TYBEE BEACHCOMBER | MAY 2019 23
SODA STRAW WORMS
Some of the small holes that you see in the sand throughout the lower intertidal zone of Tybee’s
beach are made by thin worms. Although they are thin and look more like red threads, some of
them can be fairly long and up to two feet in length. So their holes might extend down 2 to 3
feet into the sand. These worms are classified as Polychaete Worms. They are segmented like
earthworms, but each segment has a pair of small bristles or paddle-like extensions sticking out
of both sides. The name Polychaete means “many bristles,” so the long thin body looks slightly
fuzzy. Polychaetes have hemoglobin in their blood, and since they have thin, soft skin, the red
color usually shows through.
Some Polychaetes are active and are constantly burrowing through the sand hunting for food.
They use their bristles/paddles for crawling and their muscles for burrowing. Other Polychaetes
are sedentary and produce tubes to live inside. Depending on the species, they make their tubes
from a variety of substances, including paper-like parchment, sand grains glued together, and
hard limestone produced from calcium that they extract from seawater. Sedentary Polychaetes
mostly stay within their tubes and use highly modified head appendages that stick out and
gather food from the water.
A good example of a Polychaete that makes a parchment tube is the Soda Straw Worm. We
don’t usually see the worm, but I’m pretty sure you have seen their tubes on Tybee’s beach.
A Soda Straw Worm makes a cylindrical paper-like tube that is about a quarter of an inch in
diameter. To help stiffen the tube a bit, it adds a few small sand grains, so its tube is like a paper
drinking straw. Usually its tube sticks up above the sand a fraction of an inch, and this helps
to prevent sand from entering and falling down into the tube. Deeper down, the tube is more
parchment and less sand, so it is more like a soft, white cylinder of paper. The Soda Straw Worm
itself is thin and round, but can be up to 2 feet long! So its tube can be pretty long also.
When old tubes wash out of the sand and eventually drift up on the beach, they look like strips
of paper (rather than cylinders), as if someone has dumped their paper shredder on the beach.
Sometimes, as old tubes drift in the shallow water, they tangle together and accumulate in large
masses, and then get washed up as a pile.
On Tybee, Soda Straw Worms live mostly just offshore of the low tide line. But on days when
the tide is extra low around the new and full moon, the water sometimes goes out far enough
that a few of the Soda Straw Worm tubes can be seen sticking up slightly above the sand bottom.
The better locations for seeing them are just inside the inlets at the south and north ends where
the surf energy is less than on the main beach front.
Dr. Joe Richardson (Ph.D. Marine Sciences) is a retired marine science professor with 40 years
of research and teaching experience along GA, the southeastern coast and Bahamas. Besides
research, he conducts Tybee Beach Ecology Trips (www.TybeeBeachEcology.com) and frequently
posts pictures of their findings on his Tybee Beach Ecology Trips Facebook page.
Beach Walks
with Dr. Joe
By Dr. Joe Richardson
/(www.TybeeBeachEcology.com)