Why Are Male Spiders Willing To Sacrifice Their Lives For Mating?
When it comes to humans, dating and romantic relationships can sometimes become messy affairs. Sometimes cheating is involved, or a restraining order may become necessary, but at least humans do not have to sacrifice themselves to their mate. As we all know, this is what many different types of spiders do regularly. The relatively small sized male will approach the female knowing that its chances of being eaten may outweigh its chances of mating. However, this is just the way it is in the spider world, and many male spiders don’t seem to mind this arrangement. Many researchers have witnessed willing self-sacrifice among some types of male spiders. So why don’t male spiders seem to mind ending their lives? You would think that an instinct for self-preservation would take over when a male spider is being approached by a ravenous female? Yet many male spiders literally roll directly into the female’s mouthparts.
One type of spider that is notorious for sacrificing itself for an opportunity to mate is the Australian red back spider. This spider, as mentioned above, will prepare for its own demise by summersaulting into the fangs of a female. Also, Honeybees offer up a good example of how insects, like spiders, also indulge in sexual cannibalism. Male honeybees have evolved explosive sexual organs. Once a male finds a female, his reproductive organs will explode, which often results in fertilization. Some ants are also known to resort to sexual cannibalism. For example, the type of ant that is known as Dinoponera quadriceps will kill her male partner by dismembering his sexual organ. This results in the death of the male, and a keepsake for the female.
Researchers are not certain as to why male spiders are so willing to sacrifice their lives for mating, but many believe that self-sacrifice is a necessary method in order to introduce a greater number of males into the population. The bodies of the male spiders may even be nutritious to the developing offspring, so females will consume the males in order to properly nourish their offspring. These types of nutrients are known as “somatic nutrients”, and they could also be necessary to optimize the physical fitness and/or number of spider offspring, which could be another motivator for male self-sacrifice. In any case, the next time you are involved in a dramatic breakup, just be thankful that you are not a spider.
Can you think of any other reason why it would be evolutionarily advantageous for male spiders to allow themselves to be eaten by female spiders?