How to Catch a Bearded Fireworm (Or a Marine Biologist’s Friday Night)

By Leslie Baehr, November 17, 2014

It is quite difficult to catch a bearded fireworm when it is dark and you are upside-down. But really, it is the only way to catch them.

In order to do so, you will need the following: a black light, yellow lensed glasses, 100 empty film canisters, a bag, a waterproof notebook, a pencil and a spoon. The bearded fireworm is found in the tropical west Atlantic, the Mediterranean, and on some islands in the mid-Atlantic and only underwater, so you will also need a SCUBA tank, a buoyancy compensator device, a regulator, a flashlight, compass, depth gauge, timer, fins, mask and a snorkel. A wet suit, although not necessary, is highly advisable, as hell hath no fury akin to the sting of a bearded fireworm.

Before you put on your equipment, let me tell you what you are looking for. The bearded fireworm, also known as Hermodice carunculata to people of the scientific persuasion, is a long flat worm reddish in color. Bordering its whole body is a beard of white venom filled bristles that “easily penetrate flesh and then break off if this worm is handled. They produce an intense burning irritation in the area of contact, hence the common name of the species. When disturbed, the worm flares out the bristles so they are more exposed,” warns MarineBio.com. Needless to say, it is best not to do anything to piss them off….like, oh say, prying them off their home in the middle of the night and sticking them in a film canister.

At this point you are probably sitting on a dark beach with 100 empty film canisters by your side trying to remember the last time you replaced your flashlight batteries. You are also wondering, “why am I doing this?” and probably “these things better cure cancer or, at least, world hunger.” They don’t.

So what is the grand purpose of all this nonsense? There isn’t one. Not a specific one anyways. In the science world, we call it “baseline data,” which is a brief way of saying that the bearded fireworm is yet another thing we don’t know much about. It is therefore important to learn about it, just in case it’s important. Also, if we know how many of them there are, we can know how many we scared off when we cause their extinction.

Now that you know what you are looking for, corral your supplies and wait until the sky is completely dark. None of this it-is-still-sort-of-light-out,-but-I-can’t-see-the-sun-Can-I-go-now? nonsense. It has to be completely dark, or else your black light and yellow glasses are completely useless and will just look silly.

Next, don your scuba gear and get into the water. Make sure absolutely everything you brought is attached to your person in some form or another or else you will lose it. It may seem like you cannot possibly have enough surface area on your body to attach all your crap.  Figure it out. Remember, this isn’t land people. Gravity doesn’t order things the same way down here, so things can fall-up as well as fall-down. You also probably won’t notice if you are losing something because your peripheral vision sucks with your SCUBA mask on.

Really, all your vision sucks because it’s dark down there and your flashlight only weakly illuminates a small circle. The light from the puny flashlight actually spoils your night vision, but that’s okay because soon you will switch to the black light.

Okay, so you are underwater, you got all your crap attached to you and you just cannot wait to catch some fireworms. Swim out past the sand flat, until you get to the reef. Crap, we didn’t take a compass reading did we? Go back up and do that. That way you know which way is land and which way is the abyss. Got it? Good, now point that sucker toward the abyss and don’t stop until you reach some coral.

You will know you have reached the coral reef because the bottom will no longer be sandy. Instead, the bottom will look like something Dr. Seuss would have built had he been an architect rather than an author. Some corals will look like small trees. Others will mimic giant brains and others will resemble a bush of elk horns. For a long time, people actually had trouble classifying coral. It looks like a plant, feels like a mineral, but acts like an animal. Turns out, coral is not an animal, but animals. A bunch of small living things called polyps (which look like itty-bitty jellyfish or anemones) build themselves a giant apartment out of calcium carbonate (what makes our blackboard chalk). So when you look at a coral, you are actually looking at a bunch of tiny organisms (the polyps) living together in a giant skeleton that they created.

Okay, enough chatter, back to work.

Once you reach the coral, turn off your regular flashlight, turn on your black light and put on your funny yellow glasses. This is why: bearded fireworms, along with corals, anemones and many other coral reef organisms have this crazy ability to exhibit something called phosphorescence. Each phosphorescing animal displays one or more neon colors (which we can see only with our special light and glasses).  The basic result is a killer 80’s rave-like scene or one of those fuzzy posters your parents probably had in the 60’s. Scientists still aren’t sure why many animals do this, but bearded fire worms are known to phosphoresce when they are in the mood to make more bearded fire worms. You could find the worms via a regular flashlight alone, but this black light technique means that they standout like a hooker in church.

This is the part where you get upside-down. The reef will be below you or sometimes at a hill-like angle. You need to get your feet out of the way and your hands toward your work area, which in this case, is the coral reef. If you can think of any way to do this other than upside-down, I am sure there are about fifty Marine Biologists who would like to shake your hand.

For collection purposes, I recommend starting in the deeper water first, say 60 to 100 feet. Since we need samples at all depths, you should come up with a way of collecting the worms at regular intervals until you get to the shallow edge of the reef. Record the depth and size of each worm. The bearded fireworm can grow as long as a small Chihuahua, but most will be no bigger than four inches and will fit nicely into your canisters. The worms will likely be bigger at greater depths. A study on fish in the Mediterranean concluded that bigger fish tend to migrate into deeper waters, possibly to take advantage of the way the cool deep water slows the animals’ metabolism, extending their life. Other scientists say the guy who wrote that study doesn’t know squat.

Now, ladies and gentlemen, the part you have all been waiting for.  Getting the bearded fireworm into a canister is like trying to corral a slippery pig. It is tough due to a terrific rule established by the marine park in which you are worm collecting. The park does not allow people to wear gloves. Gloves give divers the burning desire to touch things, and touching things in a fragile coral reef leaves most of them dead. Instead, you will need your spoon. Pry the little sucker off whatever coral he is munching. The fire worm will flick upwards, most likely directly at you because you are upside down (See, I told you to wear that wetsuit).

All at once you must now move away, ditch your spoon, open your canister and keep your flashlight on him so you don’t lose him in the dark. Three things, two hands. Do the math. It’s freakin’ tricky. Don’t bring the canister up toward the slowly falling worm too quickly or you will generate a current sending him further upwards.

Got him? Good. Now go find 99 more.

LESLIE BAEHR is a science writer and water junkie currently based out of New York and Los Angeles.  For more blog posts see here.