Whorling Wizardry

By The Marine Detective on August 4, 2022

Here’s a big dose of wonder for you.

It’s the time of year when female Oregon Tritons are laying their eggs. These are BIG, predatory marine snails at up to 15 cm long.

Look at how many fertilized eggs are in each “capsule” and marvel at the shape of the egg mass. These capsules are referenced as “sea corn” for this species. It takes each female about 2 weeks to lay her eggs in this wondrously shaped clutch. A friend referenced the shape of the egg mass as being reminiscent of Van Gogh’s “Starry Night”. Agreed!

See the “blank” egg capsules? They have likely been preyed upon e.g. by shrimp, hermit crabs or other snail species. You can even see hermit crabs and snails in these images feeding on the eggs. Some hermit crabs are even sitting on females as they lay eggs. Oh the cheek!

Almost every time I see Oregon Tritons lay eggs, they are doing so as a group. Reportedly, up to 30 individuals have been found laying eggs together.

Why are there so many eggs? Because chances of survival are so low when there is no parental care (other than the architectural marvel of the egg case) and the young hatch into the soup of the Ocean. Planktonic larvae hatch out of the eggs at about 2 weeks of age.

With it taking 2 weeks for the young to hatch, and 2 weeks for Mom to lay the whole mass, the first capsules could be hatching by the time she is finishing her work. I learned from aquarist Casey Cook from her microscopic observations at the Aquarium of the Pacific that, “By hatch time there are significantly less in the egg [capsules] than at the beginning of the lay. We presume the babies eat each other to gain nutrients for creating their first shell layers.”



One study found that, in an aquarium, the larval stage for this species was up to 4.6 years and they only began metamorphosis into their adult form when something was available for them to settle on e.g. rocks (Strathmann and Strathmann, 2007). Further “time from metamorphosis to first reproduction was 3.3 years” (in these conditions in the aquarium).

The scientific name for Oregon Tritons is Fusitriton oregonensis. That’s a whole lot of Oregon in their name and the species is the official seashell of Oregon state (there’s trivia for you). However the range for this species is well beyond Oregon. They are found from northern Alaska to northern Mexico, and Japan. They are common around northeast Vancouver Island. Depth range is reported to be from the intertidal to 180 m. In my experience they are rarely in the intertidal however.

They are also known as the Hairy Triton. “Hairy” for the bristly “periostracum” you see atop the shells which appears to stop attachment of marine organisms. Some loose this bristly covering and, resultantly, can have a lot of settlement and growth on their shells.

The brown structure you see at the opening of the shell is the operculum. This is hard and made of keratin and serves as the door to close the shell. More about that in my “Shut the Door!” blog at this link.

Predatory? Yes! They are among the marine snail species that drill holes into prey, sedate, and slurp. From Invertebrates of the Salish Sea: “Feeds on ascidians, urchins, bivalves, sea stars, brittle stars, chitons, abalones, and polychaetes [worm species] . . . It produces sulfuric acid in its salivary glands, which may help in boring through shells. A gland in the proboscis secretes an anaesthetic used for subduing prey. It feeds with biting jaws as well as a radula . . . Humans should not eat this snail because it carries a pathogen in its salivary glands which can be fatal to humans.”

I have also seen this species scavenge on dead crabs, anemones and fish and eat Lingcod eggs.

All photos: ©Jackie Hildering, northeast Vancouver Island in unceded Kwakwak’wakw Territory.