You know it’s serious science fiction if there’s a dude who’s literally just a fish.
The Little Mermaid is serious science fiction, apparently.
You know The Little Mermaid is serious science fiction because it’s about a daring
young xenoanthropologist whose radical theories about alien cultures put her at odds with the reactionary isolationism of her society’s ruling class. Having a dude who’s literally just a fish is a bonus.