Oyster Blog — Tideflat Critters

While cleaning the seed racks Nathan stumbled upon a covey of molted (and apparently very sociable) hairy hermit crabs.  Hermit crabs have soft, curled abdomens that have specialized pads on them to keep the crab in place once inside a shell.  They molt and change shells as they grow larger, and they mate during the molting season (which may explain the goings on of this group). We've found them in periwinkle, moon snail, and drill snail shells. (Read our earlier post about hairy hermits here). Parting shot of the molted hermit crab. One of the hermits was happily and safely...

But it sure looks like one! When the tide goes out, juvenile gunnels take shelter from the elements by hiding beneath oyster shells, emerging only to surprise and delight beachcombers. Pictured above is a penpoint gunnel, which can grow up to 18 inches long and live to depths of up to 60 feet. When the tide comes in, the fish swim around and forage for small molluscs and crustaceans. There are 6 species of gunnels found in Puget Sound. Pictured below, the crescent and the saddleback.

The other day the oyster farm was crawling with Monterey dorids. Nudibranchs (pronounced nudi-branks), or sea slugs,  are gastropod molluscs and come in a crazy variety of shapes and colors. (The Monterey dorid is a rather tame looking sea slug, check out this page for photos of other Puget Sound nudibranchs). Monterey dorids resemble another Puget Sound nudibranch, the Peltodoris nobilis, but according to this helpful site, Montereys have yellow gills and the Peltodoris has white gills. We've found both referred to as "sea lemons," which seems like a generic term for a yellow nudibranch. We also found one site...

We don't know where this drill snail is headed, but we wish him happy trails.

This little darling divided the Hama Hama crew into two camps: those who thought it was a squid, and those who thought it was a juvenile octopus. In truth, it's neither. Stubby squid aren't true squid, have a lot in common with octopuses,  and are most closely related to cuttlefish. Like octopodes, they can change color and release ink when threatened. (Go here for photos of stubby squid in various hues). Unlike jet-propelled octopi, stubby squid propel themselves with little wings and normally bury themselves in the sediment instead of swimming around in the water column. Stubby squid eat small...