Clownfish live in a group, which consists of non-breeding males and one male and female breeding pair.
If something happens to the female, its male will change sex and become the group’s female replacement.
Image via Wiki Commons
This deep sea species (and fellow “Finding Nemo” star) is known for its unusual appearance, but it’s quickly gaining notoriety for having one of the strangest mating rituals in the animal kingdom. Male anglerfish are significantly smaller than their female counterparts.
Once two anglerfish hit it off, the male will bite into the female, releasing an enzyme that permanently fuses them together. The male then becomes a parasitic lump of sperm attached to the female. When the female is ready to release her eggs, the male provides the sperm she needs to fertilize them. A female can have more than just one parasitic male attached to her at a time!
Poison Dart Frogs
Male poison dart frogs attract mates through an elaborate ritual that includes distinctive vocalizations. Some species of poison dart frogs will fight each other to impress prospective females!