The Science of the Clams

The intruder made a beeline for the shore, slowed and placed her hands in the frigid water. I watched, hoping she wouldn’t notice something I coveted and wanted to keep quiet: an unusual sea squirt species. She rinsed her hands, shook them off, turned and walked away. My secret was safe.


October of 2014, while beach combing at Cornet Bay during a particularly low tide, I snapped a photo of a something I’d never before noticed.


I didn’t think much of it at the time because there were too many creatures new-to-me to become obsessed with just one. At home, I Googled “brown” “squirt” “sea creature.” The search turned up “tunicate.” Kozloff‘s (p 31) description seems to fit what I found, “more or less cylindrical and abruptly cut off,” “rather solid and firm,” “the size and shape of the openings and the siphons subject to muscular control.” During a -2.0 foot tide this spring, I returned to Cornet Bay to track down the tunicate, which was like trying to finding a needle in a haystack. Each set of siphons is small, no more than an inch wide by two inches long, and the beach is 30 feet wide and a mile long. After wandering around for awhile, success!


Unable to determine the sea squirt species by viewing images on-line, I checked in with two scientists, hoping they could identify the creatures outright, or at least lead me in the right direction: Dr. David Cowles, Professor of Biology at Walla Walla University, Invertebrates of the Salish Sea website manager and researcher, has answered my marine life questions in the past; Dr. Gretchen Lambert, a marine biological consultant, ascidian taxonomist and sea squirt sleuth, Ascidian Home Page for the United States website manager and researcher, was new to me. I emailed both a few photos from my first trip out this year with the subject line “a little help (please) with identification of a sea squirt.” Dr. Cowles offered to collect and dissect one and Dr. Lambert gave me her best genus guess (Pyura), a link to a sea squirt dissection video and offered to dissect a specimen if I mailed it to her.

Tunicate top Piddock clam bottom 6-1-2017 10-12-57 AM

I found a photo of a sea squirt species that looked almost identical to the creature I’d photographed on that first trip. Species: pyura vittata. A few trips later, I sent the scientists more photos. And that is when Dr. Lambert burst my rare sea squirt finder bubble. With the additional information, she suspected that the siphons were likely that of a clam, probably a geoduck, “You will have to get a shovel and dig down and see what you come up with.” Dr. Cowles agree. Dr. Lambert tried to be gentle by sharing the story of a colleague who’d made a similar, but more embarrassing mistake, but I still felt bad. Viewing images and the video Compare Three different Clam Siphons– Kitsap County, WA, I suspected the siphons were that of the Rough piddock clam. I awaited the next series of super low tides with a mixture of impatience and excitement.


On Monday, June 25, I set out for the site. I brought: a clamming license, two plastic bags, two shovels, a backpack, a camera and pair of gloves. I arrived forty-five minutes before a predicted -2.9′ tide to an empty beach, chose a siphon as far from the tide line as I could find, placed the shovel blade about six inches to the side of it, and dug up a big scoop of muddy, clayey sand. The siphon disappeared, but I knew that the shell could not move. A scary surprise arrived in one of the first few shovelfuls: the shell-less neck of my mollusk. I did exactly what any self-respecting prospective criminal would do: threw it in the water before anyone noticed. If it turned out to be a geoduck, I’d be breaking the law by not digging up the shell. I felt the pressure of time, that of the soon-to-be turning tide, and the knowledge that if I weren’t successful, it would be a month before another adequately low tide arrived. Messy layers of gunmetal gray, quarter-inch thick clay sheets mixed with sand piled up beside the hole as I dug with the shovel and my hands.


 Half an hour later, the tide turned. I regretted my decision to leave the bucket at home as I bailed the clayey water with a Macy’s bag. Tired, frustrated and covered with mud, I knew that if I didn’t find the shell soon, the rising tide water would overwhelm my bailing efforts. And then I saw it–the neck of a clam! I bailed like crazy to get a few good photos of the siphon plus neck plus clam shell. By then, the jaggedy hole was about two feet in diameter and 18″ deep. I carefully extracted the shell and placed it on the sand, the way a doctor places a baby on its mother’s stomach after childbirth, except without all the pain and blood and slime and stuff. I couldn’t believe my last-minute luck. After taking a few more photos, I returned the muck I’d dug into the hole, packed up and left. No one saw me, except two guys gill-netting for salmon.


Once home, I cleaned, photographed and sliced open the Rough piddock clam, then sent off photos to Dr. Cowles, who offered to show me sea squirts in his lab later this summer, and Dr. Lambert, who said that she planned to use a few of the photos to show her Ascidian Taxonomy students another reason to be cautious about sea squirt siphon identification. The Rough piddock clam meat, sauteed with oil and garlic, tasted no different than your average clam. Fun facts from the Invertebrates of the Salish Sea site, “It can extend its siphons up through as much as 48 cm of clay plus 30 cm of sand. When boring, it holds onto the substrate with its foot and rocks its shell up and down against the burrow walls by alternately contracting its anterior and posterior adductor muscles. After each stroke, the animal rotates about 12 degrees. It takes about 30 rocking motions to turn in a complete circle, which takes about 70 minutes. After about one complete turn, the direction of rotation is reversed. Periodic body contractions create a current which shoots debris up and out the incurrent siphon. Lives about 8 years, and never completely ceases digging its burrow.”


In the end, I’m okay with the fact that I didn’t discover a rare sea squirt species, because if I had, everyone would be out there tramping all over the siphons while trying not to do so. Nobody much cares about Rough piddock clams. And now I can admire them at my leisure during the dozen extreme low tides they are visible without having to worry that someone might want to dig them up. I revel in the fact that I found a beautiful, uncommon sea creature at one of my favorite places, Deception Pass State Park, and the serendipity of finding scientists willing to share what they know with a complete stranger and being as excited as me to solve the mystery.

Piddock 6-26-2017 6-04-56 PM

On July 25, I took Dr. Cowles up on his invite to visit Rosario lab. He showed me some sea creatures in an open-topped tank including a swimming sea scallop, delicate crab, lemon drop, sponge, chiton and, of course, a sea squirt! Then one of his students, a diver named Monica (many of the students dive!) showed me the things in her tank, which included several different species of sea squirts.

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