Tresus nuttallii (gaper)

Found in area 5.

You can find gapers at the Cove at the mid tide level. If you get squirted it’s probably from a gaper. The gaper’s body, like the geoduck’s is too large for its body but not quite to that proportion. The geoduck really hangs out of the shell all over so that its shell looks like a saddle on a horse. The Tresus nuttallii shells do not close all the way. They leave room for the animal body to hang out somewhat at the neck. To distinguish between the two, look inside at the hinge. The gaper has a hinge with a little teardrop indentation shaped in it. The geoduck has a hinge that looks like a strip of leather binding the two shells together. The only other shells that could be mistaken for one of these species is (1) Saxidomus nuttallii which frequently is stained black on the outside with a shell that is heavy and thick and is stained purple on the inside. The other clam it could be mistaken for is (2) Saxidomus gigantea which has a hinge like a geoduck and three teeth at the hinge. It has a shell that is not as heavy and thick as Saxidomus nuttallii. When closed there is virtually no gap at the siphon end.

Seagulls like to fly these clams up 15 to 20 feet high and drop them so they break open and they can feast on the animal inside. This leaves the beach littered with broken shells. Often when looking at broken shells you’ll find ones that look like birds in flight. That’s from the Tresus nuttallii. At the hinge the teardrop shape looks like a bird body and the wings are the remains of the hinge.