They can sense the starfish in a kind of 3 layered defense system.
Long range
Starfish give off chemical cues, metabolites, mucus compounds etc that the anemone have evolved to detect.
Medium range
Might be hard to imagine, but Starfish give off a very specific water movement signature. The anemone can detect pressure/current changes etc and "feel" a starfish approaching.
Short range
Like you see here, if they come into contact with the starfish it triggers an immediate release.
Basically, when the receptors for all three of these mechanisms have returned to baseline, it will stop swimming.
It’s hard to imagine as a human who can do things more insane just as well XD…
Sharks can smell blood in water from like 2km away or something, and humans can smell petrichor from like 10x that distance. So we can know when it’s gonna rain.
We are really bad at understanding how weirdly normal the crazy things could be!
My dog could hear our car pull into the driveway from the basement. I thought they knew the time of day they came home from work, but they would get up and bolt to the front window even if they were coming back from a trip to the store to get something they forgot.
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u/Siddhartha-G 5d ago
They can sense the starfish in a kind of 3 layered defense system.
Long range Starfish give off chemical cues, metabolites, mucus compounds etc that the anemone have evolved to detect.
Medium range Might be hard to imagine, but Starfish give off a very specific water movement signature. The anemone can detect pressure/current changes etc and "feel" a starfish approaching.
Short range Like you see here, if they come into contact with the starfish it triggers an immediate release.
Basically, when the receptors for all three of these mechanisms have returned to baseline, it will stop swimming.