Two new species of Haemocystidium Castellani & Willey (Apicomplexa: Plasmodiidae) from Pakistani lizards, and the support their meronts provide for the validity of the genus

Abstract

Haemocystidium papernai n. sp., a parasite of Agama nupta fusca in Sind, Pakistan produces large halteridial gametocytes in active infections that do not differ in morphology by sex. In chronic phase macrogametocytes are larger than microgametocytes. In Baluchistan, Agama nupta nupta is parasitised by Haemocystidium quettaensis n. sp. Gametocytes are smaller than those of H. papernai n. sp., round or oval in shape and heavily pigmented. Macrogametocytes are larger than microgametocytes and more heavily pigmented. Merogony of H. papernai n. sp. occurs in endothelium and connective tissue of lungs, heart, liver, spleen and femoral muscles. Meronts form as oval or rounded bodies that apparently are not preceded by the formation of “pseudocytomeres” that appear in the merogony of Haemoproteus spp. in snakes, turtles and birds. Meronts of Haemocystidium kopki were found in the lungs of the Pakistani gecko Teratoscincus scincus that were similar to those of H. papernai n. sp. The meronts of both species closely resemble phanerozoic meronts of saurian Plasmodium spp., and provide adequate justification for recognition of the genus Haemocystidium Castellani & Willey, 1904. Haemocystidium is distinguished from Plasmodium by the absence of an asexual cycle in circulating blood cells, and from Haemoproteus by meronts that do not form as pseudocytomeres. Sex ratios of H. papernai n. sp. varied from 22–47% microgametocytes, with no evident correlation with parasitemia, infection stage or month of collection, and H. kopki infections were comprised of 61–74% microgametocytes.