Such ability can pose a great challenge to its prey.
Spiders are known to lead an antisocial and solitary existence. For the most part, they spin webs in strict solitude, living in them and only interacting with others of their species when it is time to mate. However, a team of researchers discovered that some of them have evolved to become social, and that they have done so through shared genetic changes.
In a recent study published in the journal Nature Communications, researchers looked for differences between social and non-social spiders. His work consisted of comparing the genomes of 22 species with a certain degree of sociability. They found evidence of genetic changes that, compared to other spiders, allowed them to be more social. The researchers note that this evolution could pose a challenge to prey, if such social activities involve these insects associating to improve their hunting skills.
Some spiders, including the Australian huntsman, have evolved to become more social, says Alexander Mikheyev, a professor at the Australian National University’s Research School of Biology. “When we think of spiders, we tend to think of the ones that just hang on the web or sit in a corner and kill things,” he says. “But [los individuos de] certain species have evolved independently, in much the same way, to be more social.”
In one species, for example, mothers were found to protect their young from predators. Others, like the Australian hunter, are characterized by sharing food. These examples are known as subsocial behaviors, and are better described as tolerance than displays of sociability, the researchers note. Still, they suggest that they may be signs that some are evolving to be more social.
Previous research has shown that increased sociability is accompanied by changes in the size of certain brain regions and sensory organs. However, arthropods, an order of invertebrates that includes spiders, butterflies, and other insects, do not have brains like humans. Instead, they distribute their neural tissue widely, meaning the brain equivalent can take up space throughout their bodies.
Research shows that social spiders, such as the Australian hunting spider and the African social spider, have more developed nervous systems than solitary species. “A lot of the socialization of these spiders involves sitting together and eating in the same place, or sharing food. It’s a lot like eating as a family,” says Mikheyev. “There’s also a level of kinship, similar to how you’re more social with your family members, as opposed to complete strangers,” he adds.