Hepatozoon cf. terzii (Sambon & Seligman, 1907) infection in the snake boa constrictor constrictor from north Brazil: transmission to the mosquito Culex quinquefasciatus and the lizard Tropidurus torquatus.

Specimens of Hepatozoon-infected Boa constrictor constrictor were obtained from localities in Pará State, north Brazil. Gametocytes in erythrocytes of the peripheral blood measured 10 x 2.5-16.2 x 3.7 microns. They were similar to those described as Haemogregarina terzii by Sambon & Seligmann (1907) in B. c. constrictor, in that they did not distort the infected erythrocyte, and their dimensions approximated those given by Carini (1947). Lungs and liver of infected snakes contained actively dividing meronts of a single type, and cysts containing two to six cystozoites were also present in the liver. Our initial feeding of Culex quinquefasciatus on infected snakes consistently resulted in a heavy death-rate of the engorged mosquitoes, with only a few surviving till the 9th day post feeding. These contained numerous oocysts which were undivided or in early stages of division. A fifth and final experiment, however, provided a few mosquitoes surviving up to 21 days post infection (dpi), and these contained fully sporulated oocysts measuring 190-200 microns in diameter and containing over 60 sporocysts of 19-30 microns in diameter. The number of sporozoites in each sporocyst was estimated as approximately 50. The nature of the parasite's sporogonic cycle in the mosquito thus justifies inclusion of this haemogregarine in the genus Hepatozoon. Two wild-caught specimens of the lizard Tropidurus torquatus were fed with mosquitoes containing fully developed oocysts (21 dpi). When sacrificed, three months later, large numbers of dizoic, tetrazoic and hexazoic cysts were demonstrated in their livers. Cystozoites released from these cysts were shown to possess a conspicuous refractile body.

Ultrastructural studies on the sporogony of Hepatozoon spp. in Culex quinquefasciatus say, 1823 fed on infected Caiman crocodilus and Boa constrictor from northern Brazil.

Laboratory reared Culex quinquefasciatus Say, 1823 originating from the vicinity of Belem, in northern Brazil, were allowed to engorge on caimans (Caiman c. crocodilus) infected with Hepatozoon caimani (Carini, 1909) and boas (Boa constrictor) infected with H. cf. terzii (Sambon and Seligmann, 1907) both from Para State. Engorged mosquitoes killed on successive days post-feeding (p.f.) were studied by transmission electron microscopy. Images of oocysts from 13 days p.f., caiman-fed mosquitoes were also examined by scanning electron microscopy. The Hepatozoon spp. from the respective hosts differed in their ability to develop in C. quinquefasciatus. Most female mosquitoes fed on caimans, became fully engorged, and survived beyond 22 days p.f., whereas those engorged on boa became debilitated and did not survive beyond 9 days p.f. In boa-fed mosquitoes oocysts were found on the 6th day p.f. The few mosquitoes surviving to the 9th day p.f. contained either undivided oocysts or those that had already commenced sporogenic division. By 8-10 days p.f. caiman-fed mosquitoes contained uninucleate oocysts. Sporogonic divisions were observed from day 12 p.f. onwards. Although sporogenic development conformed in general with the previously reported accounts, the study allowed a more detailed examination of the plasmalemmal endocytotic system, and the consolidation of the crystalline body in specialized 'factories' of cystalline material. Sporozoite differentiation occasionally started on the 18th day p.f., but otherwise was observed only on day 22 p.f.

Light microscopical structure and ultrastructure of a Besnoitia sp. in the naturally infected lizard Ameiva ameiva (Teiidae) from north Brazil, and in experimentally infected mice.

A Besnoitia species of the teiid lizard Ameiva ameiva (L.), from north Brazil was established in laboratory mice and hamster by the intraperitoneal inoculation of bradyzoites in the tissue cysts. In the lizards all the cyst wall layers were closely apposed. In the mice the layers of the wall were distinguishable, and ultrastructurally the inner cytoplasmic layer contained either a tight network of endoplasmic reticulum or packed mitochondria or both. These components were less frequent or sparse in the inner cytoplasmic layer of cysts in the lizard. The only animals available for experiments in attempts to indicate the definitive host of the parasite were 3 kittens of the domestic cat and a juvenile specimen of the snake Boa constrictor raised in captivity. No evidence of infection could be detected in these animals after feeding them with the tissues of mice harbouring cysts with very large number of bradyzoites.

Karyomegaly in Baryancistrus sp. (Loricaridae) from Amazonian Brazil.

Vesicular karyomegaly of the liver hepatocytes is described from Baryancistrus sp. (Loricaridae), in 3 out of 7 fish, collected from Rio Xingu in central Amazonian (neutral water) Brazil and kept about 2 wk in a holding facility fed with acid water (pH 5.0 to 5.5). Altered cells also occurred in the gill epithelium. The vesicles in the liver were shown to contain a periodic acid-Schiff (PAS)-positive substance or residue.

Plasmodium kentropyxi n.sp. (Apicomplexa: Haemosporina: Plasmodiidae) and a Plasmodium tropiduri-like parasite in the lizard Kentropyx calcarata (Lacertilia: Teiidae) in north Brazil.

Plasmodium kentropyxi n.sp. is described in the teiid lizard Kentropyx calcarata from north Brazil. Young asexual stages and gametocytes are at first polar in the erythrocyte but with elongation, move to a lateral position. Largest meronts seen contained from 30-40 nuclei and conspicuous greenish-black pigment granules located in a distinct vacuole. With growth the gametocytes eventually assume a smooth, curved cylindrical shape, with evenly rounded ends. Pigment is scattered or concentrated around a conspicuous vacuole which is slowly developed as the gametocytes mature. Mature male parasites measured 11.8 x 4.0 microns (9.6 x 4.2 - 13.2 x 3.6 microns), shape-index 2.9 (2.2 - 5.0), and females 13.5 x 4.5 microns (12.0 x 4.5 - 15.0 x 4.8 microns), shape-index 3.0 (2.2 - 3.8). Some larger meronts may slightly enlarge the erythrocyte, but most asexual stages and the mature gametocytes rarely do so. A second, P. tropiduri-like parasite encountered in K. calcarata possessed small rounded or fan-shaped meronts producing from 4-14 merozoites, and spherical to subspherical gametocytes of approximately 6.0 x 5.0 microns. The parasite was consistently polar in its position in the erythrocyte.

Kidney sphaerosporosis with extrasporogonic stages in the blood in Baryancistrus sp. (Loricaridae) from Amazonian Brazil.

Examined fish of the genus Baryancistrus (Loricaridae) from Rio Xingu in central amazonian Brazil were found infected with extrasporogonic stages of Sphaerospora sp. (Myxosporea) in the blood and sporogonic stages in the glomeruli with the resulting escape of the sporogony products into the renal tubules, apparently when the mesangial tissue in the Bowman's capsule collapsed. Spores were seen evacuating via the urinary tubules. Blood stages were initially 2.1 x 2.8 to 2.8 x 2.8 microns in size, and when fully differentiated reached 5.6 x 5.6-5.6 x 7.0 microns; in blood smears they were 11.2 x 8.4 to 14 x 8.4 microns. Bisporoblasts in the glomerular taft were 9.8 x 7.0 microns, premature spores were 5.6 x 4.2-5.6 microns.

Ultrastructural study of meronts and gamonts of Choleoeimeria rochalimai (Apicomplexa: Eimeriidae) developing in the gall bladder of the gecko Hemidactylus mabouia from Brazil.

Endogenous development of Choleoeimeria rochalimai (Carini et Pinto, 1926) Lainson et Paperna, 1999 in the gall bladder of Hemidactylus mabouia (Moreau de Jonnes, 1818) from Belém, Brazil is reported at the fine structural level. Meronts and gamonts develop in the epithelial cells of the gall bladder. Infected cells become enlarged and displaced above the epithelial layer. Developing merozoites, dividing meronts and succession of developing microgamonts from initial nuclear division up to final microgamete differentiation are described. In addition towall forming bodies, mature macrogamonts possess a large inclusion or cisterna with fine granular contents.

The fine structure of the endogenous stages of Isospora hemidactyli Carini, 1936 in the Gecko Hemidactylus mabouia from North Brazil.

The ultrastructure is described of the meronts, microgamonts and young oocyst stages of Isospora hemidactyli of the gecko Hemidactylus mabouia from Belém, PA, north Brazil. The endogenous stages all develop in the nucleus of the gut epithelial cells. The nucleus remains intact up to the latest stages of the parasite's development, but degenerates by the time the oocyst appears. Merogonic division appears to be asynchronous, and some of the differentiated merozoites contained more than one nucleus. Microgamonts conform in structure with those of other eimeriids. Some of the type 2 wall-forming bodies disintegrate into smaller globules and ground substance of lower density.

The fine structure of the endogenous stages of Isospora hemidactyli carini, 1936 in the gecko Hemidactylus mabouia from North Brazil

The ultrastructure is described of the meronts, microgamonts and young oocyst stages of Isospora hemidactyli of the gecko Hemidactylus mabouia from Belém, PA, north Brazil. The endogenous stages all develop in the nucleus of the gut epithelial cells. The nucleus remains intact up to the latest stages of the parasite's development, but degenerates by the time the oocyst appears. Merogonic division appears to be asynchronous, and some of the differentiated merozoites contained more than one nucleus. Microgamonts conform in structure with those of other eimeriids. Some of the type 2 wall-forming bodies disintegrate into smaller globules and ground substance of lower density.

The life-cycle and ultrastructure of Sarcocystis ameivamastigodryasi n. sp., in the lizard Ameiva ameiva (Teiidae) and the snake Mastigodryas bifossatus (Colubridae).

Sarcocysts in muscles of the teiid lizard Ameiva ameiva from north Brazil were fed to the colubrid snake Mastigodryas bifossatus, the faeces of which had been shown to be devoid of coccidial oocysts or sporocysts. When necropsied 16 days later the snake was shown to have developed a massive intestinal infection of Sarcocystis. Mature sporocysts from another, naturally infected M. bifossatus were fed to juvenile specimens of A. ameiva in which no sarcocysts could be detected in tail muscle biopsies. When examined 30 and 47 days later they had very large numbers of sarcocysts in their tail and tongue muscles. The parasite is given the name of Sarcocystis ameivamastigodryasi n. sp. An ultrastructural study has been made of the sarcocyst and of the parasite's sporulation in the lamina propria of the snake: the latter provides details of the wall formation process in developing sporocysts. Attempts to infect a specimen of the boid Boa constrictor constrictor by feeding it with infected Ameiva failed, suggesting that sporocysts previously recorded in genera of the family Boidae may be those of a different species of Sarcocystis.

The ultrastructure of some endogenous stages of the coccidian Eimeria boveroi Carini & Pinto, 1926 in the gut epithelial cells of the gecko Hemidactylus mabouia from Brazil.

The ultrastructure of intracytoplasmic meronts and macrogamonts of Eimeria s.l. boveroi in the small intestine of the gekkonid lizard Hemidactylus mabouia from Belem, Para north Brazil is described. Young meronts, and some of the fully grown macrogamonts, are coated with a glycocalyx which, in cross-section, has the appearance of a series of fine tubules. The wall of the parasitophorous vacuole (PV) is a single membrane, lined on the host-cytoplasm side with an endoplasmic reticulum (ER) which sometimes expands into large cisternae filled with electron-lucent, globular material. The membranal edges of the ER, canaliculi and cisternae have regularly spaced indentations filled with an electron-dense substance. Vesicular mitochondria are present in addition to those of the conventional type. Macrogamonts develop the characteristic type 1 and type 2 wall-forming bodies, and in some zygotes the cisternae containing the latter are grossly expanded. Both types of wall-forming bodies persist in young oocysts that have a distinct oocyst wall.

Re-descriptions of Isospora ameivae Carini, 1932 in the teiid lizard Ameiva ameiva and isospora hemidactyli Carini, 1936 in the gecko Hemidactylus mabouia, with particular reference to their endogenous stages.

Redescriptions are given of the mature oocysts of Isospora ameivae Carini, 1932, from the teiid lizard Ameiva ameiva, and Isospora hemidactyli Carini,1936 from the gecko Hemidactylus mabouia, in north Brazil. The endogenous stages of the two parasites in the small intestine are described. Those of I. ameivae are intracytoplasmic, whereas those of I. hemidactyli are intranuclear.

Re-descriptions of Isospora ameivae Carini, 1932 in the Teiid Lizard Ameiva ameiva and Isospora hemidactyli Carini, 1936 in the Gecko Hemidactylus mabouia, with Particular Reference to their Endogenous Stages

Redescriptions are given of the mature oocysts of Isospora ameivae Carini, 1932, from the teiid lizard Ameiva ameiva, and Isospora hemidactyli Carini,1936 from the gecko Hemidactylus mabouia, in north Brazil. The endogenous stages of the two parasites in the small intestine are described. Those of I. ameivae are intracytoplasmic, whereas those of I. hemidactyli are intranuclear

Some coccidia from the gall-bladder and intestine of the teiid lizard Ameiva ameiva ameiva and the gecko Hemidactylus mabouia in north Brazil.

A study has been made of the endogenous development of two eimeriid Coccidia in the teiid lizard Ameiva ameiva, which were previously considered by Carini (1932) to be conspecific with Eimeria rochalimai and Eimeria boveroi Carini & Pinto, 1926, described in the gecko Hemidactylus mabouia. It has been shown that this is not so, and the two parasites of A. ameiva have been named Choleoeimeria carinii n. sp. and Acroeimeria pintoi n. sp. A description is also given of the endogenous stages of the two eimeriid coccidians previously described in Hemidactylus mabouia. The one from the gall-bladder is renamed Choleoeimeria rochalimai (Carini & Pinto, 1926) nov. comb., and a redescription is made of Eimeria boveroi. The shortcomings of diagnosis based solely on morphology of the oocysts are discussed, particularly with regards the eimeriids of reptiles.

Schellackia (Apicomplexa: Eimeriidae) of the brazilian tree-frog, Phrynohyas venulosa (Amphibia: Anura) from Amazonian Brazil

Endogenous stages of a Schellackia species are described in histological sections of the intestine of the tree-frog, Phrynohyas venulosa, from North Brazil. Most oocysts sporulate within the epithelial cells of the gut, but a few were detected in the lamina propria.

An erythrocytic virus of the brazilian tree-frog, Phrynohyas venulosa

Blood erythrocytes of Brazilian tree-frogs, Phrynohyas venulosa were found to frequently contain single, small, densely staining inclusions. Electron microscopy showed these to be icosahedral viral particles which measured from 250-280 nm in diameter; they were devoid of an envelope, and thus differed from previously described viruses of frog erythrocytes. The infected erythrocytes lacked a crystalline body.

An erythrocytic virus of the Brazilian tree-frog, Phrynohyas venulosa.

Blood erythrocytes of Brazilian tree-frogs, Phrynohyas venulosa were found to frequently contain single, small, densely staining inclusions. Electron microscopy showed these to be icosahedral viral particles which measured from 250-280 nm in diameter: they were devoid of an envelope, and thus differed from previously described viruses of frog erythrocytes. The infected erythrocytes lacked a crystalline body.