Ocean Watch

Monday, February 8, 1999

Ubiquitous sea spiders
surprisingly hard to find

Last week, while researching my column about land spiders at the beach, I was reminded of several wonderful moments in my life regarding sea spiders.

Sea spiders are true marine creatures that live on ocean floors all over the world, from pole to pole, in shallow waters and deep. The scientific name of all sea spiders is Pycnogonida (pick-no-go-nid-a). These creatures may or may not be related to true spiders, but they look like them and have some marvelous characteristics all their own.

Anyway, when I first learned about these animals, I was a new student at the University of Hawaii, fulfilling a lifelong goal of studying marine biology. It was an exciting time for me.

"I learned about pycnogonids at school today," I told my husband after class one day. He was interested in marine biology but at that moment was only half listening.

His head shot up. "What?"

"Sea spiders. They're everywhere in the ocean."

"What did you call them?"

"Pycnogonids."

He burst our laughing.

"What's so funny?"

By then he was laughing so hard tears filled his eyes. Finally, he choked out, "I thought you said you learned how to pick your gonads at school today."

To this day, neither of us can say the scientific name of sea spiders without cracking up.

For years after that, I kept an eye out for these fascinating invertebrates. My textbooks say sea spiders are fairly common, either clinging to their soft-bodied prey (anemones, sponges, worms), walking slowing along the ocean floor or swimming by beating their legs up and down. Since they look like spiders, having tiny bodies with long, gangly legs, you wouldn't think they would be hard to spot.

Still, I had no luck.

Then, a few years ago, a couple of grand sea spider moments came my way.

The first occurred at Palmer Station, a U.S. research facility on the Antarctic Peninsula. A worker was giving a tour of the station. "This is our aquarium where we keep interesting local specimens," she said with a wave of the hand. And there they were: two enormous, beautiful sea spiders.

"You finally found some you-know-whats," my husband whispered, smiling.

The creatures were as big around as large grapefruits and pumpkin-orange. I watched them stride around the tank, then entwine in some kind of mating ritual. It was a fine moment.

Later that week, I visited an Antarctic beach bathed in hot water from underground volcanic activity. And there on the lava-black sand lay several of the giant orange sea spiders, dead from the boiling water. That time, I even got to touch the spiders.

Sea spiders have no stomach and no respiratory or excretory organs. Digestive branches run down the legs, which permit gas exchange and pass wastes. The reproductive systems of sea spiders are also in the all-important legs.

Cold waters have the largest sea spiders. The biggest of these has a body 2.5 inches long with legs spanning 1.5 feet. Sea spiders living in warm waters such as Hawaii are small and inconspicuous.

After all these years, I still haven't seen one here -- and I still can't say the word pycnogonid without smiling.