Thursday, June 17, 2010

Almost a one-armed starfish

It's been a critter-full vacation. We're packing today, heading home tomorrow morning, so last night, I "packed" up my photo files. Last year, we had sunsets, views over the water, and beach residents, mostly under a few inches of water. This year, because we hit a two-week period of extreme low tides, we walked over beaches that we waded on last year, and took photos of the low intertidal zone. We have no real sunsets, very few "blue" photos, a few birds, and hundreds upon hundreds of intertidal organisms.

I'll be blogging critters for weeks.

For now, here's a pair of sea cucumbers, found at the very edge of the water (a bit over 2 feet on the tide table: the lowest this week was 1 1/2 feet):


Cucumaria miniata, the red sea cucumber.

This was a bright brick-orange, and had the feel of a purple starfish; leathery and cool, with scratchy bumps. When I picked it up, it squirted water out of one end and stiffened up.

It is a relative of starfish, an echinoderm. (The name means "prickly skin".) Think of it as a starfish grabbed by the centre top and oral disc at the bottom and pulled into a tube. It has the same five rows of tube feet,an internal skeleton (no spine, though) and the same colours as our purple starfish; orange, brown, purple or pinkish; most are orange.

Another, found under a rock, and looking, before I dug it out, like the arm of a starfish, was fatter and longer:


6-inch long sea cucumber.

The deep red patch at the upper end is the oral disc; when the cucumber is feeding, it will extend 10 red tentacles, which sweep through the water, catching tiny bits of decomposing organic matter.

Like the other, it squirted water when I picked it up, then stiffened; I could see the fat mid-section contract. These sea cucumbers have a water-based vascular system, which serves as our blood does, for transporting food and oxygen, but as well is used to power the tube feet. The water it squirts out is not part of this system; it comes from the intestine.

Note: internet connection has been spotty; I may not log in until we stop in Powell River tomorrow night. Those five questions and "tagees" will wait until we're home.

2 comments:

  1. I caught one on my line once while fishing off some rocks. I am sure I snagged it rather than it getting on my line by itself. I sent it home to enjoy another day. - Margy

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  2. I've never seen one in real life. Someday I hope I do! They sound fascinating.

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