Ocean Watch

"Strange Invasion," read the Aug. 7 Star-Bulletin headline. "Sea worms wash ashore at Ala Moana Beach Park."

Seeing several hundred writhing worms with centipede-like legs is an experience most people could live without. But when these "strange sea creatures" appeared on a popular beach, I was off island and disappointed to have missed the event.

Had I been here, I would have rushed to the site. Bristle worms just don't visit that often.

Bristle worms' formal name is polychete worms, poly meaning many, chete (pronounced keet) meaning hair.

This hairy name refers to the bristles that protrude in bundles down each of the creatures' two sides.

These bristles are obvious in some species, like the ones that washed up at Ala Moana.

The newspaper pictures of those worms look like fire worms, carnivorous creatures that live beneath rocks and in reefs from shallow water to 600 feet deep. Why they washed up on the beach that day, I don't know. A Health Department spokeswoman said the worms got in trouble because a rainstorm diluted the ocean.

That explanation alone seems weak, given all the rain that falls here in Hawaii. My guess is that the worms were spawning in the wrong place at the wrong time.

Spawning among some kinds of bristle worms is a notable event. One of these species is the palolo worm, found in Hawaii but better known in Samoa.

When it's time to reproduce, palolo worms cast off their sex cells, at night, inside wiggly cylinders called epitokes. Running from end to end on each epitoke is a row of simple eyes.

At dawn the light triggers a synchronous bursting of these cases, creating a new generation of palolo worms.

That is, if hungry humans don't get them first. These worm ends are popular food treats in Samoa. A moonlit night of palolo spawning there is cause for a communal netting ending with an epitoke fry.

Fire worms are another story. Not only does no one want to eat them; no one wants to touch them. To touch a fire worm is to get burned.

Fire worm bristles are hollow, minute spikes that penetrate human skin easily. When the spike breaks off, it releases a toxin inside, causing burning, itching, numbness or rash.

You might be able to lift some fire worm spines out with sticky tape, but mostly, if you're stung, you're stung. The best way to deal with fire worms is to follow the fishes' example: avoid them.

Other polychetes use their bristles only as harmless feet. Some are designed for digging; others resemble Velcro hooks that hang onto the inner walls of self-made tubes.

A few species carry their tubes around with them, but most are anchored in rock or reef, such as spaghetti worms and feather dusters, both common in Hawaii's waters.

Tube dwellers deal with their waste products in unique ways. Some use their bristles to beat water up and down their tubes, thus gaining oxygen and losing wastes. Others transport their fecal pellets to the outside in moving tracts along their bodies, like tiny conveyer belts.

A few have a less elegant fix: When the time is right, they turn upside down in their tubes, poke out their rear ends and defecate.

Of the Ala Moana Beach worms, a lifeguard said "they're a nightmarish cross between a centipede and a sea urchin." I'm sorry I missed them.