The lizard Podarcis atrata, endemic to the Columbretes archipelago (Mediterranean, Spain) occupies very small islands characterized by extreme aridity and a reduced availability of potential insect prey. The results of an experimental study have shown that adult lizards offered individuals of Ligia italica and Armadillo officinalis (marine and terrestrial isopods, respectively) consumed at high frequencies; with males consuming them at significantly higher frequencies than females. The results are discussed in light of the importance of the inclusion of marine prey into the diet in arid insular ecosystems.