Bristleworms Spawning in an Aquarium Sends Shivers Up Our Spines

Bristleworms, for some, are seen as a welcome member of a diverse clean up crew for marine and reef aquariums. For most others, however, the mere sight of a bristleworm is enough to cause a panic, as stories persist throughout the hobby of these worms causing untold problems. If you fit in the latter group, then you might want to turn away now. In the video above, captured by Marvin’s Reef, a plethora of sand-dwelling bristleworms are seen spawning in a marine aquarium. In a tightly synchronized event, the worms emerge from the sand and quickly spew forth clouds of reproductive materials. The spawning goes on for a few minutes, and toward the end the action really starts to heat up as more worms participate quite vigorously.

Bristleworm breeding activities aren’t unusual in a marine tank. In fact, these worms reproduce all the time. What’s unusual about this behavior, besides the fact that it was all caught on tape, is that it’s occurring during the day. These worms normally only venture out at night and usually retreat rapidly when any light shines on them.

If you have a bristleworm infestation, like Marvin’s Reef is sure to get after this event, there are a few steps you can take to thin down the herd. For one, ease up on the fish food. Because the worms are detritivorous, they eat all of the leftovers and even the stuff that’s rotting away in the nooks and crevices of the rocks. After a bit of nutrient reduction, you could always manually remove the worms. This can be accomplished with baited traps, countless hours of doing it by hand, or with the help of a predator. Most fish won’t touch bristlworms, but some gobies and wrasses have been known to partake of the bristly treat. If you do go the manual route and do it yourself, be very careful as the worms do have natural defenses. Their bristles can embed into your skin and cause slight irritation and even pain.

  • Lee

    Feel bad for those fish stuck in the crossfire…

  • clippo

    quite a few dottyback species will predate small bristelworms also.

  • Henryw25

    That’s pretty scary. It seems like an apocalypse! I fortunately own most of their natural predators.

  • clownfish1976

    I can see the larger bristle worms spawning, but can someone tell me what all the much thinner clear looking worms are that are sticking out of the sand in the video? you may have to expand to fullscreen and use Hi Def to see them…. are they spaghetti worms? or something else?

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