Behavioral and Reproductive Strategies of Porcellio Species (Oniscidea) in Tunisian Pre-Desert Ecosystems

Abstract

Oniscids inhabiting xeric habitats are of particular interest because these habitats may be one of the important agents for desert soil fertility. Although numerous studies have examined the relationship between the environment and population ecology in wood- lice that live in mesic habitats, very little is known about these desert species. Tunisia is known for its arid regions south of the Tunisian Dorsal, habitats in which several species of terrestrial isopods are well adapted. Porcellio is the most widely represented within these habitats: their species richness reaches eight in arid bioclimatic stage. The most widespread of the Porcellio is P. buddelundi , and the least widespread is P. albicornis. Behavioral and reproductive studies carried out in Zarat and Matmata on the two spe- cies P. albinus and P. buddelundi showed that the xeric Porcellio species are mainly active at night and they shelter from the extreme heat and dryness of their habitats either in burrows they dig or by vertical migration. The reproductive pattern is seasonal with two breeding seasons. Life history traits allow P. buddelundi to be an r-strategist and P. albinus a k-strategist. The latter displays a fairly developed social behavior, which allowed him to be the most evolved of Porcellio.