Plasmodium carmelinoi n. sp. (Haemosporida: Plasmodiidae) of the lizard ameiva ameiva (Squamata: Teiidae) in amazonian Brazil

Abstract

Plasmodium carmelinoi n. sp. is described in the teiid lizard Ameiva amelva from north Brazil. Following entry of the merozoltes into the erythrocyte, the young, uninucleated trophozoites are at first tearshaped and already possess a large vacuole: with growth, they may assume an irregular shape, but eventually become spherical or broadly ovoid. The vacuole reduces the cytoplasm of the parasite to a narrow peripheral band in which nucleur division produces a schizont with 8-12 nuclei. At first the dark, brownish-black pigment granules are restricted to this rim of cytoplasm but latterly become conspicuously concentrated within the vucuole. The mature schlzonts are spherical to avoid and predominantly polar in their position in the erythrocyte. They average 5.4 × 4,9 μm (4.4 × 4.4 - 6.6 × 5,9 μm), shape index 1.1, n = 50: 8-1 2 merozoites are produced and measure approximately 2.0 × 1,0 μm. Mature gumetocytes are also polar in position, and spherical to subsphericul. The macrogumetocytes measure 5.7x5,2 μm (4.4x4.0- 5.9 x 5,1 μm), shape Index 1.1, n = 50 and, following staining by Giemsu's method, possess a compuct, pink-stulning nucleus and u cleur blue, faintly stained cytoplusm. Microgumetocytes are slightly larger, 6.0 x 5,0 μm (5.2 x 4.4 - 6.2 x 5,2 μm), shape index 1.2, n = 45. They stuin an overall pink colour due to the dispersed nucleur chromatain. The vacuoles in both the maero- and microgumetocytes are considerably smaller than those of the schizonts and of ovoid or spindle shupe: they contain most of the pigment granules. The sex ratio, as seen in an iniciul intense infection, was 1 male to 2.2 females. Prevalence of Infection was low (5 %) but, due to the very low parusitaemia which may result In u failure to detect parusites, It is probably higher than this.