>>282241162
The caption originally said "この世の豆知識". この世 (konoyo) means "this world". This is a direct counterpart to a あの世 (anoyo), which means "the other world" and refers to the afterlife both in this series and in general. The specific caption talking about the clione also referred to it as a sea creature of this world.

Clione is apparently a genus of sea angels, which are a type of sea slug.