Why is this fish so dumb?
Good God, man! It's a giant snail vacuum mouth of death, coming at you very, very slowly - just move! All you have to do is ... anything! Nope. OK, you did nothing.
What looks like a case of natural selection weeding out those fish without any common sense or athletic ability is evidently a case of chemical warfare. This species of snail, Conus tulipa, belongs to a group of predatory snails(1) that uses neurotoxins to immobilize and then overtake prey. The problem is, most of them use a poison dart like this:
Clearly that's not what's going on with C. tulipa. It's just a giant, obvious, excruciatingly slow, net-mouth coming right at the slimy little bug-eyed fish face - and that video is sped up! Because we are busy people who don't have time to watch this sort of slow-motion train wreck at its true glacial speed.
But, OK, it's not hard to imagine that instead of darting them with a neurotoxin, they are releasing it in the water nearby before they "spring the trap". And that's what people thought for a while. A recent paper(2) shows that the fish aren't the victims of a toxin, but a hormone. Fish are sent into hypoglycemic shock as C. tulipa releases an insulin into the surrounding water. This, according to WebMD, is likely to cause confusion, dizziness, sweaty skin, and "feeling shaky" in the fish. No, I'm kidding. Fish can't sweat. This is what it does to fish:
You just witnessed actual science! So the idea is the insulin makes fish susceptible to the snails' otherwise unambitious attack strategy. One of the other cool things is that, because there are many different forms of insulin, snails had to evolve an insulin that would work on fish!
If snails have taught me nothing, it's that there's more than one way to skin a fish. And that it's totally fine to be lazy as long as you have a sweet chemical arsenal.
References and Miscellany:(1) Don't you dare act shocked that there is such a thing as predatory snails! Did you not read the very first thing I ever published on this blog?! Pay attention, people.
(2) Actually, as of the writing of this post, it's not even published - just a preview still.