Determination of temperature preference and the role of the enlarged cheliped in thermoregulation in male sand fiddler crabs, Uca pugilator

1.Male Uca pugilator whose major cheliped was immersed in 3 °C water bath experienced a significant drop in Tb. Thus, the enlarged claw of male Uca pugilator may have an unexplored function: thermoregulation.2.Crabs prefer warmer substrates (19-24 and 28-30 °C) over cooler (15-17 °C).3.Mean selected temperature (MST) may not be an accurate reflection of Tb. Crabs in a thermal chamber preferred temperatures between 25 and 30 °C but their average Tb was 23.2 °C.