Mar 13, 2008: Sea Cucumbers. Even wierder than moon snails.

Here are some facts you probably didn't know about sea cucumbers:

1. They breathe through their anus.
2. They have a compound in their skin called catch collagen that allows them to liquefy or melt on command. They use this skill to escape into small, safe crevices to evade predators.
3. They have an escalating response to stress. If you poke them with a stick, or hold them in your hand, they'll probably goopify. If you continue to mess with them they may puke their guts out, or eviscerate themselves. If you really, really bother a sea cucumber, it will inhale a bunch of water through its anus and then rupture its hind end to expel a bunch of noxious chemicals. When this happens in an aquarium it can kill all the tank mates-- something aquarium keepers call a "cuke nuke."

Step 1: Goopification

Sea cucumbers, together with sea stars and sea urchins, are echinoderms. There are 900 known species of cucumber; the one pictured here is Parastichopus californicus, or the California Sea Cucumber. It's supposed to be nocturnal, but we found two cucumbers passing a nuit blanche on a low tide in February. When we found the first one, Dave, an oyster picker who's worked on the Hama Hama tideflats for over a decade, said it was the first cucumber he'd ever seen on the beach. So we felt really good about finding another one a couple hundred yards away from the first.

Sea cucumbers are very edible. The 5 longitudinal muscles in the cucumber are considered a delicacy. But they were over harvested a couple of decades ago in the Canal, and are only now making a comeback. So I'm not going to post any sea cucumber recipes. They eat passing plankton and plant and animal detritus off the sea floor, and are important ecologically.

Don't mess with the cucumber.