Saurian Malarial Parasites in Eastern Panama

Under the light: high prevalence of haemoparasites in lizards (Reptilia: Squamata) from Central Amazonia revealed by microscopy

Blood samples from 330 lizards of 19 species were collected to investigate the occurrence of haemoparasites. Samplings were performed in areas of upland (terra-firme) forest adjacent to Manaus municipality, Amazonas, Brazil. Blood parasites were detected in 220 (66%) lizards of 12 species and comprised four major groups: Apicomplexa (including haemogregarines, piroplasms, and haemosporidians), trypanosomatids, microfilarid nematodes and viral or bacterial organisms. Order Haemosporida had the highest prevalence, with 118 (35%) animals from 11 species. For lizard species, Uranoscodon superciliosus was the most parasitised host, with 103 (87%; n = 118) positive individuals. This species also presented the highest parasite diversity, with the occurrence of six taxa. Despite the difficulties attributed by many authors regarding the use of morphological characters for taxonomic resolution of haemoparasites, our low-cost approach using light microscopy recorded a high prevalence and diversity of blood parasite taxa in a relatively small number of host species. This report is the first survey of haemoparasites in lizards in the study region. It revealed a high diversity of lizard haemoparasites and highlights the need to understand their impacts on hosts.

Saurian malaria in Kenya: epidemiological features of malarial infections in lizard populations of the West Pokot District

During investigations into the prevalence of malarial parasites among lizards in the West Pokot District in Kenya, 179 lizards comprising eight species were caught. Examination of the Giemsa-stained smears made from their blood showed that 34 lizards were infected with Plasmodium species. Fifteen lizards were infected with a single species of Plasmodium and 19 carried multiple infections, the maximum, in four lizards, was four species. There were 19 combinations of parasite infections. Seventeen Plasmodium species were identified, the commonest being P. icipeensis. Only two of the eight lizard species were infected: the skink Mabuya striata and the agamid Agama agama. Eight of the Plasmodium species infected both; another eight species infected M. striata only but three of these have been described from different lizard families elsewhere in Africa. P. robinsoni infected A. agama only, although it was first described from another lizard family in another part of Africa. The epidemiological significance of these results is discussed.

Observations on non-pigmented haemosporidia of Brazilian lizards, including a new species of Saurocytozoon in Mabuya mabouya (Scincidae)

Of 63 specimens of the lizardMabuya mabouya(Scincidae) examined in Pará State, Brazil, 31 showed one or more haemosporidians in the peripheral blood. These includedGarnia(Plasmodium)morula(Telford, 1970), Lainson, Landau & Shaw, 1971;Plasmodium tropiduriandP. diploglossiAragão & Neiva, 1909; aPlasmodiumspecies close toP. diminutivumTelford, 1973a; and a new species ofSaurocytozoonLainson & Shaw, 1969a. Eleven different combinations of these parasites were noted, emphasizing the care needed in avoiding erroneous descriptions based on mixed infections. This is especially so whenG. morulais mixed withP. tropidurior other species with small, rounded gametocytes occupying a polar position in the red blood cells. Of 18 skinks infected withG. morula, 10 had pure infections, as judged by repeated examinations over long periods. The morphology of the Brazilian parasite is very similar to that described forG. morulafrom Panama (Telford, 1970): no malarial pigment could be demonstrated in any stage of the infection, including ookinetes and possible early oocysts which were studied in experimentally infectedCulex pipiens fatigans. Ookinetes and rounded forms, possibly representing uninucleate oocysts, persisted in these insects up to 24 h after the blood-meal, but developed no further.C. p. fatigansis thus unlikely to be a natural vector ofG. morula. Saurocytozoon mabuyisp.nov. is described inM. mabouya: the gametocytes develop in the lymphocytes and monocytes of the circulating blood and reach maximum size in 19–28 days. The parasite can be distinguished from the other known species,S. tupinambiof the teiid lizardTupinambus nigropunctatus, by its smaller gametocytes. Nothing is known of the sporogonic cycle. Differences between the sporogonic stages ofS. tupinambiandLeucocytozoonare listed.