Red Worms in the Sand of My Saltwater Aquarium

Many saltwater aquarium owners find themselves troubled when they lift up a rock and see red worms scurrying through the sand. These creatures, known as bristle worms, are a common sight in saltwater tanks. The worms typically resemble centipedes and can be almost any shade of red. Though the worms are typically smaller than the tip of a finger, they can grow to several inches.

  1. About Bristle Worms

    • Bristle worms are detritus feeders, which means that they eat dead and decaying material. They are frequently attracted to leftover fish food, decaying rocks and even dead fish. Though they can grow up to 20 inches long, most aquarium bristle worms are very small. They are typically found living under living rocks and coral, where they eat dead portions of the rock.

    Bristle Worm Causes

    • Most saltwater aquariums have at least a few bristle worms. These worms tend to grow naturally in a well-established tank. Aquarium hobbyists who have coral and living rock are more likely to see them because these items provide a good hiding place as well as nutrition. Sand in an aquarium can also contribute to bristle worm growth. The worms may burrow in the sand, and the sand helps to capture dead and decaying material for them to eat.

    Bristle Worm Benefits

    • Bristle worms can be a beneficial part of an aquarium ecosystem. These animals help to keep the tank clean and may prevent the growth of infections and disease that are frequently caused by poor tank hygiene and decaying matter. These worms are also fascinating members of a tank community and contribute to biodiversity. They can be beautifully colored and their unique, detritus-eating behavior is fascinating to some aquarium owners.

    Bristle Worm Risks

    • Very large bristle worms can pose a risk to some fish in your aquarium. Some larger worms are capable of stinging and may exhibit predatory behavior, chasing and eating other fish in the tank. If bristle worms have grown out of control in your aquarium, simply fish them out of the tank. Many pet stores sell inexpensive bristle worm traps for this purpose. Put them in a separate tank if you're interested in watching them or donate them to a zoo or pet store if you simply want to get rid of them.