Love hurts. Literally, for nudibranchs (also known as sea slugs). Some species prepare for mating by stabbing each other!
In a practice known as traumatic secretion transfer, nudibranchs will stab their partners with a syringe-like appendage called a penile stylet. This injects their partners with sex hormones, preparing both nudibranchs for mating (both take part in the stabbing!).
What do these hormones do, exactly? Scientists still aren’t sure. Some scientists theorize they may inhibit the sperm of rivals—or increase the potency of their own! Ouch.
All clownfish are born male, but not all clownfish stay that way. The bigger and more dominant a clownfish is, the more likely it is to transition to female—a state from which it cannot return.
A single female clownfish presides over a harem of males, and she’ll only mate with the largest, most dominant male. If the female dies, her erstwhile partner will himself transition to female and take up her mantle as leader of the school!
Deep Sea Anglerfish
Some species of anglerfish live in total darkness, in extremely deep waters where it isn’t easy to find a mate. As a result, they practice one of the most intense forms of monogamy out there.
When the much smaller male anglerfish encounters a female, he wastes no time … biting into her side and holding on for dear (and ever-lasting) life.
Overtime, the male anglerfish’s lips fuse to his mate, connecting to her bloodstream. Eventually, he loses all of his internal organs…except those vital for mating.
You and your partner may love dancing, but we promise, it’s got nothing on the seahorse.
Seahorse couples greet each day with specially choreographed dances, designed to strengthen their bond. They’ll twine their tails together and move about, changing color as they bob and weave.
There’s more to this dance than fun and bonding, though—it also helps a seahorse assess if its partner is ready to mate!