Relationships between helminth communities and diet in Canarian lizards: the evidence from Gallotia atlantica (Squamata: Lacertidae)

Abstract

Diet and helminth fauna were analysed in the lizard Gallotia atlantica (Squamata: Lacertidae), the smallest species of this genus endemic to Lanzarote and Fuerteventura (Canary Islands), in an attempt to confirm previous claims of relationships between these ecological traits in this genus. A total of 70 lizards belonging to the subspecies atlantica (central southern Lanzarote), laurae (northern Lanzarote) and mahoratae (Fuerteventura) were examined. Compared with other Gallotia, the helminth fauna was impoverished, particularly in Fuerteventura, where the absence of larval cestodes suggests low predation pressure. Diet was omnivorous, the plant fraction (73.03–84.26%) included seeds and fruits while the animal fraction was quite diverse, at least in Lanzarote. Contrary to other Gallotia, the intestinal Pharyngodonidae nematodes were all typical of carnivorous reptiles. An individual association between the complexities of helminth communities and diet reinforces previous findings in other Gallotia species suggesting functional relationships between parasites and prey items inside the digestive tract.

Keywords:

• Canary Islands
• helminth community
• diet composition
• diet-parasites relationship
• Lacertidae

Acknowledgements

This study was funded by the projects PB98-1450 of DGCYT (Spain), and PTDC/BIA-BDE/67678/2006 and PTDC/BIA-BEC/101256/2008 of FCT (Portugal) and partially by project “Biodiversity, Ecology and Global Change” co-financed by North Portugal Regional Operational Programme 2007/2013 (ON.2–O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). FJ was funded through a doctoral grant (SFRH/BD/77332/2011) of FCT (Portugal). Thanks are due to A. Montori, X. Santos and A. Perera for field assistance. Collecting permits were provided by Viceconsejería de Medio Ambiente del Gobierno de Canarias and the Cabildos Insulares (island governments) of Fuerteventura and Lanzarote. Thanks are also due to two anonymous reviewers for their suggestions on an earlier version of the manuscript and to D.J. Harris and B. Presswell for linguistic revision.