Tag Archives: palolo

Reproduction is laborious for certain marine worms

Published September 3, 2016 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2016 Susan Scott
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These palolo worm relatives are called green paddle worms, common in eastern and northern Australia. Green paddle worms keep their sex cells to themselves, each segment making and shedding its own gametes. ©2016 Susan Scott

Labor Day marks the unofficial end of summer, the beginning of school, the kickoff of the football season and, where I grew up, the last day of the year that it was acceptable to wear white (go figure).

Those associations with the holiday became secondary to me when I was 11 years old because my mother went into labor on Labor Day, turning our picnic into pandemonium and resulting in a baby brother. Since then Labor Day has symbolized the production of offspring.

In mammals, reproducing is pretty straightforward, but for some marine invertebrates, getting eggs and sperm hooked up is more complicated.

Take a type of bristle worm called palolo worm. (Fijians call them “mbalolo,” hence the common name, palolo.) Palolo worm bodies can have up to 1,000 segments, totaling 16 inches in length. Each segment has two feet, and each foot bears gills, meaning the worms breathe though their feet.

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With toes for scale. ©2016 Susan Scott

Sensory tentacles around the worm’s head help it find tiny living animals to eat. But don’t look for palolo worms hunting during a morning or afternoon snorkel. The creatures hate bright light and come out of their coral rock homes only at night. If you’re in the right place at the right time, though, you might see these worms have sex.

Each year palolo worms grow from their tail ends tubelike sacks filled with eggs in females and sperm in males. In Fiji and Samoa, on the seventh night after the full moon that follows the autumnal equinox (Sept. 22 this year), the worms cast off their packages of precious cells.

The released sex packs have paddle feet on the sides. Light-sensitive eyes running along the midlines guide the paddlers toward the starlit surface. Once there, the gamete tubes twist and twirl until dawn. Sunlight causes the packets to burst open like a milkweed pod, releasing the eggs and sperm to do their job of making more worms.

At least 14 species of palolo worms live throughout the world’s warm oceans, including Hawaii. The sex cell sacks of our worms, however, don’t all rise in one day, but swim up throughout the summer. I’ve seen them under the nighttime dock lights in Kaunakakai Harbor.

Some residents in Fiji and Samoa consider the green gonads a delicacy. People wade out with nets to catch the wigglers near the surface before they explode, and then prepare an annual feast. Some Indonesians also collect and cook palolo worms’ procreative packets.

Because one way or another, moms and dads work their rear ends off for their young, my Labor Day thoughts are with parents. I hope your picnics are peaceful.

Some aquatic worm species pack painful toxins in sting

Published March 25, 2013 in the “Ocean Watch” column, Honolulu Star-Advertiser ©2013 Susan Scott

A bearded fireworm. Used under the Wikimedia Commons liscense. More information: http://en.wikipedia.org/wiki/Bearded_fireworm

“I was badly stung as the worms managed to get into my swimsuit. I ended up with a burning welt across my stomach and fell quite ill,” she wrote. Gerrie still bears the scars, and wonders whether others have had the same experience from what she calls palolo worms.

I don’t think Gerrie was stung by the Pacific island delicacy known as the palolo worm, but instead tangled with a species of fireworm. My reasoning: It’s not the bodies of palolo worms that swarm near the surface.It’s their edible sex organs, and those don’t sting.

Palolo worms and fireworms both belong to a class of marine worms called polychetes which contains 5,300 species.Every segment of every polychete body contains a pair of paddlelike appendages, one on each side.

Sedentary polychetes use their paddle feet to hang on to the insides of their tube homes. Other polychetes, such as palolo worms and fireworms, walk on their flat feet at night in search of crustaceans, snails and other worms to eat. During the day, the roamers rest under rocks and in crevices.

Fireworms get their own family among polychetes, because of the bristly bundles that extend, like tiny whisk brooms, from the end of each foot. Fireworms’ other name is bristleworms.

Some fireworms can extend and retract their bristles. When extended, the worm looks like a cute caterpillar — but don’t be tempted to take it home. Those bristles are barbed and filled with poison.

Bright colors advertise some fireworms’ presence, but the pretty hues are warnings. Fish don’t eat fireworms, nor should people touch them. The sharp bristles easily puncture and break off in skin, introducing the toxin that gives fireworms their name.

Palolo worms are not in the fireworm family, nor are the wiggly parts that swarm (and that people eat). These are the worm’s sex organs, developed once a year as long, narrow appendages full of sperm in males and eggs in females. (I wonder whether they taste different.)

The reproductive organs break off from the body eight or nine days after October’s or November’s full moon.Bearing tiny eye spots, the sex appendages reach the surface in pre-dawn darkness, burst open and do their job of making baby worms. The palolo worm’s body remains on the ocean floor.

Many other polychetes, including fireworms, swim to the ocean’s surface to release their sperm and eggs, each species swarming at a precise time of year.

Although Gerrie’s October timing was right for palolo, it’s likely that, by bad luck, she ran into fireworms going about their annual reproductive frenzy.

No specific antidote or diagnostic test exists for fireworm stings. In most victims, after a few days of a rash or sometimes blisters, the injury heals on its own.

Soon I’ll be sailing to, and swimming in, South Pacific waters. I’m hoping that if I have a close encounter of the wormy kind, I’ll be luckier than Gerrie.

Fireworm Mating from Lutfu Tanrıover on Vimeo.


Marine biologist Susan Scott writes the newspaper column, “Ocean
Watch”, for the Honolulu Star-Advertiser, www.staradvertiser.com

©2013 Susan Scott