Herman's Mini Adventure
by Michelle Hollander
It was as if we had stepped into a storybook. One of our hermit crabs decided that his whelk shell just wasn't big enough anymore. He left it in search for another home but didn't find one that was suitable. Herman, as we will call him, seemed a little confused. Rather than protecting his soft body, he climbed on top of a moon snail shell and just sat there. We watched the scene unfold in our weekend touch tank, as mud snails attempted to escape, the green crab and Asian shore crab scuttled past, and our horseshoe crab meandered along. The clam and oyster just sat around, while the sea cucumber squished itself into an old mussel shell. Still, Herman just sat there.
Scientific studies have shown that Herman's species, Pagurus pollicaris, "vary their preference for shells of a certain weight and volume, depending upon the species of shell". Additionally, when choosing shells, alterations to a shell's center of gravity and axis could factor in the crab's dismissal of a shell (Conover 1978). It turns out many factors are at play.
We decided to intervene after several customers got a chance to see what a hermit crab looks like without its shelf. Naturalist, Molly, found more shells, and picked a whelk shell we thought might be the right size. We gently placed Herman on the opening. He scooted inside and didn't discard the shell – and that was the end of that.
Touch tanks are a common feature of our weekend scheduling and showcase the myriad of invertebrate species that live here in West Harbor. We cannot promise a shell-less hermit crab, but there is always something new to observe.
In addition to our touch tanks, we constantly try to find new ways to make the WaterFront Center experience special. Each day, we put out a chalk-board A-frame with information for the day, including sunrise and sunset, tides, and weather information. However, we also include that day's wacky/ bizarre holidays. Did you know that July 10th is "Teddy Bear Picnic Day" or that August 7th is "Raspberries and Cream Day"? Plus, we have some hidden artists that make our boards look extra special.
We hope you will stop by to experience all that the WaterFront Center has to offer!
Conover, M.R. 1978. The importance of various shell characteristics to the shell-selection behavior of hermit crabs. J. exp. Mar. Biol. Ecol. 32, 131-42.