Heat makes scuttling tarantulas less coordinated
Texas Brown tarantulas (Aphonopelma hentzi) have two joints in each leg that they need to coordinate while scuttling after prey.
Anna Ahn and I.G. Ros
As the air heats up, tarantulas gain speed but lose coordination in their joints, researchers report April 1 in the Journal of Experimental Biology.
Tarantula legs bend and flex based on hydraulics. Bloodlike fluid called hemolymph flows into the joint to straighten and flows out to flex. Using high-speed video, researchers examined Texas Brown tarantulas (Aphonopelma hentzi) sprinting at progressively higher temperatures: 15, 24, 31 and 40° Celsius.
The tarantulas ran a lot faster at hotter temperatures, but their leg joints became less coordinated. Their swift steps limit the time hemolymph has to flow in and out of the joint.
