Preying mantids show sexual cannibalism, biting off the heads of their male counterparts during mating. But don't worry! Losing their heads doesn’t stop their reflexes, so mating can continue until the very end. Females who consume the males have been found to have higher levels of male-derived amino acids in their tissues and eggs, compared to those that didn’t. This can actually increase female fecundity and fertility! This kind of mating is commonly seen in captive mantids, probably because the male is unable to escape its surroundings. Whereas in the wild, this is rarely seen as the male is able to escape, unharmed.
But not all murderous mating ends in the female eating the male. Sometimes, the female can even sacrifice herself for her young. The Desert Spider (Stegidyphus lineatus) is one of these mothers who gives her own life to nourish her children! First, she regurgitates liquid food for her young, then 2 weeks later…the young eats the mother! But things gets more unusual! Studies have shown that those females who are immature/infertile can act as nest helpers, also regurgitating food and giving her own life to the young of another female spider!
Preying mantids show sexual cannibalism, biting off the heads of their males counterparts during mating
Other animals turn into zombies. The sockeye salmon, found in the Pacific ocean, releases eggs and sperm into the water. Sounds pretty harmless, right? Well, once the sockeyes spawn, their body condition starts to deteriorate. Their skin goes grey and sheds away, leaving a suitable place for fungus to colonise. Fungus spreads to their skin lesions and the sockeyes salmon rot alive. These “zombie fish” then decease, leaving their reproductive gametes and skeleton behind…
And finally, you may think brown antechinus are cute and fluffy, but the males’ mating ends in disaster! Mating season is intense for these brown fluffballs, lasting only 1-2 weeks. Larger males with the larger testicles are more likely to outcompete competitors, to win females and to produce more sperm. But this advantage causes males to die soon after mating, as levels of testosterone and cortisol in their blood skyrocket. High cortisol destroys the muscle protein and suppresses immune system responses eventually leading to death. The hormones which made male successful during mating, sadly backfire in the end, killing them.
