It's called a Water Scorpion. It's an actual bug (Hemiptera). The "whip" is what they breathe through, by poking it through the water's surface. They can fly too, which seems unlikely when you see them in the water like this. I've only ever seen one fly once, and I thought it was a big beetle crashing into a puddle - but it turned out to be a Water Scorpion landing.
That's cool, thanks! I like all these invertebrates and you see lots of cool things in the rainforest, but I really know so little about them that I hardly know where to start.
It's a bit embarrassing how much my knowledge drops off outside birds and mammals. Especially since if you round it, all animal species are invertebrates. (I think that might be a Dawkins line?)
One of the benefits of being a "naturalist" rather than a pure birder or mammal-watcher is that there is always something interesting to see. If you go out spotlighting and don't see any lorises (possibly a foreign concept for you) there are still all sorts of cool invertebrates which you see along the way. I've met quite a few birders who showed zero interest in any animal which isn't a bird, and I find that bizarre.
I don't really know much about invertebrates either, other than the general identities. There are some that I know to species, but mostly it is "water scorpion", "stick insect", "big scary spider", etc. It is kind of nice not being under self-pressure to need an identity for them all though, like there is for birds and mammals.
