Aquarium is a variety of aquatic animals, can be described as "mixed", please use your "fiery eyes" to point out which of the following is a real group of fishes (

The real fish should have the basic characteristics of fish.

3 seahorses, ⑤ puffer fish, ⑥ Chinese sturgeon, ⑧ belt fish live in the water, breathing with gills, swimming with fins, they all belong to the fish;

① dollfish larvae with gills to breathe, the adult lungs, belong to the amphibian;

② abalone, ④ octopus body soft, belong to the mollusks;

⑦ whale foetal lactation, belong to the mammals.

So, ③ ⑤ ⑥ ⑧ belongs to fish, so C is correct, ABD is wrong.

The choice: C.

These are the most important of all.