OBSERVATIONS ON THE BEHAVIOR, SALINITY RELATIONS AND COLOR CHANCE OF LIGIA-ITALICA FROM MADEIRA

Ligia italica Fabricius is a day-active isopod on the shores of Madeira. The population migrates up and down the shore with the tide, browsing on Lichens and macroalgae. Shore bird predation is negligible; foraging wall lizards are the only daytime predators. Ligia italica retreats into crevices at night. It exploits plant material within supralittoral and intertidal pools and enters pools with salinities as high as 74 parts per thousand. Ligia italica emerges from pools at intervals to breathe in air; such emersion lasts no more than two minutes. Ligia italica on Madeira has no colour change ability, the isopods remaining dark grey/black whatever the background.