Today's discussion at the tide pools is "what's this stuff" I said it looked like some sort of tunicate colony, and was told, no, it's something else, but it's the closest living relative to humans in the sea, and that it's called "sea snot".
This is the problem with common names. "Sea Snot" is generally used to describe marine mucilage caused by algae being overfed by pollution into thick, oxygen sucking masses. It can be compared to red tide, in that it's, in part, an algae bloom. It hit the news in 2021 for blanketing the coast of Turkey.
This is not that, but that's not to say it isn't called "Sea Snot" locally.
Thing is, I'm thinking it might be more commonly called "Sea Vomit". I didn't examine any of it close enough, but iNaturalist has a number of photos of "Sea Vomit" ( Didemnum vexillum) to make me seriously consider that we are looking at the invasive colonial sea squirt.
Tunicates are, in fact, the closest related "invertebrates" to human beings, because they are not, in fact, in phylum: invertebrate, but phylum: chordate (animals with spines) While adult tunicates do not have spines, their larva have a notochord: a cartilaginous "spine" of sorts.
Interestingly enough, this is not the only tunicate which came up in today's discussion. There was a question about "worms" that had washed shore a couple years ago. Those "worms" were not. They were also tunicates... from a group called Salp. I posted a little about them when Cay and I went on her first "Birthday Orca" Whale Watch back in 2019. The photos aren't the greatest, but salp colonies are long chains, which leads some people to think they are some sort of huge marine worm. My daughter wrote a little piece about salp on her blog way back in 2009 for a weekly photo "meme" I ran at the time here at The Radula, and later on it's own page.
It's also possible, since it happened the same year, that what the discussion referred to was these animals, which washed up on California shores the same year: Fat Innkeeper Worms also called Penis Worms or Penis Fish. We saw quite a few of them today on the beach, where they had been dug out of the sand, collateral damage during clamming.
The Fat Innkeeper Worm (Urechis caupo) lives in burrows in the mud in low zone mudflats. Their burrows provide shelter for other animals, which may join them. The ring of setea at one end, clearly visible at one end in my photo, are not around the mouth (which I rather expected, having no experience with this species) but the anus. This are apparently found in several marine and terrestrial species to keep the worm from slipping in their burrow.
I learn something new every day!
More photos from today's tide pool adventure, and more discussion of the animals we saw, at a later date. Tomorrow is Whale Watch, and I need to be well rested!
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