I love sea robins!
Fish, like most animals, are actually really good at learning anything that has to do with one of three topics: (1) what can I eat, (2) what is trying to eat me, and (3) what do I have to do to get laid. So the natives learn about the lionfish, but the lionfish also learn about the spear fishermen. I’m working on a project now where we’re spearing some lionfish, and when we go out it could not be more obvious which populations have been speared recently and which have not. The lionfish in undisturbed populations are bold as can be, caring not one whit that you have a spear cocked literally centimeters from their face. The ones from populations that are fished regularly are all stuffed up under rocks during the day, and you’re just sorta hoping you’ll see a spear-able bit through some hole in the reef.
I’ve actually done a bit of hook and line fishing underwater too (i.e., we’re on scuba and have a reel of line with a hook on it), and the difference there is even cooler; you’ll see fish with mouths too small to hook (wrasses, damsels, etc.) happily swim up and peck-peck-peck away at your bait, while the ones that are hook-able will often swim up, look really closely, and swim away. You can seriously almost see them say “hahaha fuck that, it’s got a hook in it”.
tldr; On the grand scale of things fish aren’t super smart, but when you get in their wheelhouse (food, survival, and sex), they are much more clever than people give them credit for.
