I’ve written before about crazy inventive parasites which would go to impressive lengths to grab a snack from their favourite host. Today though, I’m writing about a true parasitic love story. Many great poets and novelists had written love stories when impossible love becomes possible for the sole effort of the two people involved. This love story though is as true as any love story could get and it’s the sole reason for a whole species to persist for millions of years. It’s also different from other parasite stories I’ve written about before because this is about interspecies parasitism.
Deep dive into the sea
To understand the characters of this story, we need to go deep. Very deep into the ocean. In fact, we need to go five times deeper than any human can dive and survive it. The heroes of this story can be found as deep as 1,5 kilometers. There, where it’s perpetual darkness, once in awhile we get to see a blip of light. That light comes from the illicium of the anglerfish. It can serve many purposes. It can be a bait, it can also be a warning – depending how big the seer of the light is. Some deep ocean habitants will swim away from it as fast as they can, because they know it signifies something hungry and with big teeth. Others will mistake it for one of the many bioluminescent small breakfast bites and might very well come breakfast themselves. This little blip of light though, if seen by a male anglerfish, is the ultimate booty call. And once he sees that light he makes the best out of charming up the female, because he might not get another chance and he will probably die.
Love put to the test
The solitude of the anglerfish is daunting. So deep into the sea, few species survive and the density of populations is quite low. The main biomass of the sea is the plankton on which most aquatic animals feed. But this plankton often depends on direct sunlight and thus, can’t easily be found deeper than 200 meters under the surface (surely not the photosynthesising algae). This, combined with the uncomprehensible vastness of the open seas, makes bigger animals in general extremely rare.
Grabbing life for the horns
When the chances to meet the love of your life (or any individual of the opposite sex at all) are as low as they are for this species of fish, one must make the best effort to try and grab their attention. And this is where the male anglerfish decided not to leave anything to chance. Instead of having elaborate mating rituals, which might in turn prove futile and he ends up being rejected, he just grabs on and never lets go – literally.
Two become one...
When a male anglerfish finds a female, he bites into her body and starts producing an enzyme which degrades her skin and the skin of his own mouth (!). This allows them to fuse as deep as their blood vessels and essentially become one! This way, the male can receive nutrients from the female – on his own he’d be too small and often with ill equipped jaws to catch prey. And in return, he provides sperm for the female to be able to fertilise her eggs and ultimately make anglerfish babies. What’s even more striking is that some of the female individuals found have not one but few males attached to them.
With all due respect to the anglerfish
In all fairness, one can argue that the mating cycle of the anglerfish is based on symbiosis and not parasitism. But if those were human, and he was getting his food, his sexy time and his butt cruised through the deep sea, that would’ve been 100% classified as parasitism, hence my more liberal inclusion of the anglerfish in this series of posts.