2017-06-15 11:08:45 UTC
Saying that the pirate spider has evolved a specific toxin designed to knock out specifically the other spider, but rather less toxic to other animals
It asks how and why such a strange hunting strategy could have evolved.
Well, I think I know the answer to that question, having observed spiders in my house, tiny ones.
I have observed that when no food is available they move out of their orb and move to some where else. Often where there are other like spiders of the same species. And if no food is available, they end up going to the orbs of their neighbors and fighting each other and one eaten.
So, it is easy to see how a species of spider eaters can evolve from regular spiders once the food supply is restricted. Once that food is rare, and moving does not help, then, it ends up as cannibalism. The spiders of that species, best able to fight it out to the death, passes those behavior traits to its offspring.
So, it is easy to see this "Pirate behavior" formed in every species of spiders, when the food supply is rare and the only food available, are, other spiders, then you become a pirate.
So I bet that if the researchers in pirate spiders set up a single species, not pirate species, and then the food supply becomes rare, that those spiders will wander to another orb to fight to the death.
And it maybe the case that a species of just eating other spiders is not a species but just a hybrid form.
The spiders in my house are fine delicate, little bodies with very long legs. They love light, and where there is one there are usually 4 or 5 next to them. And they visit one another, so as the food supply never materializes, they eat each other.