Natural History
Totally Tubular
Some marine worms live their entire lives inside a cylinder of their own making.
Story by Suzanne Gerber ~ Photos and Captions by Barbara Shively
Even if the word “worm” gives you the heebie jeebies as you conjure grade-school boys dangling them in front of your face on the playground, you’re going to love the elegant underwater creature known as the feather duster. Marine worms (or polychaete for Graecophiles) are technically members of the same family as their bait-worthy cousins. But for all practical purposes, they have nothing in common—starting with the fact that they are beautiful, decorative, and, to Barbara’s photographic eye, the equivalent of flowers in an underwater garden.
Barbara and I, who don’t dive together nearly enough, share an appreciation for delicate marine tube worms, which come in more shapes and sizes than fleeces in an Eddie Bauer catalog. These tiny treasures create tubes from sand and mucus, then burrow their bodies inside the tubes, which they anchor to the reef. This is why they resemble flowers or feathers more than worms.
In the last issue, at the opening bell of the holiday season, we took a close look at Christmas tree worms. This time we turn our focus to relations of theirs called feather duster worms. Like their festive cousins, they conceal their vital bits inside their tubes. But where Christmas tree worms have two sets of radioles (the feather-like antennae that protrude from the coral), feather dusters sport a single flowery crown. On top of that, their distinctive tubes can often be seen, the underwater version of “visible panty line.”
Perhaps this is the key to their vulnerability. The merest disturbance of molecules within their space is all it takes to get them to shrink deep inside their protective tubes. As Barbara puts it, “Calling them camera-shy is an understatement! And yet it’s fascinating to attempt to photograph them. The name of the game is to approach very slowly and gently. You may only get one chance because the flash can also make them retract.”
Once a worm insinuates itself into a tube, it is wont to leave, and many never vacate the premises for the duration of their life. While they can shimmy up and down in their tube effectively—and sometimes quickly—that’s pretty much as far as they’ll get. Should conditions hit a code red, however, some worms have been known to abandon ship. But since they’re lacking in locomotion skills, and with tubes only open at one end, this truly is the last resort.
What’s for supper?
Because foraging is out of the question, these worms have evolved into excellent passive hunters. It’s not for nothing that they tend to take up residence in shallow marine environments, which are packed with vast resources of the small, particulate, edible organic material that worms thrive on. And with tentacles on their heads that extend into the water column, capturing food is not a problem. (What is a problem is when a passing butterflyfish nips the worm’s tentacles off. Ouch!) It’s the arrangement of these branching tentacles, which resemble a bird’s feathers or that low-tech domestic cleaning apparatus, that gives this fellow his colorful name.
Since she’s been diving and snapping—for the past decade or so—Barbara has captured many images of these lovely, lilting creatures. While there is much overlap in their appearance and biology, it’s the differences that keep us on the lookout for them.
One of the most impressive of the species is the Giant Feather Duster Worm, whose appetite is so voracious (relatively speaking) that it must exist in areas with moving currents that bring in new plankton. In fact, when the water motion slows down too much for its liking, it creates its own water current by waving its “feathers” in an activity called active suspension feeding. For the record, the Giant Feather Duster isn’t really a giant at all, typically measuring just 10 inches long by half an inch wide.
Can you guess how the Magnificent Feather Duster Worm got its name? Its three- to six-inch crown earns it the distinction of being largest of all Caribbean feather dusters. Brandishing a double circle of radioles in a wide range of colors and patterns, it very closely resembles bird feathers.
The Magnificent Feather Duster may be the biggest tube worm in town, but he’s not the most popular. The poetically named Social Feather Dusters cluster in large groups. Here in Turks & Caicos, Social Feather Dusters, whose tubes measure a mere quarter-inch in diameter, are usually found in shades of white and violet, but if you venture further afield in the Caribbean, you’re more likely to spot them in shades of brown.
Another variety, the Split-Crown Feather Duster Worm, takes its name from that fact that the circle of radioles on the top of its head appears to be split into two halves. The long, graceful radioles can stretch two inches beyond its tube.
One of the few examples of marine worms that does resemble its earth-crawling cousin is the Bearded Fireworm. The repetitive segments that divide its body are plain to see, and it’s easy to envision it creeping over the reef. But don’t accidentally try to bait your fish hook with one of these babies: they’re covered with stinging white bristles!
Beautiful, delicate, and a vital part of the underwater ecosystem, feather duster worms are another poignant example of why we must be careful when we swim, snorkel, dive or boat around coral reefs. The worms in their tubes and their radioles are very fragile and will likely be damaged or destroyed if we so much as bump into them with our bodies, fins or anchors. Feather duster worms may be easy to take for granted, but it would be nothing short of a tragedy if they were to disappear from the planet.
New York-based Suzanne Gerber writes about scuba, travel and health for a variety of publications. Book your next dive trip by contacting Suzanne at suzanne@worldofdiving.com.
Avid underwater photographer Barbara Shively discovered Grand Turk diving in 1997 and has returned every year. It is her passion to share the coral reefs’ beauty through her photographs, many of which can be viewed and purchased at http://shivelygallery.com/. A variety of her prints are on sale at Art Provo, located in The Regent Village, Providenciales.
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Tucked at the northeast corner of North Caicos is Greenwich Channel, formed at the northern tip of Bottle Creek by the convergence of Horsestable Beach and Bay Cay. By using a drone Master/Craftsman Photographer James Roy of Paradise Photography (www.myparadisephoto.com) was able to capture this dramatic abstract image. The shallow water and shifting sandbars and channels create surreal natural art in many hues of turquoise and green.
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