A classic romance staple features a fiercely independent character who resists vulnerability until a specific partner coaxes them into a domestic partnership, mimicking the transition from a solitary existence to a shared life.

Top 10 most romantic animals - World Animal Protection Canada

In the deep sea, the tiny male anglerfish finds a massive female, bites into her skin, and releases an enzyme that dissolves his own mouth and her flesh, fusing them together at a cellular level. He loses his eyes, his internal organs, and his independence, surviving purely as a sperm-producing parasite attached to her body.