So we all know that pretty much all cephalopods can shoot ink as a self defense method, but are there any other sea critters that practice "defensive secretion"? I know there are some sea hares that do it, and obviously most animals on earth produce some form of fluid, but I was wondering if there are any other creatures that do it at the same levels as cephalopods. Googling this question is very hard.
Besides hagfish making huge clouds of slime that suffocates predators, there's a bunch of deep sea creatures that release luminescent clouds! The best known is a shrimp:
There's also sea cucumbers that can release a cloud of toxic slime and likely quite a few others. There's also at least one case of an *offensive* chemical cloud; some cone snails release a cloud of insulin to paralyze nearby fish. It's invisible but works almost instantly, sending them into shock. Then the snail can take all the time it needs to swallow them in its big giant stretchy mouth:















