Ever been tidepooling and poked your finger in a squishy sea anemone just to see its petal-like arms grasp your finger? You may have noticed a somewhat sticky feeling as you shake those arms free, but how can something be sticky underwater? That sticky sensation you feel are actually nematocysts, which are microscopic stinging cells that sea anemones use as tiny harpoons to paralyze and capture prey. Even the biggest of sunburst anemones (Anthopleura sola), do not have nematocysts strong enough to have an effect on our human thick-skinned digits. However because nematocysts can only be used once and new ones must be re-grown, refrain from poking too much so that anemones don’t go hungry.

[Photo and caption by Karli Chudeau]

Fylling, M. (2015). Fylling’s Illustrated Guide to Pacific Coast Tidepools. Heyday, Berkeley, California.

[Edited by Maggie Creamer]