Bad Guys
Bad Guys

First thing to note: These guys are bad guys… If you have one, you need to try and get it out of your tank.

Oenone fulgida, also known as The Orange Worm and Clam Worm, is a predatory marine worm that preys on snails, molluscs and clams. Some aquarists report them predating on LPS polyps too.

Though most Bristleworms (Common Bristleworms) are fairly harmless, this bright orange worm is a different story. Some common Bristleworms will have an orange colour, but the Orange Worm have more of a millipede style leg, and a rounded head, with visible eyes.

Clam Worm
Clam Worm

The first signs of them are normally your snail populations depleting at a faster than usual rate. Other signs will include a jelly like mucus appearing in your rock-work or sand-bed.

The worm uses the clear toxic mucus to stun and smother it’s prey, then devour it slowly. Often, all that remains will be a slime covered shell.

They are very sensitive to light, and as a result of this are a nocturnal species. The only way spotting one would be to use a red light on your aquarium in the early hours of the morning.

How do you control the numbers?

Manual removal with a trap or tweezers is advisable if you have a Clam Worm. You can find purpose built traps at several online vendors, or watch videos on YouTube on how to make a bristle worm trap.

The trap will need to be baited with clams or molluscs, then placed close to where the worm was spotted as they rarely venture out of their cave.

Bristle Worm Trap

Do they have any predators?

The only predator that may predate on some of the smaller specimens of these worms is an Arrow Crab.

Arrow Crab in Reef Tank
Arrow Crab in Reef Tank
  • Arrow Crabs, these are not generally considered reef safe though, and they will not stand a chance against larger examples of Orange worms.

Care should be taken when adding livestock to take care of a pest problem. Once they have eaten all of the pests, they will need supplementing with other foods, or they will need to be re-homed. It is for this reason that using a predator to take care of a pest problem, should be your last resort.

Oenone fulgida
Oenone fulgida

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