Eimeria lepidosirenis n.sp. (Apicomplexa: Eimeriidae) of the South American lungfish Lepidosiren paradoxa (Osteichthyes: Dipnoi) from Amazonian Brazil

ABSTRACT

The mature oocysts of Eimeria lepidosirenis n.sp. are described in faeces removed from the lower region of the intestine of a single specimen of the South American lungfish Lepidosiren paradoxa, from Belém, state of Pará, Amazonian Brazil. Oocysts with endogenous sporulation spherical to slightly subspherical, 30.8 Î 30.3 µm (28.1 Î 25.9 -33.3 Î 31.8), shape-index (ratio length/width) 1.0, n = 25. Oocyst wall a very thin, single layer approximately 0.74 µm thick, smooth, colourless, with no micropyle and rapidly breaking down to release the sporocysts. Oocyst residuum a bulky ovoid to spherical mass of approximately 20.0 Î 15 µm , composed of fine granules and larger globules and enclosed by a very fine membrane no polar bodies seen. Sporocysts 15.5 Î 9.0 µm (14.5 Î 8.0 16.0 Î 9.0), shape index 1.7 (1.6-1.8), n = 30, ovoid, with one extremity rather pointed and with a very delicate Stieda body but no sub-Stieda body sporocyst wall a single extremely thin layer with no valves. Sporocyst residuum a spherical to ovoid mass of approximately 5.0 Î 4.0 µm, composed of fine granules and small globules and enclosed by a very fine membrane. Sporozoites strongly recurved at their ends and apparently with only a single refractile body. Site of development in the host uncertain no evidence of endogenous stages was found in fresh scrapings and stained smears of the intestinal epithelium.