The "kids exhibit" (that's what I'm going to call it, not sure what it's actually called) at Osaka Aquarium. Oh boy where to start with this one. First of all the theming is just hideous. All the tanks are just bare sand with marbles, beads, hideous fake plants and plastic toys as decoration. Secondly the tanks are entirely unsuitable for the species they hold, most tanks are far too small (several Pea Puffers in what is basically a fishbowl, Common Lobster which takes up half of the floor area in it's tank, and generally small tanks for active species like tangs) with zero hiding places for the fish, and picky grazing species like Mandarinfish and Moorish Idol have zero live rock on which to graze (the Mandarinfish was reduced to picking at a tiny spot of the tank bottom without sand that had encrusting algae growing on it). Porcupine Puffers looked gaunt and malnourished.
Also the Ringed Seal and Rockhopper Penguin exhibist, also at Osaka Aquarium, are both far too small, with not enough water to swim (About 2 metres by 3 metres by 1.5 metres I would say for the seals, and one seal is extremely overweight. Penguin pool is very shallow, the penguins can only just fully submerge, and is about a metre wide and 3 or 4 metres long. Both exhibits have low walls which allows visitors to easily reach in and touch the animals). Shark and ray touch pool is not much better, far too small for the larger rays, very crowded, animals have nowhere to escape the handling and to top it all off, the exhibit is completely unsupervised. Just a very disappointing end to an otherwise fantastic aquarium.