Image source
Previously:

Convergence
Stupid Design
Weird Evolution
The Axolotl
Mutual Symbiosis
Parasitic Symbiosis Part 1
Parasitic Symbiosis Part 2
Deception

Sex is terrifying.

If you arrogantly scoff at that, then you don’t know sex. Okay you might know HUMAN sex, which can be scary in itself, but we’ve mostly gotten used to it over millions of years. It’s all about perspective.

Or maybe not. Maybe there’s just some sexual reproduction that is objectively scary. I’ll start with the tame stuff and we’ll take a darker turn as we go. Brace yourselves.

Asexual reproduction

Oh, you thought I was talking about sexual reproduction? Well yes, but with one exception. We should look at the Komodo Dragon.

For those who don’t know, Asexual reproduction is essentially one-parent sex. Bacteria divide themselves into two, and even whiptail lizards manage without any males to begin with.

The mighty Komodo Dragon, however, can actually make use of both forms of reproduction, depending on conditions at the time. Famously, the dragon named Flora is isolated from any males in her captive London Zoo home. Clearly the desire to have babies is too strong in dragons though, since she bore 25 fertilized eggs anyway, 11 of which survived.

How? Well, during meiosis, four potential eggs, or progenitor cells, are released, and one of those can become an egg. For the dragon, another one of those reject cells is repurposed as a surrogate sperm cell which then fuses with the primary egg.

This process only produces male offspring, however, meaning any colony formed this way would require the children to constantly mate with their own mother, which would create a bottleneck in genetic diversity and all the inbreeding issues that comes with it.

There are actually many organisms that can reproduce in both methods; starfish, aphids, slime molds and so on, but the Komodo is by far the biggest, and coolest.

Hermaphrodites

For this one, video is worth a thousand words, and you should seriously take the time to watch these leopard slugs, to the tune of David Attenborough:

For those who can’t watch, the leopard slugs get together, climb up and hang off a tree branch, dangle off a rope of mucus, spin around each other in an hour of foreplay, release each of their over-sized penises from their heads, form a blue, glowing globe of penis, exchange each other’s sperm and the process is finally complete. Take that, Karma Sutra.

But the leopard slug isn’t even the strangest in the slug world…

The banana slug essentially does the same thing, but with the added feature of chewing both of their genitals off in the process. This is possibly a way to reduce competition from other sperm donors, but nobody really quite knows for sure. I mean for a start, once one begins chewing, the other returns the favour. Weird.

Sexual cannibalism

If eating each other’s penises isn’t filling enough, how about your entire mate? Typically, if you go looking for this stuff, you’ll see female spiders and mantis do this. The females need the sustenance for the kids, and the fathers are more than happy to oblige… Very weird.

But in the case of the wolf spider, the males occasionally eat older females, because they’re no longer useful for breeding and it would be a shame to waste such good protein. Chivalry is dead.

Female spiders aren’t to be outdone, however. The females of Wolf spiders, along with up to 15% of other spider species, raise the stakes even higher, with ‘pre-copulatory sexual cannibalism’ – eating the male BEFORE they have sex. That’s not to say they somehow have sex afterwards (though that can and does happen, as we will soon learn), but when there are a lot of males competing against each other in the area, eating the first few that come up to you is no big deal – plenty more fish in the sea. And at the same time, lots of protein for the kids!

Deceptive cannibalism

So I also mentioned the mantis. These girls can be even more devious, actually lying about their health and fertility to males in order to grab a meal. Basically, when a female is ready for sex, she unleashes pheromones that bring the males to them. The pheromones signal certain information like how healthy she is.

If a female is starving, however, she will make her pheromones signal that she is even more fertile, attracting even more males than usual. The eager males rush straight to her with the promise of sex, only to be gobbled up by their very short-lived partner.

Freakishly, this isn’t enough to deter some of the guys. While the female typically rips the head of the males first, the guys have another kind-of brain in their abdomen, more than enough brain power to mate with her anyway, regardless of health. Now isn’t that nice? One starving cannibal and one headless corpse setting aside their differences for the greater good.

Source

Suicide sex

Not just something you can find in the Dark Web, killing yourself with sex is actually completely natural in some corners of the world.

As soon as it’s time, the marsupial mouse, antechinus get ready to mate. The males have sealed their fate. They’re ready. This is it. The race is on for all males to mate with as many females as possible in two weeks. The entire neigbourhood is fair game.

Each antechinus will likely mate with each female during this time, with little time to eat or sleep.

Obviously not eating, not sleeping and banging constantly is going to have some health risks, and this is demonstrably proven by the antechinus, which wears itself out to death during this time. In the long run, like the wolf spider, this lowers competition for food, so the babies have a higher chance of survival.

Bees possibly have it worse.

Right when the male is about to climax after getting busy with the Queen, his genitals explode, instantly killing him. He gets the last laugh though, because now his broken penis is stuck inside her, preventing any other males coming in and scooping his sperm out – as you do.

Rape

Rape is somewhat of a human construct. Whether a female consents or not isn’t really an issue called into question in nature; if the male is physically capable, he'll do anything to get it done. But some take it to extremes. To read more about face-raping culture, or Traumatic insemination in nature, visit fellow Steemian @hugmug here for interesting insight.

In a way, some animals are even worse than that. Friendly cute dolphins, for example, turn to gang rape. And ducks? Male ducks are so sexually aggressive that it even shows in the male-female evolutionary arms race. The males have devised a ritual in which they attack and peck at a female until she accepts his penis or she dies from peckicide. Not much of a choice.

So, females devised a corkscrew-shaped vagina in response, allowing her to block sperm she doesn’t want once inseminated. Of course, failing to find a mate isn’t the end for male ducks; they’ll not hesitate to turn to males, or failing that, dead ducks.