Haemogregarine Species Research Articles

Hemogregarine Diversity Infecting Brazilian Turtles with a Description of Six New Species of Haemogregarina (Apicomplexa: Adeleorina: Haemogregarinidae)

(1) Background: Hemoparasites of the genus Haemogregarina (Haemogregarinidae) are commonly reported in freshwater turtles. However, in Brazil, only three species have currently been characterised using molecular methods. This study aimed to bring new insights on the diversity of species of Haemogregarina infecting Brazilian freshwater turtles from Mato Grosso and Goiás states using molecular and morphological tools. (2) Methods: In total, 2 mL of blood was collected, with between two to five blood smears prepared, fixed with absolute methanol, and stained with a 10% Giemsa solution. Blood was stored at −20 °C for molecular analysis targeting the 18S rRNA gene. Fragments of the organs (liver, spleen, heart, and kidney) were separated and stained with hematoxylin-eosin. (3) Results: A total of 40 turtles were screened and hemogregarines were observed in 34 (85%) individuals (3 Podocnemis expansa and 31 Podocnemis unifilis). Haemogregarina embaubali and six new species of Haemogregarina were observed and formally described as follows: H. unifila n. sp., H. rubra n. sp., H. goianensis n. sp., H. araguaiensis n. sp., H. tigrina n. sp., and H. brasiliana n. sp. (4) Conclusions: This study contributes to the diversity and knowledge of Brazilian fresh-water turtle blood parasites, using integrative approaches for diagnosing and characterizing hemoparasites, with the identification of six undescribed species.

Phylogenetic analysis of chelonian hemogregarines reveals shared species among the Amazonian freshwater turtle Podocnemis spp. and provides a description of two new species of Haemogregarina.

This study describes two new species of the genus Haemogregarina living in the Amazonian freshwater turtles Podocnemis expansa and Podocnemis sextuberculata. Haemogregarina species isolated from P. expansa have been characterized by the presence of encapsulated, folded immature gamonts, with the parasitophorous vacuole and fragmented chromatin located in the central region. In Haemogregarina found in P. sextuberculata, curved immature gamonts were observed inside a parasitophorous vacuole, with small, slightly arched meronts with rounded nuclei, and mature gamonts with trapezoid-shaped condensed nuclei. The novel 18S rRNA sequences obtained in this study clustered within a well-supported clade composed of hemogregarines isolated from other neotropical freshwater turtles from the families Podocnemididae and Geoemydidae. The hemogregarines found in this study were compared to Haemogregarina podocnemis from Podocnemis unifilis and Haemogregarina sp. from Podocnemis expansa, based on morphological, morphometric, and molecular data. The analysis supports the new species Haemogregarina karaja sp. nov. isolated from P. expansa and Haemogregarina embaubali sp. nov. found in P. sextuberculata.

Reassignment of Haemogregarina annularis from the Blood of Tarentola annularis to the Genus Hepatozoon Based on the Parasite Morphology and 18S rDNA Sequence Analysis.

To date, two haemogregarines have been described from the white-spotted wall gecko, Tarentola annularis in Egypt. These species are Haemogregarina annularis and Haemogregarina tarentannulari. Although these two species initially were described as different species parasitizing T. annularis, both forms look identical due to their similar morphology and morphometric characteristics from the same host species. Here we will clarify, using traditional morphological description of the blood and tissue stages, combined with molecular analysis, the identity of the haemoparasites infecting T. annularis in Egypt. Thin blood smears were screened from 50 gecko, Tarentola annularis and merognic stages were identified in the lung of the infected geckos. Parasite DNA was extracted and PCR was carried out to amplify parasite 18S rDNA. Morphological criteria of parasite stages, mature gamont stages and mergonic stages were similar to the two previously reported Haemogregarina species. In the phylogenetic tree, the present haemogregarine fell within a clade comprising most of Hepatozoon species infecting reptiles. Our morphological comparison supported that the two previously described Haemogregarina species were the same and allowed us to consider Haemogregarina tarentannulari as a junior synonym of Haemogregarina annularis. Our phylogenetic analysis gave us the opportunity to reassign Haemogregarina annularis to the genus Hepatozoon and being identified as Hepatozoon annularis n. comb.

Characterization and identification of haemogregarine hemoparasites (Apicomplexa: Adeleina: Hepatozoidae) in natural populations of Mauremys leprosa leprosa and M. leprosa saharica from Morocco.

Distribution, prevalence and parasitaemia of apicomplexan parasites of the genus Haemogregarina were studied in 858 freshwater turtles (735 Mauremys leprosa leprosa and 123 Mauremys leprosa saharica) throughout 30 localities from Morocco. Blood smears were collected from the turtles and partial 18S rRNA sequence data used to infer genetic diversity and phylogenetic relationships. Of the 858 individuals analyzed by microscopy 22.7% were infected, from 16 M. leprosa leprosa localities. Individuals of M. leprosa saharica sampled south of the High Atlas Mountains were not infected, probably due to the absence or rarity of the leech vectors in these localities. Within M. leprosa leprosa, we did not identify any patterns between geography and prevalence, which varied between 10% (Oued Nfiss) to 100% (Oued Tassaout). Five distinct genetic lineages were identified, indicating the likely presence of multiple species of haemogregarines, one of which probably corresponds to Haemogregarina stepanowi. Mixed infections were also detected. Additional studies are needed to better understand the ecology and epidemiology of this parasite in turtles, as well as the host-parasite relationship with their definitive hosts, leeches.

Cytochrome c oxydase I phylogenetic analysis of Haemogregarina parasites (Apicomplexa, Coccidia, Eucoccidiorida, Haemogregarinidae) confirms the presence of three distinct species within the freshwater turtles of Tunisia.

Species of Haemogregarina are apicomplexan blood parasites that use vertebrates as intermediate hosts. Due to limited interspecific morphological characters within the genus during the last decade, 18S rRNA gene sequences were widely used for species identification. As coinfection patterns were recently reported from nuclear molecular data for two sympatric freshwater turtles Mauremys leprosa and Emys orbicularis from Tunisia, our objectives were to design COI specific primers to confirm the presence of three distinct species in both host species. Blood samples were collected from 22 turtles, from which DNAs were extracted and used as templates for amplification. Following different rounds of PCR and nested PCR, we designed specific Haemogregarina COI primers that allowed the sequencing of nine distinct haplotypes. Phylogenetic Bayesian analysis revealed the occurrence of three well-differentiated sublineages that clustered together into a single clade. Based on pairwise genetic distances (p-distance), we confirmed the occurrence of three distinct but phylogenetically closely related species coinfecting M. leprosa and E. orbicularis in the same aquatic environments. Our results demonstrate that the use of fast evolving genes within Haemogregarina will help to investigate the parasite diversity within both intermediate vertebrate and definitive invertebrate hosts, and to assess the evolution, historical biogeography and specificity of haemogregarines.

Prevalence and intensity of haemoparasites infecting the white-spotted gecko, Tarentola annularis in Sudan.

Thirty-five white-spotted geckos, Tarentola annularis were collected from Shendi area, River Nile State, Sudan, between June and September 2019 and examined for the presence of haemoparasites infection. Six (17.14%) geckos were found to be positive for intra erythrocytic haemogregarine (Apicomplexa: Haemogregarinidae) species with a mean overall infection intensity of 1.20% ± 0.32 and parasitemia level between ~0.70% and ~1.70%. However, most parasite gamonts were found intracellular, and no damage on the infected erythrocytes was observed. The prevalence of infection between adult and juvenile geckos was significantly different (P = 0.012); however, no substantial difference between males and females was found. On the other hand, the mean intensity of infection did not differ between adult and juvenile geckos. In conclusion, no obvious negative impact on the local T. annularis gecko community was observed due to haemogregarine species infection.

Two Coccidian Parasites and An Unusual Intraerythrocytic Cytoplasmic Vacuolar Inclusion from Agamid Lizard, Trapelus savignii in Egypt

Three types of parasites, two intraerythrocytic and one Isospora species, were recorded to infect lizard Trapelus savignii (Reptilia: Agamidae) collected in summer 2019 from the Eastern Desert in Egypt. The current intraerythrocytic parasites are haemogregarine species and unusual intraerythrocytic cytoplasmic vacuolar inclusions (ICVIs). Blood stages of haemogregarine species are differentiated into three forms; trophozoite, intermediate form, and mature gamont. Trophozoites measure 7.50–8.50 (8.10±0.30) × 2.20–2.40 (2.30±0.06) μm while intermediate forms and mature gamonts measure 7.89–10.39 (9.32±0.85) × 3.9–5.18 (4.32±0.45) and 8.87–12.13 (10.25±0.90) × 2.50–4.35 (3.45± 0.58) μm,respectively. ICVIs are un- or pale-stained with Giemsa and measure 1.62–5.45 (3.64±0.87) × 1.45–5.35 (3.51±1.10) μm. At the ultrastructure level, ICVIs appeared as a membrane-bound electron-lucent matrix and contain three types of materials according to their electron density that may resemble chromatin granules. No nucleus, Golgi apparatus, mitochondria, or any apical complex structure is observed within ICVIs. Effects of haemogregarine species and ICVIs on the infected erythrocytes are recorded. Exogenous and endogenous developmental stages of the present Isospora sp. are described. Sporulated oocysts are mostly spherical, contain bilayered wall, and measure 22.48–27.71 (25.47±1.81) × 21.69–26.91 (24.37±1.73). Oocyst residuum, polar granule and micropyle are absent. Sporocysts are ellipsoidal and measure 13.79–15.84 (14.97±0.67) × 8.80–11.03 (9.97±0.70). Stieda body is nipple-like while sub-Stieda body is absent. Multinucleate meronts contain up to 34 nuclei and measure 6.29–19.83 (11.91±4.58) × 5.43–10.76 (7.57±1.75). Developed microgamonts measure 16.59–18.89 (17.74±0.94) × 15.61–18.63 (17.12±1.24) while mature macrogamonts measure 16.34–24.27 (19.95±2.98) × 12.0–20.28 (16.92±3.22).

The genetic diversity of blood parasites within the freshwater turtles Mauremys leprosa and Emys orbicularis in Tunisia reveals coinfection with Haemogregarina spp.

Haemogregarina species are apicomplexan blood parasites infecting vertebrates such as fish, lizards, and turtles. Due to the high morphological similarity of the erythrocytic stages infecting host species, it has always been a challenge to identify the true diversity of these parasites. Therefore, taxonomic studies are presently based on the combination of morphological and molecular data. In Tunisia, two species of Haemogregarina have been reported within the freshwater turtleMauremys leprosa (Geoemydidae) for more than 40years. Since M. leprosa occurs in the same aquatic environments as Emys orbicularis (Emydidae) in Tunisia, our objectives were to assess parasite diversity and specificity on the basis of both morphological and molecular approaches. The turtles were surveyed and sampled across six aquatic areas of Tunisia. Among the 39 specimens of M. leprosa and seven of E. orbicularis that were trapped and investigated, the presence of haemogregarines was detected in the blood of turtles only at sites where leeches were observed. Three 18S variants were identified, which corresponded to three distinct Haemogregarina species, among which one was identified as Haemogregarina stepanowi. The two other species that were detected are likely new to science. Because we show the occurrence of more than one blood parasite species within a single host specimen, our study provides the first report of coinfection with molecularly distinct Haemogregarina spp.

Blood and Merogonic Stages of Haemogregarina Species Naturally Infecting The Nile Monitor Varanus niloticus, Egypt

Haemogregarines are haemoparasites (Apicomplexa: Adeleiorina) of all class of vertebrates nearly, worldwide. The present study was aimed to establish and describe the developmental stages of a Haemogregarina species infecting Nile monitor (Varanus niloticus). The captured Nile monitors were three animals with 80-100 cm in length, they captured from Qena province, Southern Egypt, and thin blood films were prepared and microscopically examined. Also, small pieces of the liver and the lungs of the infected animals were separated and prepared for sectioning, which stained and examined. The recovered parasites have rod-like bodies, infecting the erythrocytes only, with a single stage, in a parasitophorous vacuole and have no karyolitic effect. The parasitaemia level was found up to 5010,000 counted erythrocytes. Only gamonts have been recognized in blood smears, and they were found in two forms; the first form is short, thick (called short gamont) and measured 11.02 × 2.65 µm. The second form was found long and thin (called long gamont), with a subterminal nucleus, measured 14.18 × 2.45 µm. Both forms cause either slightly or strong displacement of the host cell nucleus. The infected erythrocytes had either slightly or markedly hypertrophied in presence of short and long gamonts. The infected erythrocyte measured 18.05 × 8.87 µm, but the uninfected erythrocyte was 16.52 × 8.77 µm in length and width, respectively. Schizogony phase was observed in the lungs only of the infected Nile monitor, where the meronts were formed within parasitophorous vacuoles. The parasite nucleus divided many times, and the produced nuclei are peripherally arranged in the meront, forming merozoites. After separation of the merozoites, residual bodies formed. The merogonic stages were differentiated into two forms, micromeront that measured 15.57×14.29 µm, and produces a few numbers of macromerozoites, meanwhile the macromeront measured 19×15.9 µm and produces up to six micromerozoites.

Haemogregarina daviesensis sp. nov. (Apicomplexa: Haemogregarinidae) from South American lungfish Lepidosiren paradoxa (Sarcopterygii: Lepidosirenidae) in the eastern Amazon region.

Based on morphology and morphometry of gametocytes in blood and molecular phylogenetic analysis, we described a new species of hemoparasite from the genus Haemogregarina isolated from Lepidosiren paradoxa in the eastern Amazon region. Haemogregarina daviesensis sp. nov. is characterized by monomorphic gametocytes of varying maturity stage and their dimensions were 16 ± 0.12μm (range 13-18) in length and 6 ± 0.97μm (range 5-8) in width. The morphological and morphometric data were not identical with other haemogregarine species from fish. All specimens of L. paradoxa analyzed were infected by H. daviesensis sp. nov. and the parasitemia level was moderate (1-28/2000 blood erythrocytes). Two sequences were obtained from L. paradoxa, and these constituted a monophyletic sister clade to the Haemogregarina species. In addition, H. daviesensis sp. nov. detected here grouped with Haemogregarina sp. sequences isolated from chelonian Macrochelys temminckii, with 99% bootstrap support. This study provides the first data on the molecular phylogeny of an intraerythrocytic haemogregarine of freshwater fish and highlights the importance of obtaining additional information on aspects of the general biology of these hemoparasites in fish populations, in order to achieve correct taxonomic classification.

A paradise for parasites? Seven new haemogregarine species infecting lizards from the Canary Islands.

Oceanic islands are hotspots of biodiversity due to their high levels of endemism, with the Canary Islands being a notable example. A previous molecular study on the biogeography and host associations of haemogregarines (Apicomplexa: Adeleorina) infecting lizards from this archipelago detected seven parasite haplogroups. These haplogroups exhibited high host-specificity and geographical structure, suggesting that they might correspond to distinct biological identities. In this study, along with sequencing a longer fragment of the 18S rRNA, we further explore the distinctiveness of these parasites by analysing their morphology, effects on host erythrocytes and parasitaemia levels. These lines of evidence together with their genetics, host associations, frequency of occurrence and geographical distribution support them as different biological entities. As such, we describe seven new species: Karyolysus canariensis sp. nov., Karyolysus galloti sp. nov., Karyolysus stehlini sp. nov., Karyolysus gomerensis sp. nov., Karyolysus atlanticus sp. nov., Karyolysus tinerfensis sp. nov. and Karyolysus makariogeckonis sp. nov. These new taxa are further examples of endemic diversity in the Canarian archipelago. They also contribute to clarify the taxonomy within the Apicomplexa, a phylum estimated to have one of the lowest percentages of described species.

Two new species of Hepatozoon (Apicomplexa: Hepatozoidae) parasitising species of Philothamnus (Ophidia: Colubridae) from South Africa.

To date, only a few species of Hepatozoon Miller, 1908 have been described from amphibians and reptiles of South Africa, including two species from anuran hosts, three from saurians, one from chelonians, and two from ophidians. Hepatozoon bitis (Fantham, 1925) and Hepatozoon refringens (Sambon et Seligmann, 1907), parasitising Bitis arientans (Merrem) and Pseudoaspis cana (Linnaeus), respectively, were described in the early 1900s and since then there have been no further species of Hepatozoon described from snakes in South Africa. Blood smears, used in peripheral blood haemogregarine stage morphometrics, and whole blood used in molecular characterisation of haemogregarines were collected from the caudal vein of six snakes of three species, namely Philothamnus hoplogaster (Günther), Philothamnus semivariegatus (Smith) and Philothamnus natalensis natalensis (Smith). For comparison, a comprehensive table summarising available information on species of Hepatozoon from African snakes is presented. Haemogregarines found infecting the snakes from the present study were morphologically and molecularly different from any previously described from Africa and are thus here described as Hepatozoon angeladaviesae sp. n. and Hepatozoon cecilhoarei sp. n. Both haemogregarine species were observed to cause considerable dehaemoglobinisation of the host cell, in case of infection with H. angeladaviesae resulting in a characteristic peripheral undulation of the host cell membrane and karyorrhexis. To the authors' knowledge, these are the first haemogregarines parasitising snakes of the genus Philothamnus Smith described using both morphological and molecular characteristics in Africa.

Haemogregarine Genetic Diversity in Captive African Rock Pythons from Nigeria Suggests a Geographical Pattern.

Understanding the processes that drive parasite diversification, distribution, and abundance is central to disentangle the dynamics and evolution of diseases. In this study, we screened African rock pythons from Nigeria for the presence of blood parasites to assess their distribution, diversity, and phylogenetic relationships. A total of 21 captive African rock pythons collected from across 11 locations in Nigeria were sampled between August 2016 and January 2017. Samples were microscopically and genetically analyzed. From the blood smears analyzed, 10 (47.6%) snakes were found to be infected with haemogregarines. Eight of the infected samples were genetically assessed and confirmed as haemogregarines of the recently described Bartazoon group. Two haplotypes were retrieved, of which one was distributed in the northern-central sampled localities and the other in the southern localities. The two haplotypes were clustered in a clade of haemogregarines from snake, gecko, and rodent hosts, and among them, the haemogregarine species Hepatozoon ayorgbor was described from the ball python Python regius. Two haemogregarine haplotypes in Nigerian rock pythons, which appear to have a geographical pattern across the country, were detected in this study.

Monophyly of the species of Hepatozoon (Adeleorina: Hepatozoidae) parasitizing (African) anurans, with the description of three new species from hyperoliid frogs in South Africa.

Haemogregarines (Apicomplexa: Adeleiorina) are a diverse group of haemoparasites reported from almost all vertebrate classes. The most commonly recorded haemogregarines to parasitize anurans are species of Hepatozoon Miller, 1908. To date 16 Hepatozoon species have been described from anurans in Africa, with only a single species, Hepatozoon hyperolli (Hoare, 1932), infecting a member of the Hyperoliidae. Furthermore, only two Hepatozoon species are known from South African anurans, namely Hepatozoon theileri (Laveran, 1905) and Hepatozoon ixoxo Netherlands, Cook and Smit, 2014, from Amietia delalandii (syn. Amietia quecketti) and three Sclerophrys species, respectively. Blood samples were collected from a total of 225 individuals representing nine hyperoliid species from several localities throughout northern KwaZulu-Natal, South Africa. Twenty frogs from three species were found positive for haemogregarines, namely Afrixalus fornasinii (6/14), Hyperolius argus (2/39), and Hyperolius marmoratus (12/74). Based on morphological characteristics, morphometrics and molecular findings three new haemogregarine species, Hepatozoon involucrum Netherlands, Cook and Smit n. sp., Hepatozoon tenuis Netherlands, Cook and Smit n. sp. and Hepatozoon thori Netherlands, Cook and Smit n. sp., are described from hyperoliid hosts. Furthermore, molecular analyses show anuran Hepatozoon species to be a separate monophyletic group, with species isolated from African hosts forming a monophyletic clade within this cluster.

Morphological and molecular characterisation of Haemogregarina sp. (Apicomplexa: Adeleina: Haemogregarinidae) from the blood of the Caspian freshwater turtle Mauremys caspica (Gmelin) (Geoemydidae) in Iran

To date, a number of species of Haemogregarina have been described from different turtle hosts, mainly based on the morphology of the developmental stages detected in the host erythrocytes. The diversity and overlapping morphological features in the old and recent descriptions has led to considerable complications in the taxonomy of Haemogregarina spp. In this study, different stages of maturity and developing gamonts of a putative new species of Haemogregarina were detected in erythrocytes of the Caspian turtle Mauremys caspica (Gmelin) (Geoemydidae) originating from a southern province in Iran. Although some of the morphological characteristics were consistent with Haemogregarina stepanowi Danilewsky, 1885, some new observations were made, particularly in the gamont stage. The phylogenetic analysis based on 18S rDNA sequences revealed that the present isolate appears as basal to a large clade of Haemogregarina spp. with sequences available in the GenBank database. In accordance with the phylogenetic results, the present Iranian isolate showed a higher degree of interspecific divergence (up to 3.3%) compared to the data for the taxa available in the GenBank database. Thus, molecular data indicate that this isolate may represent a new species. However, further genetic analyses are needed as a complementary tool to the morphological characterisation in order to elucidate the phylogenetic relationships of Haemogregarina spp.

First Hemolivia from southern Africa: reassigning chelonian Haemogregarina parvula Dias, 1953 (Adeleorina: Haemogregarinidae) to Hemolivia (Adeleorina: Karyolysidae)

To date, only a single species of Hemolivia, Hemolivia mauritanica (Sergent & Sergent, 1904), has been described from African terrestrial tortoises. Although various haemogregarines have been described from southern African terrapins and tortoises, including species from the genus Haemogregarina and one from the genus Hepatozoon, no species of Hemolivia have been identified previously from southern Africa. Since its morphological redescription, the taxonomic placement of one of these species, Haemogregarina parvula Dias, 1953, was in doubt. Hence, research was undertaken to resolve the true taxonomic position of this haemogregarine. Blood smears from nine wild tortoises of two species, Stigmochelys pardalis and Kinixys zombensis, from South Africa were screened, with the focus on H. parvula. Parasite DNA was extracted from ethanol-preserved blood samples, and fragments of the 18S rDNA gene were amplified by PCR using the primer sets HepF300/HepR900 and 4558/2733. Maximum likelihood and maximum parsimony analyses of 18S rDNA sequences showed that Haemogregarina parvula formed a monophyletic clade with species of Hemolivia within the Hepatozoon clade, not with species of Haemogregarina. It is thus recommended that this haemogregarine be reassigned to the genus Hemolivia, rendering Hemolivia parvula (Dias, 1953) the first species of the genus recorded from southern African tortoises.

Haemogregarines of freshwater turtles from Southeast Asia with a description of Haemogregarina sacaliae sp. n. and a redescription of Haemogregarina pellegrini Laveran and Pettit, 1910.

The uniform morphology of the developmental stages of Haemogregarina species and the insufficient information supplied by the simplistic descriptions of previous authors complicates their differential diagnosis and proper species identification. In this study, we detected Haemogregarina spp. in 6 out of 22 (27.2%) examined turtles originating from Southeast Asia, Malayemys subtrijuga (n = 4), Sacalia quadriocellata (n = 1) and Platysternon megacephalum (n = 1), and compared them with the available literature data. Microscopic analysis of our isolates distinguished 2 morphological species, Haemogregarina pellegrini and one new species, being described in this paper as Haemogregarina sacaliae sp. n. Phylogenetic analyses based on 1210 bp long fragment of 18S rDNA sequences placed both haemogregarines firmly within the monophyletic Haemogregarina clade. Isolates of H. pellegrini from 2 distantly related turtle hosts, M. subtrijuga and P. megacephalum, were genetically identical. Despite the fact that numerous Haemogregarina species of turtles have been described, the incompleteness of the morphological data and relatively low host specificity provides the space for large synonymy within this taxon. Therefore, a complex approach combining microscopic analyses together with molecular-genetic methods should represent the basic standard for all taxonomic studies.

Life cycle of Hepatozoon affluomaloti sp. n. (Apicomplexa: Haemogregarinidae) in crag lizards (Sauria: Cordylidae) and in culicine mosquitoes from South Africa.

A new haemogregarine species Hepatozoon affluomaloti sp. n. is described from erythrocytes in the peripheral blood of crag lizards Pseudocordylus melanotus (Smith) and Pseudocordylus subviridis (Smith) (Sauria: Cordylidae) from mountainous regions in the Eastern Free State, South Africa. This species can be distinguished from all other congeners based on its large size, staining properties and life cycle development in its vector, Culex (Afroculex) lineata (Theobald) (Diptera: Culicidae). Mature gamonts stain mostly uniformly pinkish-purple with Giemsa, sometimes containing darker azurophilic granules anterior and posterior to the nucleus. The reflexed posterior extremity of the gamont stage sometimes stains slightly deeper purple and the nucleus is dense and placed in the posterior third of the parasite body. Merogonic stages of this haemogregarine occur in the liver tissues of P. melanotus with dizoic meronts. Macromeronts contains 2-7 macromerozoites and micromeronts contains 9-24 micromerozoites. Sporogonic developmental stages found in the proposed final host and vector, C. lineata, include large oocysts, measuring 54 × 48 µm on average. Sporulating oocysts with 8 nuclei are present in mosquitoes 6-7 days post-feeding on infected lizards. Sporocysts with mature sporozoites measure 31.0 × 21.8 µm on average and each contains 2-8 large sporozoites. It is suggested that transmission of infective sporozoites is achieved through predation of lizards on mosquitoes.

Redescription and molecular diagnosis of Hepatozoon theileri (Laveran, 1905) (Apicomplexa: Adeleorina: Hepatozoidae), infecting Amietia quecketti (Anura: Pyxicephalidae)

Blood smears prepared from the peripheral blood of 20 wild caught Amietia quecketti (Boulenger) from the North-West University Botanical Gardens, North West Province, South Africa, were examined for the presence of haemogregarines. A haemogregarine species comparative in morphology, host and geographical locality to that of Haemogregarina theileri Laveran, 1905 was detected. The original description of H. theileri was based solely on frog peripheral blood gamont stages. Later, further parasite stages, including trophozoites and merogonic liver stages, were recorded in a related Amietia sp. from equatorial Africa. This species was originally classified as a member of the genus Haemogregarina Danilewsky, 1885, but due to the close life cycle and morphological resemblance to those of Hepatozoon species, H. theileri was later transferred from Haemogregarina to Hepatozoon Miller, 1908. In the present study, meront and merozoite stages not described before, along with previously observed trophozoite, immature and mature gamont stages, are described from the peripheral blood of hosts. In addition, comparative phylogenetic analysis of the partial 18S rDNA sequence of Hepatozoon theileri to those of other haemogregarine species, including those of species of Hepatozoon and a Haemogregarina, support the taxonomic transfer of H. theileri to Hepatozoon, nesting H. theileri within a clade comprising species parasitising other amphibians. This is the first molecular and phylogenetic analysis of an African anuran species of Hepatozoon.

A description of Haemogregarina species naturally infecting white-spotted gecko (Tarentola annularis) in Qena, Egypt.

The present study describes the developmental stages of Haemogregarina species in the blood and tissues of naturally infecting white-spotted gecko Tarentola annularis collected from Qena, Egypt. Different parasite's forms were observed infecting the erythrocytes. The gamonts enclosed within parasitophorous vacuole and seems to have no clear effect on the host cell especially in case of immature parasite forms. But in the presence of mature gamonts the host cell nucleus displaced. The parasitaemia level is up to 280 per 10,000 erythrocytes counted. Trophozoites and gamonts have been recognized in the blood smears. The rounded trophozoite diameter is 3.84 ±0.87 μm, while the elongated trophozoite measured 4.42 ± 0.69 x 2.8 ± 0.56 μm. The mature gamonts were differentiated into two forms; short gamont measuring 10.82 ± 0.82 x 3.30 ± 0.73 μm (range: 10-12.1 x 2.2-4.4 μm) and the long gamont measured 14.67 ± 0.83 x 3.96 ± 0.77 μm (range: 14.1-16.5 x 3.3-5.5 μm). Merogony carried out only in the endothelial cells of the blood capillaries in the lung. Different merogonic stages have been recognized and differentiated in two forms; micromeront measured 13.25 ± 0.50 x 12 ± 0.0 μm and produces a few number of large merozoites, macromeront measured 19.75+0.87x13.25+0.50 im and produces more small sized merozoites. The gamonts and merozoites have the general characteristic ultrastructures of the Apicomplexa containing components of the apical complex, e.g. pellicle, micronemes, rhoptries, and few dense bodies and subpellicular microtubules.