During each mating season, the relatively puny male anglerfish feverishly scurry to find a mate. They appeal to the relatively large female anglerfish with a fair degree of passion. If the female approves of the male’s advances, then he’s going to get lucky. However, the anglerfish’s definition of lucky differs from ours. You see, during sex, the female anglerfish absorbs the male anglerfish into her body.
Essentially, the male anglerfish becomes a sperm-providing extension of the female. When the female is ready to spawn, she has a mate immediately available.