Family identity of the sub-social desert terrestrial isopod Hemilepistus reaumurii

Terrestrial isopods (Oniscidea) are crustaceans whose ancestors have left the water to conquer land even in arid regions where Hemilepistus reaumurii is living. This species is the only terrestrial isopod conducting a real sub-social life as a monogamous semelparous species forming families. The chemical signature of five family units from this population was investigated by gas chromatography. Results showed highly significant differences among the family units according to: (i) the cuticular chemical profiles which confirm that the cuticle is one of the most important organs involved in family chemical signature and recognition; (ii) the cuticular chemical distances and (iii) the faeces chemical profiles which suggest that these droppings help individuals of the same family to find their burrows and deter intruders. Moreover no significant correlation was shown between faeces chemical distance and the distance between burrows from where the family units were collected.