If you're a Valentine's Day cynic...
...then angler fish species, like those in the family Ceratiidae, are right up your alley!
Close-up of male anglerfish fused to the female's back.
(Photo: Dr. Theodore W. Pietsch, University of Washington)
Because these deep-sea dwellers are rare, it can be hard for them to find a mate. So once a male angler fish finds a mate, he never wants to let her go. But his method of keeping the love alive may not seem all that romantic. Among angler fish, all sizable individuals are female and most have what appear to be parasites attached. It turns out that these "parasites" are actually tiny males! Male ceratioids live solely to find a mate using their extremely well-developed olfactory organs. Once he finds a female, the male bites into her skin and releases an enzyme that causes their blood vessels to fuse! The male body slowly atrophies, becoming not much more than a pair of gonads, which release sperm in response to female egg release. This extreme sexual dimorphism
ensures that, when the female is ready to spawn, her mate is always there. Too bad she can't count on him for much else.
Underwater conga line...
Sea hares are hermaphrodites. In other words, they are equipped with both male and female reproductive parts. These animals are virtually blind, and must rely on chemical communication via pheromones to find each other and mate. They live alone most of the time, but when it is time to mate, watch out! During the mating season they congregate in massive orgies, forming "mating chains" of multiple individuals. In these chains, the gastropod at the front plays the role of female, the one at the end male, and all the others in-between play both roles. In this way the sea hares can both receive sperm and pass their own to a third party. These guys are truly the swingers of the deep!
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Giving it all up for love...
The Argonauts, or paper nautilus, are a group of octopi like no other. After mating with a male, who is around 8 times smaller, a female secretes her shell, lays her eggs within the structure, and climbs in herself. Joining her inside is the male sex organ, or hectocotylus
, that has snapped off and been abandoned during mating - OUCH! Not to worry, though. Males regrow a new hectocotylus every year.
Queen for a day?
Clownfish reproductive roles change over time- the largest fish is the female
(Photo: J.E.Randall via FishBase)
Many fish species, such as clownfish, wrasses, and moray eels change gender (including reproductive functions), during their lifetime. This is a normal anatomical process called sequential hermaphroditism. The best known examples are clownfish species (think "Finding Nemo") with a social hierarchy based entirely on body size. The largest fish in a group is female. When she dies, the most dominant male in the group changes sex and takes her place.
So if you think love is confusing for people, just think of our fishy friends and take heart. It could be a lot worse!
Click here to explore even more bizarre mating rituals!