This changes their camouflage so that they are very well camouflaged against the yellow sand during the day, and dark at night - we think to blend in with shadows on the beach.
Individuals did not change colour when put into dark conditions, but they did become brighter when placed on a white versus a black substrate. Our findings show that ghost crabs have a circadian rhythm of colour change mediating camouflage, which is fine-tuned by adaptation to the background brightness.Read more
Dr Zachary Darnell and Assistant Professor Pablo Munguia tested a bunch of Gulf coast fiddler crabs (Uca Panacea) – both those who still had their major claws and those who had lost theirs.
In the experiment, researchers shone lamps on crabs with an intact major claw and on crabs that were missing theirs.
They measured the crabs' body temperature every 10 minutes and found that the crabs lacking the large claw took much longer to cool down.
Their study focussing on the Gulf coast fiddler crab (Uca Panacea) was recently published in the American Naturalist journal.Read more