The Top Thirteen PolyChaetes

Written by Jonathan Wojcik

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   The Annelids are a group of animals most of you know best for the earthworms and leeches, both belonging to the class Clitellata, but it is their sister class the Polychaeta which displays the most extreme diversity, with over 10,000 known species found in brackish or salt-water environments around the globe. Unlike the earthworms, Polychaetes can possess dozens of legs, claws, tentacles, antennae and complex mouthparts, an anatomy that has adapted to an insanely broad variety of lifestyles. Some are beautiful, some are disturbing, many are both. We're going to count down my picks for the top thirteen weirdest and wormiest, because on Bogleech, we appreciate too many worms for a top ten.


#13: Tomopteris


   An inhabitant of the deep sea abyss, Tomopteris may be one of the most beautiful of all aquatic worms, its rippling transparent body as flat as a piece of paper, gliding through the water like a Chinese dragon kite. When attacked, it scatters thousands of luminous particles from its legs in an attempt to confuse predators and cloak its escape. Its leg-like extensions or "parapodia" are also where its eggs develop, until they're shaken out into the water.


#12: The Sea Mouse


   Common in shallow, sandy waters, these cute little critters were given the family name Aphroditidae after the Greek goddess of love, allegedly because they resemble a woman's pubic region. This is science, don't be a baby. Predators of other soft-bodied invertebrates, they creep about with their head plowing the sand, sniffing out their next meal.

Peter Edin

   To protect the rest of their bodies while they hunt, sea mice are densely lined with sharp, crystalline bristles that filter sunlight into intense color patterns, believed to function as a false toxicity warning. It's quite an elaborate bluff on the worm's part; so elaborate, it could serve as a revolutionary model for fiber optic technology. Each bristle is comprised of several million hexagonal cells or "photonic crystals," the first such structures ever documented in the nature world and more effective at manipulating light than any previous invention of man.


#11: Pig Butts & Parchment Worms

MBARI


   Just a little less elegant than our previous worms, Chaetopterus pugaporcinus literally translates to "worm like a pig's rear," with segments so flattened and inflated that it loses any semblance to a worm-like shape. About the size of a grape, it drifts in the deep sea abyss and dangles a net of sticky mucus believed trap planktonic food. Lacking reproductive organs, the pig butts are believed to be larval, but their adult form has yet to be determined.


Fredrik Pleijel

   Other members of the order Chaetopterus mature into what are known as parchment worms, who hide their beautiful, delicate bodies in horseshoe-shaped burrows. The rippling of their many fins and paddles keeps water flowing through their tunnels, trapping bits of food in specialized filtration organs.


#10: Syllid Sex-bombers


   Several worms of the order Syllidae spend their entire adult life buried deep in the sand and mud of shallow seawater, feeding on tiny organisms well away from the prying eyes of predators. Unfortunately, they can't very easily propagate the species without leaving the safety of their burrow...or can they?

   Though the mature worm is asexual, the posterior end of its body will divide into male or female sections with their own heads, eyes and swimming paddles. During the high tide, these portions break off, mingle with others of their own kind and explode in the water, releasing fertilized eggs. If they get eaten by a predator, the original worm can always just make more, mating remotely through its suicidal, cloned offspring.


#9: Histriobdellidae


   Among the tiniest of all Polychaeta, this peculiar group is so simplistic in form that it was once considered its own separate phylum. Smaller than a pinhead, these worms both look and act remarkably like lice on the bodies of lobsters, crabs, isopods and other crustaceans. Sucker-tipped feet cling firmly to the surface of a host's smooth exoskeleton, and powerful drilling jaws penetrate the thick armor to feed on host fluids.


#8: Symbiotic Scale Worm



   Lacking a mouth or digestive system, these worms are sustained entirely by the organic waste of symbiotic bacteria, in turn thriving upon such raw materials as carbon monoxide, hydrogen sulfide, oxygen and methane.


#1: The Bone-Eating Snot Flower


   As the largest single concentration of meat in the animal kingdom, the death of a whale is one of the deep sea's most celebrated events. The titanic carcass can take months or even years to completely decompose, and becomes a veritable cornucopia of new life as thousands of animals flock to the free buffet - some of which have evolved to feed on absolutely nothing else.



   Stripped of most flesh by squirming hordes of hagfish and ghostly white crustacea, a fallen leviathan's monolithic skeleton quickly comes alive with a tentacled bouqet of bizarre organisms known to some researchers as "zombie bone worms." Structured more like a plant than an animal, the female Osedax mucofloris - literally "bone-eating snot-flower" - lacks a mouth or stomach, relying on a network of "roots" to tap into its only food source; the fatty oils contained within whale bone. Like the thermal tube worms, it relies on unique symbiotic bacteria to process this nourishment.

   When Osedax were first discovered as recently as 2002, biologists were perplexed by the appearance of only female reproductive organs in every mature specimen, despite the presence of male sperm and millions of fertile eggs. As it turned out, the "missing" male worms were there all along, plentiful but microscopic, living inside the bodies of the females. Continuously fertilized by her tiny inner harem, the lady snot-flower pumps thousands of eggs into the surrounding water, to drift like dandelion seeds until another colossal corpse appears on the sea floor.