Despite the name, sea spiders aren’t actually spiders (though, that’ll likely be of little comfort to an arachnophobe). Although they look remarkably similar, sea spiders have a thinner cephalothorax than their eight-legged land-based lookalikes, and their legs tend to have more joints. Because this isotope is rare in nature, the researchers could track its impact on the sea spiders, including if it was ingested. They found that methylotrophic bacteria located on the sea spiders’ exoskeletons served as a source of a food. “While the deep sea feels really far away, all organisms are interconnected,” Goffredi told CNN.