GASTROINTESTINAL DIGENETIC TREMATODES OF RIDLEY,OLIVE TURTLE (LEPIDOCHELYS-OLIVACEA) FROM OAXACA, MEXICO - TAXONOMY AND INFRACOMMUNITY STRUCTURE

Thirty-two Olive Ridley's turtles (Lepidochelys olivacea Eschsholtz) w ere collected from the coast of Oaxaca, Mixico, and their digestive tr acts were examined for helminths, Eight digenetic trematode species we re found in the digestive tracts of 24 of 32 turtles: Adenogaster seri alis, Himasomum lobatus, Pyelosomum renicapite (Pronocephalidae), Pach ypsolus irroratus (Pachypsolidae), Enodiotrema megachondrus (Plagiorch iidae), Orchidasma amphiorchis (Telorchiidae), Prosorchis psenopsis (H emiuridae), and Calycades anthos (Calycodidae). Oaxaca represents a ne w locality for all digenean species and L. olivacea represents a new h ost record for all except O. amphiorchis. Adenogaster serialis was the species with the highest prevalence of infection (53.1%), while E. me gachondrus showed the highest abundance (28.2 digeneans/analyzed host) . Digenean community structure at the infracommunity level is depauper ate and isolationist according to the values of species richness, numb ers of worms, and diversity. Vagility, and the possibility of a mixtur e of populations arriving at the nesting site, as well as broad feedin g preferences, are suggested as the main factors that determine the di genean community structure in L. olivacea.