorbid worms to try and help as many of our readers as possible.

Our hope is that we will be able to present the argument from both sides and help our readers better understand if they should leave spirorbid worms in their aquarium or try to remove them.

Are Spirorbid Worms Good Or Bad?

Spirorbid worms are generally considered good for an aquarium as they are filter feeders and will pull tiny impurities from the water of your tank and feed on it.

This can help to reduce the need for tank maintenance with spirorbid worms also being able to filter out algae spores and fine detritus too.

The issue with spirorbid worms is that they are generally unsightly with many fish keepers considering them ugly as they form on almost any surface in your tank with their signature white spiral ring.

This can be an eye sore and totally ruin a display tank or a carefully created aquascape with the eye usually being naturally drawn to the tiny white spirals all over the tank rather than its beauty.

This is why many fish keepers will say that spirorbid worms are bad and should be removed from your tank.

If you don’t care about the aesthetic element of your tank then you are generally fine to leave spirorbid worms in your aquarium though with many fish keepers leaving them in to filter their tanks water as they feed without issue.

“Spirorbid worms” by Derek Keats is licensed under CC BY 2.0. To view a copy of this license, visit

Will Spirordid Worms Harm Your Fish?

Spirorbid worms are generally harmless and will not cause your fish any problems for the most part.

They generally mount to an inert surface and simply stage there filter-feeding and drawing tiny impurities from your tanks water without really paying your fish, snails, or shrimp any real attention.

Some fish will actually feed on spirorbid worms with smaller wrasse being notorious for feasting on any spirorbid worms in your tank but various other fish species will also eat them too.

Spirorbid worms are not toxic and don’t sting your fish either so it is usually fine to leave them in your tank as a potential food source for your fish source too.

We have seen some people claim that spirorbid worms have attacked fish eggs in their aquariums but we doubt that this is true as spirorbid worms don’t eat fish eggs.

Our guess is that a fish has laid its eggs on a spirorbid worm and the presume from the egg laying on the worm has forced it inside of the egg making it look like it is trying to feed on the egg when in actual fact, the spirorbid worm was just minding its own business.

Where Do Spirorbid Worms Come From?

Spirorbid worms are commonly added to aquariums by accident due to their eggs being in new substrate or on new rocks or live plants that you choose to add to your aquarium.

Once a group of spirorbid worms have found their way into your tank, they can spread at a surprisingly rapid pace.

This is why it can sometimes appear that a huge number of spirorbid worms suddenly found their way into your tank but in actual fact, there was probably a hand full of worms that were accidentally added and then they reproduced.

The baby spirorbid worms were tiny and difficult to see for the first week or so and then they grew to a size where you were able to see them all.

Some fish keepers do sometimes get taken a back by this but it is usually nothing to worry about. It can be a bit of a pain to fully remove spirorbid worms from your tank with a dip usually being the best method depending on your tank set up and the rest of the tank mates.

As we mentioned above though, some smaller fish will see spirorbid worms as a potential food source and help you to control their population while boosting the nutrients in the diet of your fish too.


That brings our article going over if spirorbid worms are good or bad to an end. We hope that we have been able to help you better understand why spirorbid worms are considered controversial but it comes down to your goals for your tank. From a purely practical standpoint, spirorbid worms are good for your tank as they help to remove impurities from your water. From an aesthetic standpoint, spirorbid worms are considered bad for your tank due to being such an eye sore, especially in large numbers and drawing your eye away from the rest of your tank.