Two New Eimerians from American Alligator, Alligator mississippiensis (Crocodilia: Alligatoridae), from Georgia, USA.

PURPOSE: Little is known about the coccidian parasites of the American alligator, Alligator mississippiensis (Daudin). To date, only two species of Eimeria Schneider, 1875 have been previously reported from A. mississippiensis. Here, we report from mensural and morphometric data on two new species of Eimeria from A. mississippiensis from Georgia, USA. METHODS: Fresh feces were collected in June 2023 from a single captive juvenile male A. mississippiensis. Multiple samples were placed in individual zip-lock bags and aqueous potassium dichromate was added. They were examined for sporulated oocysts after flotation in Sheather's sugar solution, measured, and photographed. RESULTS: Samples contained oocysts representing two new species of Eimeria. Oocysts of Eimeria tellezae n. sp. are subspheroidal to ellipsoidal with a pitted bi-layered wall, measure (L × W) 34.5 × 31.5 µm, and have a length/width (L/W) ratio of 1.1; a micropyle and polar granule were absent but an oöcyst residuum was present. Sporocysts are ellipsoidal and measure 17.2 × 7.7 µm, L/W 2.2; a nipple-like Stieda body bearing one to several filaments was present but sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum is composed of various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. Oocysts of Eimeria daudini n. sp. are ellipsoidal with a pitted bi-layered wall, measure (L × W) 32.5 × 20.2 µm, and have a length/width (L/W) ratio of 1.6; a micropyle and polar granule were absent but an oöcyst residuum was present. Sporocysts are ellipsoidal and measure 15.4 × 7.4 µm, L/W 2.1; a nipple-like Stieda body bearing one to several filaments was present but sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum is composed of various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. Both new species can readily be distinguished from previously described eimerians from crocodilians, including those from A. mississippiensis. CONCLUSION: We document two new species of Eimeria from the American alligator. Currently, four species of Eimeria are known from A. mississippiensis examined from both east and west of the Mississippi River, USA.

The first report of Cryptosporidium testudinis in Chinese alligators (Alligator sinensis) in China.

Several Cryptosporidium species that infect reptiles, especially squamates, are well described, but there is limited data about Cryptosporidium species infecting crocodilians. In this study, we assess the occurrence of intestinal parasites using traditional microscopic examination and describe the prevalence and Cryptosporidium species in the captive-bred Chinese alligators (Alligator sinensis) in eastern China using molecular methods. The results of microscopic examination showed that no intestinal parasites were detected among the 491 fecal samples examined from the Chinese alligators. The overall prevalence for Cryptosporidium was 0.41% (2/491) by PCR detection using the SSU rRNA locus. Sequence and phylogenetic analysis of the SSU rRNA, COWP, and actin genes revealed the presence of Cryptosporidium testudinis, which has been isolated primarily from chelonians. This is the first detection of the specific DNA of C. testudinis in the feces of the Chinese alligator. This study expands our knowledge of the Cryptosporidium species involved in crocodiles, and more extensive studies are necessary to confirm the validity of C. testudinis in crocodiles.

The Coccidia (Apicomplexa) of the Archosauria (Crocodylia: Eusuchia) of the World.

The order Crocodylia (suborder Eusuchia) includes 27 species of alligators, caimans, crocodiles, and gharials that are cosmopolitan in distribution, inhabiting subtropical and tropical locations. Numerous surveys (many of them trivial, with small sample sizes) have reported a wide variety of blood and intestinal apicomplexans from 17/27 (63%) crocodilian hosts, but neither a summation for the group nor a revisionary systematic approach to species evaluation has ever been provided. Herein, we summarize information on the 16 species of apicomplexans that we consider to be valid, including 8 Eimeria, 1 Haemogregarina (that eventually may be transferred to Hepatozoon), 4 Hepatozoon, 2 Isospora, and 1 Progarnia species. In addition, there are 46 apicomplexan forms that we have relegated to species inquirendae and/or only partially identified forms that await further study. We hope this review provides a foundation for future research between parasitologists and herpetologists on parasitism of all reptiles and their relatives. Since many apicomplexans seem to be reasonably host-specific, knowledge of shared species and/or genera may assist herpetologists to better understand the phylogenetic relationships among the New World crocodilians and the direction of their dispersal in the New World.

Pathology associated with Odhneriotrema incommodum infection in wild-caught American alligators Alligator mississippiensis and assessment of potential first intermediate snail hosts.

AIMS: To assess pathological changes associated with natural infections of the trematode Odhneriotrema incommodum in wild-caught American alligators Alligator mississippiensis and assess potential first intermediate hosts. MATERIALS AND METHODS: Tongues from two wild-caught alligators were obtained from a commercial alligator processor in Port Gibson, Mississippi, USA. Tongues were subjected to gross parasitological examination and routine histological assessment. Eggs were expressed from adult trematodes collected from these tongues into distilled water, where they hatched into infectious miracidia. The snails Planorbella trivolvis, Physa gyrina, and Biomphalaria havanensis were exposed to these miracidia and observed for cercarial emergence for 200 days post-exposure. RESULTS: Histological assessment of alligator tongues revealed marked hemorrhage, necrosis, presence of bacteria, and inflammation at sites of Odhneriotrema incommodum attachment, differing from previous histological reports from controlled experimental studies. Cercarial emergence was not observed in snails exposed to infectious miracidia. CONCLUSIONS: Wild-caught alligators infected with Odhneriotrema incommodum exhibit more severe pathology than was previously noted from experimentally infected alligators. This adverse pathology may be associated with microbes present in eutrophic natural habitats that are absent from controlled environments used in experimental exposures. Impacts of this parasite in wild alligator populations are likely underestimated and damage associated with parasite attachment could increase host susceptibility to secondary infections. Given the importance of alligators as game animals and sustained demand for alligator products, further study into the role of O. incommodum on alligator health is warranted. Results of snail exposures to miracidia suggest these snail species are not suitable first intermediate hosts for this trematode and the true first intermediate host of O. incommodum remains unknown.

Tick infestation on caimans: a casual tick-host association in the Atlantic rainforest biome?

Ticks are parasites of birds, mammals, amphibians, and reptiles, but information about tick communities that parasitize reptiles in the Neotropical region is still fragmentary. In the present study, we assessed the presence of ticks on broad-snouted caimans (Caiman latirostris) and Cuvier's dwarf caimans (Paleosuchus palpebrosus) trapped in the Atlantic rainforest biome in Pernambuco state, north-eastern Brazil, to determine which tick species feed on these animals and how frequent or rare this parasite-wildlife association is. We also report an occasional finding of Amblyomma rotundatum on a smooth-fronted caiman (Paleosuchus trigonatus) in the Amazon biome in Pará state, northern Brazil. Out of 490 animals trapped in the Atlantic rainforest biome, four (0.82%) broad-snouted caimans were infested by ticks. Ticks belonged to two Amblyomma species: A. rotundatum (three females) and A. fuscum (one male). Our findings indicate that ticks are infrequent parasites of caimans in the Atlantic rainforest biome. Tick infestation on broad-snouted caimans is probably of minor clinical significance and probably a casual finding due to habitat sharing with the common tick hosts.

Phylogenetics, patterns of genetic variation and population dynamics of Trypanosoma terrestris support both coevolution and ecological host-fitting as processes driving trypanosome evolution.

BACKGROUND: A considerable amount of evidence has favored ecological host-fitting, rather than coevolution, as the main mechanism responsible for trypanosome divergence. Nevertheless, beyond the study of human pathogenic trypanosomes, the genetic basis of host specificity among trypanosomes isolated from forest-inhabiting hosts remains largely unknown. METHODS: To test possible scenarios on ecological host-fitting and coevolution, we combined a host capture recapture strategy with parasite genetic data and studied the genetic variation, population dynamics and phylogenetic relationships of Trypanosoma terrestris, a recently described trypanosome species isolated from lowland tapirs in the Brazilian Pantanal and Atlantic Forest biomes. RESULTS: We made inferences of T. terrestris population structure at three possible sources of genetic variation: geography, tapir hosts and 'putative' vectors. We found evidence of a bottleneck affecting the contemporary patterns of parasite genetic structure, resulting in little genetic diversity and no evidence of genetic structure among hosts or biomes. Despite this, a strongly divergent haplotype was recorded at a microgeographical scale in the landscape of Nhecolândia in the Pantanal. However, although tapirs are promoting the dispersion of the parasites through the landscape, neither geographical barriers nor tapir hosts were involved in the isolation of this haplotype. Taken together, these findings suggest that either host-switching promoted by putative vectors or declining tapir population densities are influencing the current parasite population dynamics and genetic structure. Similarly, phylogenetic analyses revealed that T. terrestris is strongly linked to the evolutionary history of its perissodactyl hosts, suggesting a coevolving scenario between Perissodactyla and their trypanosomes. Additionally, T. terrestris and T. grayi are closely related, further indicating that host-switching is a common feature promoting trypanosome evolution. CONCLUSIONS: This study provides two lines of evidence, both micro- and macroevolutionary, suggesting that both host-switching by ecological fitting and coevolution are two important and non-mutually-exclusive processes driving the evolution of trypanosomes. In line with other parasite systems, our results support that even in the face of host specialization and coevolution, host-switching may be common and is an important determinant of parasite diversification.

Two new species of ascaridoid nematodes in Brazilian Crocodylomorpha from the Upper Cretaceous.

Two new ascaridoid species, Bauruascaris cretacicus n. gen. et n. sp., and Bauruascaris adamantinensis n. gen. et n. sp., are described based on the fossils of eggs preserved in 80-70 million year old phosphatized coprolites of Crocodyliformes, chronologically assigned to the Upper Cretaceous (Campanian/Maastrichtian age), collected from sedimentary rocks of the Bauru Group, Adamantina Formation in the municipality of Santo Anastácio, in the southwestern region of the state of São Paulo, Brazil, South America. This paper describes the oldest ascaridoid species ever recorded in Crocodylomorpha. Hence, this article contributes to the body of knowledge about the evolutionary history of this nematode group. It also offers a clue about the composition of the parasite fauna of these reptiles from the Late Cretaceous, which is still unknown despite numerous studies about various aspects of their biology and the pioneering paleoparasitological analysis of animal coprolites by South American researchers.

The curious case of the endemic freshwater crocodile Crocodylus mindorensis as incidental host of marine fish acanthocephalan.

We performed the first host-parasite survey of the Philippine crocodile, Crocodylus mindorensis, a critically endangered species for which ecological information is lacking. We collected by gastric lavage samples of the stomach contents of crocodiles (n = 10) residing at the Palawan Wildlife Rescue and Conservation Center in Puerto Princesa, Palawan, Philippines. The only parasite detected was an acanthocephalan, which was identified as Neorhadinorhynchus nudus (n = 68), a parasite typically found in the marine fish species consumed by three crocodile individuals. Given the known hosts of N. nudus, its parasitism of C. mindorensis in captivity is likely established by consumption of marine fish. Our findings have implications for the conservation management of C. mindorensis, particularly in terms of preventing introduction of parasites that could lead to development of infectious disease or alter the fitness of captive animals.

Shared species of crocodilian trypanosomes carried by tabanid flies in Africa and South America, including the description of a new species from caimans, Trypanosoma kaiowa n. sp.

BACKGROUND: The genus Trypanosoma Gruby, 1843 is constituted by terrestrial and aquatic phylogenetic lineages both harboring understudied trypanosomes from reptiles including an increasing diversity of crocodilian trypanosomes. Trypanosoma clandestinus Teixeira & Camargo, 2016 of the aquatic lineage is transmitted by leeches to caimans. Trypanosoma grayi Novy, 1906 of the terrestrial lineage is transmitted by tsetse flies to crocodiles in Africa, but the vectors of Neotropical caiman trypanosomes nested in this lineage remain unknown. RESULTS: Our phylogenetic analyses uncovered crocodilian trypanosomes in tabanids from South America and Africa, and trypanosomes other than T. grayi in tsetse flies. All trypanosomes found in tabanids clustered in the crocodilian clade (terrestrial lineage) forming six clades: Grayi (African trypanosomes from crocodiles and tsetse flies); Ralphi (trypanosomes from caimans, African and Brazilian tabanids and tsetse flies); Terena (caimans); Cay03 (caimans and Brazilian tabanids); and two new clades, Tab01 (Brazilian tabanid and tsetse flies) and Kaiowa. The clade Kaiowa comprises Trypanosoma kaiowa n. sp. and trypanosomes from African and Brazilian tabanids, caimans, tsetse flies and the African dwarf crocodile. Trypanosoma kaiowa n. sp. heavily colonises tabanid guts and differs remarkably in morphology from other caiman trypanosomes. This species multiplied predominantly as promastigotes on log-phase cultures showing scarce epimastigotes and exhibited very long flagellates in old cultures. Analyses of growth behavior revealed that insect cells allow the intracellular development of Trypanosoma kaiowa n. sp. CONCLUSIONS: Prior to this description of Trypanosoma kaiowa n. sp., no crocodilian trypanosome parasitic in tabanid flies had been cultured, morphologically examined by light, scanning and transmission microscopy, and phylogenetically compared with other crocodilian trypanosomes. Additionally, trypanosomes thought to be restricted to caimans were identified in Brazilian and African tabanids, tsetse flies and the dwarf crocodile. Similar repertoires of trypanosomes found in South American caimans, African crocodiles and tabanids from both continents support the recent diversification of these transcontinental trypanosomes. Our findings are consistent with trypanosome host-switching likely mediated by tabanid flies between caimans and transoceanic migrant crocodiles co-inhabiting South American wetlands at the Miocene.

Nematodes found in Nile crocodiles in the Kruger National Park, South Africa, with redescriptions of Multicaecum agile (Wedl, 1861) (Heterocheilidae) and Camallanus kaapstaadi Southwell & Kirshner, 1937 (Camallanidae).

Sixteen Nile crocodiles were collected in the Kruger National Park, South Africa and vicinity during 2010 and 2011. A total of 11 nematode species representing six families were recovered. Heterocheilids were the dominant group, comprising five species, with Dujardinascaris madagascariensis (Chabaud & Caballero, 1966) being the most prevalent (75%), followed by Ingwenascaris sprenti Junker & Mutafchiev, 2017 (68.8%), which was also the second most numerous nematode. While less prevalent (31.3%), Typhlophoros kwenae Junker & Mutafchiev, 2017 was the most abundant species. Micropleura huchzermeyeri Junker & Mutafchiev, 2017 (Micropleuridae) was collected from five crocodiles and Crocodylocapillaria sp. (Capillariidae) occurred in a single host. Three nematodes, Camallanus kaapstaadi Southwell & Kirshner, 1937, Spirocamallanus sp. (both Camallanidae) and Ascarophis sp. (Cystidicolidae), are considered accidental infections, likely ingested with the hosts' prey. Our findings of D. dujardini (Travassos, 1920), D. madagascariensis and Multicaecum agile (Wedl, 1861) in South Africa constitute new geographical records. Crocodylocapillaria sp. represents a new host and geographical record, while T. kwenae, I. sprenti and M. huchzermeyeri have been described as new species during the course of this survey. Multicaecum agile is here redescribed based on light and scanning electron microscopy. Previously undescribed morphological characters of C. kaapstaadi, typically a parasite of Xenopus spp. (Amphibia: Pipidae), but here found in two Nile crocodiles, are also presented.

Morphological, Molecular, and Histopathological Data for Sebekia mississippiensis Overstreet, Self, and Vliet, 1985 (Pentastomida: Sebekidae) in the American Alligator, Alligator mississippiensis Daudin, and the Spotted Gar, Lepisosteus oculatus Winchell.

Novel molecular data from both mitochondrial ( cytochrome c oxidase subunit 1) and ribosomal regions ( 18S, ITS1-5.8S, ITS2, and 28S) are provided for Sebekia mississippiensis Overstreet, Self, & Vliet, 1985 , a pentastome infecting the American alligator, Alligator mississippiensis Daudin, 1801, and the spotted gar, Lepisosteus oculatus Winchell, 1864. Adult and nymphal pentastomes are described from the lungs and liver of the type host, A. mississippiensis, collected from Mississippi, while additional nymphs are described from the esophageal lining of L. oculatus specimens collected from Louisiana. This sequencing data will facilitate more accurate identification of various life cycle stages of S. mississippiensis, enabling future work to resolve many ambiguities in the literature regarding this species. Additionally, histopathological data are provided from both the definitive and intermediate hosts.

Dermatological conditions of farmed Crocodilians: A review of pathogenic agents and their proposed impact on skin quality.

The control of pathogens that target crocodilian skin is essential to the long-term success and sustainability of intensive farming operations worldwide. To understand the impact these pathogens may have on the skin, a brief overview of skin histology is given. A review of the known viral, bacterial, fungal and helminth taxa associated with skin conditions in commercially significant crocodilian species is presented. Best management practices are discussed, with an emphasis on addressing extrinsic factors that influence transmission and pathogenicity. It is argued that, in the past, reduced immune function arising from inadequate thermal regulation was the leading cause of skin disease in captive crocodilians. Consequently, innovations such as temperature control, coupled with the adoption of more stringent hygiene standards, have greatly reduced the prevalence of many infectious skin conditions in intensively farmed populations. However, despite improvements in animal husbandry and disease management, viral pathogens such as West Nile virus, herpesvirus and poxvirus continue to afflict crocodilians in modern captive production systems.

RETROSPECTIVE EVALUATION OF A NOVEL SUSTAINED-RELEASE IVERMECTIN VARNISH FOR TREATMENT OF WOUND MYIASIS IN ZOO-HOUSED ANIMALS.

Myiasis is a major disease condition in human and veterinary medicine. Domestic, free-ranging, and zoo-housed animals can be severely affected by myiasis. Depending on case severity, multiple treatment episodes may be indicated and can lead to recurrent capturing, handling stress, and anesthetics, all of which increase the risk of adverse responses (including death) individually and also in the herd. As an insecticide, ivermectin is often used for larval control. A total of 28 individual myiasis cases were retrospectively evaluated, out of which 11 cases were also treated using an ivermectin sustained-release varnish (SRV). The clinical outcome of all cases was assessed and the results suggest that the use of a topical ivermectin SRV (with or without concurrent injectable ivermectin) can reduce handling and treatments, has no adverse effects, and has minimal recurrence of the disease when compared with cases treated without it.

A New Interpretation of the Crocodile Forelimb Morphological Features as Adaptation to Parasagittal Quadrupedal Locomotion on the Ground.

We describe the crocodile forelimb features that distinguish them from other reptiles. Reduction of the clavicle and a change in the coracoid shape seem to be another way of maintaining the efficient step length, while the antebrachium and manus transformations create peculiar oblique manus position on the ground to promote the forelimb parasagittalization.

Characterization of the complete mitochondrial genome of Ortleppascaris sinensis (Nematoda: Heterocheilidae) and comparative mitogenomic analysis of eighteen Ascaridida nematodes.

Ortleppascaris sinensis (Nematoda: Ascaridida) is a dominant intestinal nematode of the captive Chinese alligator. However, the epidemiology, molecular ecology and population genetics of this parasite remain largely unexplored. In this study, the complete mitochondrial (mt) genome sequence of O. sinensis was first determined using a polymerase chain reaction (PCR)-based primer-walking strategy, and this is also the first sequencing of the complete mitochondrial genome of a member of the genus Ortleppascaris. The circular mitochondrial genome (13,828 bp) of O. sinensis contained 12 protein-coding, 22 transfer RNA and 2 ribosomal RNA genes, but lacked the ATP synthetase subunit 8 gene. Finally, phylogenetic analysis of mtDNAs indicated that the genus Ortleppascaris should be attributed to the family Heterocheilidae. It is necessary to sequence more mtNDAs of Ortleppascaris nematodes in the future to test and confirm our conclusion. The complete mitochondrial genome sequence of O. sinensis reported here should contribute to molecular diagnosis, epidemiological investigations and ecological studies of O. sinensis and other related Ascaridida nematodes.

Typhlophoros kwenae n. sp. (Nematoda: Ascaridida: Heterocheilidae), a gastric parasite from the Nile crocodile Crocodylus niloticus Laurenti (Reptilia: Crocodylidae) in South Africa.

Based on light and scanning electron microscopical observations, Typhlophoros kwenae n. sp. (Heterocheilidae), a new nematode parasite, is described from the stomach of the Nile crocodile Crocodylus niloticus Laurenti in South Africa. In having three lips with well-developed posterior prolongations and prominent interlabial longitudinal cuticular ridges, four pairs of precloacal papillae and complex spicules divided into handle and broad alate blade in males, as well as the position of the vulva near mid-body in females, the specimens conform to the generic diagnosis of Typhlophoros von Linstow, 1906. They can, however, be distinguished from the two previously described congeners, T. lamellaris von Linstow, 1906 and T. spratti Sprent, 1999, by the number of complete interlabial ridges, the length of spicules in males and the position of the vulva as well as the length of the tail in females. This is the first record of the genus Typhlophoros from the Afrotropical Realm.

Hepatozoon caimani in Caiman crocodilus yacare (Crocodylia, Alligatoridae) from North Pantanal, Brazil.

Hepatozoon species are the most common intracellular hemoparasite found in reptiles. Hepatozoon caimani, whose vectors are Culex mosquitoes, has been detected in a high prevalence among caimans in Brazil by blood smears examinations. The present work aimed to detect and characterize the Hepatozoon spp. found in 33 caimans (24 free-ranging and 9 captive; 28 males and 5 females) (Caiman crocodilus yacare) sampled at Poconé, North Pantanal, state of Mato Grosso, Brazil, using blood smears examinations and molecular techniques. Hepatozoon spp.-gametocytes were found in 70.8% (17/24) and 88.8% (8/9) of blood smears from free-ranging and captive caimans, respectively. Hepatozoon spp. 18S rRNA DNA was found in 79.2% (19/24) and 88.8% (8/9) of free-ranging and captive caimans, respectively. Comparative analysis of parasitized and non-parasitized erythrocytes showed that all analyzed features were significantly different (P<0.05) for both linear and area dimensions. Phylogenetic analysis based on 18S rRNA sequences grouped the Hepatozoon spp. sequences detected in the present study together with H. caimani, recently detected in caimans in southern Pantanal.

Alligator wrestling: morphological, molecular, and phylogenetic data on Odhneriotrema incommodum (Leidy, 1856) (Digenea: Clinostomidae) from Alligator mississippiensis Daudin, 1801 in Mississippi, USA.

Based on specimens collected from harvested American alligator Alligator mississippiensis Daudin, 1801 in Mississippi, USA, novel molecular data for both nuclear ribosomal genes (18S, ITS1-5.8S, ITS2, and 28S) and mitochondrial genes (cytochrome c oxidase subunit 1 and nicotinamide adenine dinucleotide dehydrogenase subunit 1) are provided for Odhneriotrema incommodum (Leidy, 1856), a trematode of the family Clinostomidae Lühe, 1901 infecting A. mississippiensis and the Florida spotted gar Lepisosteus platyrhincus DeKay, 1842. This represents the first sequencing data available for the genus Odhneriotrema and the subfamily Nephrocephalinae Travassos, 1928. Additionally, the results of phylogenetic analyses, additional morphometric data, a photomicrograph, and a line drawing supporting the present identification of O. incommodum are provided. These data will aid in elucidating the life cycle of O. incommodum through molecular identification of larval stages as well as understanding the evolutionary history of Clinostomidae and its subfamilies. Implications for the currently accepted organization of the Clinostomidae are discussed.

Ingwenascaris n. g. (Nematoda: Ascaridida: Heterocheilidae) established for I. sprenti n. sp. and I. assymmetrica (Ortlepp, 1932) n. comb., parasites of African crocodiles, and an identification key to the genera of the Heterocheilidae.

Ingwenascaris n. g. (Nematoda: Heterocheilidae) is established to accommodate Ingwenascaris sprenti n. g., n. sp., described from the stomach of Crocodylus niloticus Laurenti (Reptilia: Crocodylidae) in South Africa, based on light and scanning electron microscopy studies of its morphology. The new genus can be distinguished from other heterocheilid genera through a combination of its characters, including the pronounced asymmetry of each subventral lip due to an alate ventral margin and a non-alate margin facing the dorsal lip, the presence of continuous ridges of triangular denticles along the free labial margins, the lack of interlocking processes or a rostral plate, interlabia being indistinct or represented by small lateral interlabia between the dorsal and ventral lips only, the absence of prominent interlabial longitudinal cuticular ridges, the presence of lateral alae that are fused with the subventral lips, the presence of lateral caudal alae in both sexes, spicules of males that are composed of handle and alate blade, the presence of a gubernaculum, the number and arrangement of male caudal papillae and the position of the vulva near the anterior and middle third of the body in females. Ingwenascaris sprenti n. g., n. sp. represents the sixth heterocheilid genus parasitising African crocodilians. Trispiculascaris assymmetrica (Ortlepp, 1932) (syn. Porrocaecum assymmetricum Ortlepp, 1932) from a Central African crocodile is transferred to the new genus as I. assymmetrica (Ortlepp, 1932) n. comb. The genus Trispiculascaris Skrjabin, 1916 is considered a genus incertae sedis. An identification key to the genera of the family Heterocheilidae is presented.

Hepatozoon caimani in Caiman crocodilus yacare (Crocodylia, Alligatoridae) from North Pantanal, Brazil / Hepatozoon caimani em Caiman crocodilus yacare (Crocodylia, Alligatoridae) do Norte do Pantanal, Brasil

Abstract Hepatozoon species are the most common intracellular hemoparasite found in reptiles. Hepatozoon caimani, whose vectors are Culex mosquitoes, has been detected in a high prevalence among caimans in Brazil by blood smears examinations. The present work aimed to detect and characterize the Hepatozoon spp. found in 33 caimans (24 free-ranging and 9 captive; 28 males and 5 females) (Caiman crocodilus yacare) sampled at Poconé, North Pantanal, state of Mato Grosso, Brazil, using blood smears examinations and molecular techniques. Hepatozoon spp.-gametocytes were found in 70.8% (17/24) and 88.8% (8/9) of blood smears from free-ranging and captive caimans, respectively. Hepatozoon spp. 18S rRNA DNA was found in 79.2% (19/24) and 88.8% (8/9) of free-ranging and captive caimans, respectively. Comparative analysis of parasitized and non-parasitized erythrocytes showed that all analyzed features were significantly different (P<0.05) for both linear and area dimensions. Phylogenetic analysis based on 18S rRNA sequences grouped the Hepatozoon spp. sequences detected in the present study together with H. caimani, recently detected in caimans in southern Pantanal.

Resumo Espécies do gênero Hepatozoon são os hemoparasitas intracelulares mais comumente encontrados em répteis. Hepatozoon caimani, cujos vetores são mosquitos do gênero Culex sp., têm sido detectados em uma alta prevalência entre jacarés no Brasil, por meio da análise de esfregaços sanguíneos. O presente estudo objetivou detectar e caracterizar parasitas do gênero Hepatozoon spp. em 33 jacarés (24 de vida-livre e 9 de cativeiro; 28 machos e 5 fêmeas) (Caiman crocodilus yacare) amostrados em Poconé, região norte do Pantanal, estado do Mato Grosso, Brasil, por meio da análise de esfregaços sanguíneos e técnicas moleculares. Gametócitos de Hepatozoon spp. foram encontrados em 70,8% (17/24) e em 88,8% (8/9) dos esfregaços sanguíneos de jacarés de via-livre e cativeiro, respectivamente. 18S rRNA DNA de Hepatozoon spp. foi detectado em 79,2% (19/24) e 88,8% (8/9) das amostras de sangue de jacarés de vida-livre e cativeiro, respectivamente. A análise comparativa de eritrócitos parasitados e não parasitados mostrou diferença significativa (P<0,05) em todas as variáveis lineares e de área analisadas. A análise filogenética baseada em sequências de DNA do 18S rRNA agrupou as sequências de Hepatozoon spp. detectadas no presente estudo juntamente com aquelas de H. caimani, recentemente detectadas em jacarés do Pantanal do Mato Grosso do Sul.