These spiders have the fastest biological clock seen yet

A species of spiny orb-weaver spider has a 19-hour circadian clock. Photo: ojogabonitoo / iStock

Three species of orb-weaving spiders may have the fastest biological clocks known in nature. Their circadian cycles range between 17.4 and 19.0 hours on average, instead of synchronizing with a 24-hour solar light cycle. The research, conducted at East Tennessee State University, was presented Sunday at the annual meeting of the Society for Neuroscience.

Why it matters: Their clock is so fast, it's unclear how the spiders survive. Studying extreme sleep-wake cycles and circadian clocks can help scientists understand the role these neurological timekeepers play in species survival and what causes our own rhythms to go awry due to disease.