Skin-derived semiochemicals of the lacertid lizard Acanthodactylus boskianus

Abstract

Skin lipids impede transcutaneous water loss in several species of squamate reptiles and act as a barrier to harmful microorganisms; they play an additional role as chemical cues involved in chemical communication eliciting behavioral responses in intra- and interspecific interactions. While studies till now give little detailed information on the nature of skin slough, the femoral gland secretions of the lacertid lizardAcanthodactylus boskianushave been analyzed and the chemical profile is known for the species. In the present study we use GC-MS analysis of skin slough to focus on the chemical composition of skin in the xeric-adapted lacertid lizardA. boskianusand compare this to its femoral secretions. In the shed skin we detected steroids, alcohols, carboxylic acids, alkanes, aldehydes, carboxylic acid esters, squalene, monoglycerides of fatty acids, glycerol monoethers of long chain alcohols, and 1,3 alkanediol, which are the same chemical groups already found in the femoral secretions of this species. However, the relative percentages of these compounds in skin slough differ from those known for femoral secretions. While the compounds characterizing skin slough are qualitatively similar to femoral secretions, they could represent an adaptation to hot and dry habitats ofA. boskianus. With regard to the characteristic chemical profiles for different sexes, there is not enough evidence to support their possible role as chemosignals, and behavioral experiments should be performed to test the possible use of skin shedding in intraspecific communication.