Spiders are born with the minimum brain mass they need to be able to function, which is still a substantial amount, especially considering the size of some of the tinier spider species. Researchers measured the central nervous systems of nine species of spiders ( for example: the pachygnatha clercki), from rainforest giants to spiders smaller than a pin head in Panama and Costa Rica not long ago. They found that as the spiders get smaller their brains get proportionally bigger and so fill up more and more of their bodies. The nature has found a way to shrink neurons and other brain cells to as small a size as they need.This discovery was made as part of ongoing research to understand the link between a creature’s size and its brain size and behavior. The smaller the animal, the more it has to invest in its brain, which means even very tiny spiders are able to weave a web and perform other fairly complex behaviors.
No matter their size, all spider species have to perform the same basic set of tasks. Some of those behaviors are fairly complex, and that means a sizable part of the body must be given over to brain cells. There’s a lower limit on how small brain cells can be and still function properly, which means miniature spider species have to resort to some pretty unusual biological solutions to fit all their brains in. The spiderling young of some of the smallest species actually have bulging bodies just to contain all their brains, though they grow out of the more extreme deformities. Spiders aren’t generally thought of as particularly smart creatures, but some spiders’ brains are literally too big for their heads. It seems that no matter how big or small a spider’s body is, its brain is always the same size.
Translated by Blue Line