Wood detection by the marine isopod Limnoria.markup
S M Henderson, S M Cragg, A J Pitman
The search for alternative control methods for Limnoria, should perhaps focus on the most vulnerable stage during the isopod life cycle - during dispersal when adulls leave their tunnels to find new wood. Dispersal is known to be triggered by environmental conditions, although how Limnoria locate fresh wood is unknown. Literature available on Limnoria dispersal, their sensory capabilities during dispersal and colonisation of new wood, suggests that chemoreceptors and mechanoreceptors are the most likely sense organs used during dispersal and wood attack. Evidence for the detection of wood by Limnoria using distance chemoreception is lacking, though there is some evidence for contact chemoreception. A preliminary research programme involving behaviour experiments, light microscopy, scanning and transmission electron microscopy to determine how Limnoria detect wood is presented. Behaviour results show that antenna 1 and antenna 2 are used in functionally different ways, suggesting each pair of antennae are responsible for a different sensory modality. Contact chemoreceptors on the second antennae and olfactory sense organs on the first antennae may be responsible for detecting wood. Both the uropods and ventral edge of Limnoria telson are in constant contact with the surface of wood during crawling and are therefore ideal locations for sense organs.