No abstract

In many animals, chemical signals play an important role in species recognition and may contribute to reproductive isolation and speciation. The Iberian lizards of the genus Podarcis, with up to nine currently recognized lineages that are often sympatric, are highly chemosensory and provide an excellent model for the study of chemically mediated species recognition in closely related taxa. In this study, we tested the ability of male and female lizards of two sister species with widely overlapping distribution ranges (Podarcis bocagei and P. hispanica type 1) to discriminate between conspecific and heterospecific mates by using only substrate-borne chemical cues. We scored the number of tongue flicks directed at the paper substrate by each individual in a terrarium previously occupied by a conspecific or a heterospecific lizard of the opposite sex. Results show that males of P. bocagei and P. hispanica type 1 are capable of discriminating chemically between conspecifics and heterospecifics of the opposite sex, but females are not. These results suggest that differences in female, but not male, chemical cues may underlie species recognition and contribute to reproductive isolation in these species. The apparent inability of females to discriminate conspecific from heterospecific males, which is not because of reduced baseline exploration rates, is discussed in the context of sexual selection theory and species discrimination.

A survey of gastrointestinal helminth communities of Podarcis bocagei and Podarcis carbonelli (Sauria: Lacertidae) from NW Portugal was conducted to determine the prevalence, intensity and diversity of intestinal parasites in these lizards. A few parasite species were found in both hosts, their prevalences, mean intensities and abundances of infection being low or very low. Low values of richness and abundance of parasite species were also found in the helminth infracommunities of individuals of both host species. These low values of parameters of infection and diversity are discussed and compared between both host species and among other Iberian lacertid lizards.

A parasitological survey was carried out to determine the relationships between helminth fauna and some biological traits of two host species of lacertid lizards. Size, sex, diet, and season of collection, as well as infracommunities and component communities of Podarcis bocagei and P. carbonelli from Douro litoral (northwest Portugal), have been analysed. In both host species, we found low values of parasite infection parameters and diversity. These findings were in accordance with their feeding habits, eating only animal prey and no plant matter. Evidences suggest a relationship between the presence of Brachylaima sp (Trematoda: Brachylaimidae) and the ingestion of snails by both lizard species. Spauligodon carbonelli (Nematoda, Pharyngodonidae), a specialist in Podarcis hosts, was the most important parasite, affecting mainly adult males with a prevalence of infection showing seasonal variation.