Lots of different exhibits, some trivial (the first one, "Japanese forest", with a couple of sleeping otters and a bunch of plants), some huge (the Pacific ocean tank.) A highlight of this aquarium is that it's very deep: you go up to the top, and the top of various exhibits -- e.g. penguins, seals, and dolphins -- and then you spiral down, and see underwater levels of those exhibits, going down quite a ways. Some aren't too exciting, like the giant kelp of the Aleutian islands (still, informative), while for others you see diving penguins, seals, and dolphins...
There are a couple of odd ones, like the ring-tailed coati, which I don't think is even aquatic at all, or the capybara, which does eat riverside grass but still.
The penguin one had king penguins, gentoos, and Adelie penguins. The kings stood around looking big and yellow-stained, while a couple of Adelies were playing quite energetically in the water, or jumping out and diving in again. Their exhibit was full of actual ice, including ice bits continually dropping from a hole in the ceiling; some kings stood under it and apparently didn't mind ice whacking them on the head.
There were a couple of Pacific whitesided dolphins, quite active, without many people around; the Japanese seem to prefer penguins to dolphins.
The Pacific tank is Big and has Many Animals, in particular two whale sharks, I'd guess around 6 meters long (based largely on a painting in a shopping area later). Quite impressive. Also hammerheads and various others, large manta or sting rays, schools of mackerel, etc.
A cafeteria sold me a fishcake sandwich, and provided actual paper napkins, contradicting my experience and testimony so far.
A deeper tank had giant spider crabs. Lots of them, very large. Very creepy.
I grew up hearing that sharks and rays had to keep moving in order to breathe. There were a whole bunch of bamboo sharks resting at the bottom of the Pacific tank, gills moving without their bodies going anywhere, so I guess not. They weren't just scattered around, but there was a whole cluster of sharks and other fish in a corner. I have no idea if they were being social or if there's something attractive about that corner of the tank.
(AMNH says some sharks do have to keep moving, others don't; all do have to keep moving to avoid sinking to the bottom.)
I'd gotten there at 14:48, and made a second pass starting around 18:00. The puffins seemed more active, swimming around, while six sea lions had all gone to sleep on wooden platforms, and cuddling; one seal was resting elsewhere, while another was still frolicking. I had previously no idea there were more than one seal and two sea lions.
The "Seto inland sea" tank had lots of things, including a cluster of one fish species all resting together, and octopi mostly in pots. One was moving around, apparently trying pots, which were occupied.
There's a room of jellyfish that's pretty cool. Some are small and plain, some are elaborately pretty.
I had a couple of train mishaps. One on the way, which I don't recall -- I think I got on the wrong line for the route I'd planned or someting. And on the way back, I got off at Hommachi, when I needed to get off at Saikasuji Hommachi. Happily, a different line also went from there to my home stop. Less happily, it took 2-3 minutes of walking, probably why Google suggested the other route.
Osaka has some sort of free municipal wifi portal. I haven't tried using it yet.
See the DW comments at https://mindstalk.dreamwidth.org/525096.html#comments