Prevalence and intensity of the blood parasite Hemolivia mariae in a field population of the skink Tiliqua rugosa

Abstract

The impacts of virulent parasites on humans or domestic animals are well documented. Less is known of the impact of parasites in natural host-parasite associations. A population of the Australian sleepy lizard Tiliqua rugosa is infected with the blood microparasite Hemolivia mariae, which is transmitted by the ectoparasitic tick Amblyomma limbatum. In most infected lizards a very small proportion, usually < 1%, of red blood cells are infected. A study of the prevalence of the microparasite in the field population found no difference either over 5 years of study or among times within a lizard activity season. Juvenile and sub-adult lizards and larger adults were less frequently infected with H. mariae than were other adults. In sub-adults this was related to a lower level of tick infestation. In adults, male and female lizards were equally frequently infected with H. mariae, but the presence or absence of ticks was not predictive of infection. The lizards' body condition was measured as the residual of the regression of log snout-vent length against log body mass. In female lizards the body condition was not affected by infection. In males the body condition declined over the sampling period each year, probably as a result of mate attendance. The body condition was poorer in male lizards with H. mariae infection than in uninfected males. Possible explanations for the associations of microparasites and host lizards are discussed.

Ecology and Dynamics of the Blood Parasite, Hepatozoon Tuatarae (Apicomplexa), in Tuatara (Sphenodon Punctatus) on Stephens Island, New Zealand

“…Although it is possible that seasonal variation in Ht occurred outside of our sampling times, this temporal stability in infection is consistent with other studies of Hepatozoon (Salkeld and Schwarzkopf, 2005;Santos et al, 2005) and other haemogregarine bloodparasite infections in reptiles (Bromwich and Schall, 1986;Smallridge and Bull, 2000;Amo et al, 2004;Š iroky et al, 2004;Amo et al, 2005). The temporal stability could be influenced by the long-lived nature of blood-parasite infections in reptiles, with some lizards remaining infected for 17 (Smallridge and Bull, 2001) to 18 mo (Salkeld and Schwarzkopf, 2005). One tuatara in our study was infected in consecutive samples that were collected during an 18-mo period, suggesting the potential for a similar longevity in tuatara blood-parasite infections.…”

“…In both species, infection levels are lowest among larger (older) adults, either because resistance to infection increases with exposure to infection and age, or because only fit and resistant individuals survive to reach an old age (Smallridge and Bull, 2000;Madsen et al, 2005). In extremely longlived hosts, like tuatara, this poses a potential problem for the parasite, which needs to survive in a host population where the pool of susceptible hosts does not have a rapid turnover.…”

Prevalence of Hemolivia mauritanica (Apicomplexa: Adeleina: Haemogregarinidae) in natural populations of tortoises of the genus Testudo in the east Mediterranean region

“…Our field data suggest a high prevalence of H. mauritanica, at least in some natural populations of tortoises, upon comparison with data from Smallridge and Bull (2000) on the prevalence of Hemolivia mariae Smallridge et Paperna, 1997 in field populations of the Australian sleepy lizard Tiliqua rugosa (Gray, 1825). This fact could be explained by the longterm persistence of parasitaemia by H. mauritanica in naturally and experimentally infected tortoises (Široký et al 2004).…”

The Effect of Host Foraging Ecology on the Prevalence and Intensity of Coccidian Infection in Wild Passerine Birds

“…Fewer studies, however, had the objective to recognize and follow pathogenic elements, including parasites that can be harmful only to birds. Knowing and following the prevalence and intensity of parasitic infection in any animal species may be important for future studies evaluating how global climate change may have infl uenced rates of parasites ' prevalence (Tompkins andBegon 1999, Smallridge andBull 2000). In the recent study by Lawson et al (2011), trichomonosis was identifi ed as a newly emerging signifi cant disease in greenfi nch Carduelis chloris population in England and continental Europe.…”