Are Bristleworm Stings Dangerous?

There are over 8,000 species of Polychaeta (bristleworrm) in at least 80 families. While most live in the sea, they can also be found in moist soil. They can range in size from 1mm up to two meters or more. There are two types of bristleworm including: Errant Polychaetes and Sedentary Polychaetes. Errant Polychaetes are free moving and Sedentary Polychaetes live in tubes or burrows. Errant Polychaetes are often used as fishing bait.

These elongated segmented worms can also be found under rocks and coral and the marine varieties can often be found on the surface during reproduction. The bristleworm is considered one of the most beautiful types of worms due to its wide variety of iridescent colors ranging from read and pink to green. The fanworm is considered the most beautiful of all bristleworms thanks to its colorful and patterned fan feeding tentacles.

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The bristleworm has numerous segments and “bristles” on each side of its body. They have two to four pairs of eyes, sensory organs, a mouth, and a brain. Most have feeding structures on their heads and a well-developed circulatory system. While a bristleworm may look and sound quite scary, it is not an aggressive animal – at least not towards humans. A bristleworm will only bite a human if it feels threatened or if you are handling it. And yes, accidentally brushing up against one is considered a threat.

The bristles or “setae” of the bristleworm are so tough, that they can penetrate skin, causing a painful “sting.” Depending on the type of bristleworm, the sting can cause burning, inflammation, numbness, pain, redness, and swelling at the bite or sting site. The burning sensation may be caused by calcium carbonate or silica that may be found in some bristleworms’ hairs/setae. If the symptoms listed above are minor, there are several was to relieve these symptoms at home. First you should remove any bristles with tweezers or tape. Next, apply alcohol or topical acetic vinegar. If you are experiencing pain, this can be relieved with one to two Tylenol every four hours or one to two Advil every six to eight hours.

If you notice signs of infection such as heat, redness or pus, apply a topical antibiotic ointment such as Neosporin. If a burning sensation is present or you notice inflammation, apply hydrocortisone cream two to three times per day.

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If any of the symptoms listed above are severe or they do not subside within a few days, contact your physician. Oral antibiotics may be necessary if an infection has developed. Antibiotics are usually taken for up to five days.

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