The morphology and potential function of mechanoreceptors found on members of the family Coenobitidae

The mechanoreceptors of land-dwelling juveniles of the family Coenobitidae were studied using scanning electron microscopy to determine how their morphology varied from the mechanoreceptors of the marine dwelling zoea stage. Archived specimens of Birgus latro Leach, 1816 and Coenobita clypeatus Latreille, 1829 from the collections maintained in the National Museum of Natural History, Smithsonian Institution were examined. The mechanoreceptors on the antennules of the planktonic marine larval stage, zoea, are potentially capable of detecting near field sound energy at frequencies two orders of magnitude lower than those of the antennules of the land-dwelling juveniles in both genera. This sensitivity to lower frequencies potentially enables the larval stages to detect sound energy sources at much greater distances.