Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

Unoculubranchiobdella sp. (Hirudinea: Ozobranchidae) as a vector for Haemogregarina spp. in freshwater turtles from Brazil

Species of Haemogregarina are blood parasites known to parasitise vertebrate hosts, including fishes (Haemogregarina sensu lato) and freshwater turtles (Haemogregarina sensu stricto). Their vectors, include gnathiid isopods and leeches, respectively. In turtles, Haemogregarina balli has the best-characterized life cycle in the genus. However, no studies in Brazil have suggested a possible vector for any species of Haemogregarina from freshwater turtles. Therefore, in the present study, we provide insights into a leech vector based on specimens found feeding on two species of freshwater turtles, Podocnemis unifilis and Podocnemis expansa, using morphological and molecular data. In 2017 and 2019, freshwater turtles were collected in Goiás State, Brazil. Hosts were inspected for ectoparasites and leeches were collected from two specimens of P. expansa and nine specimens of P. unifilis. Leeches were subsequently identified as members of the genus Unoculubranchiobdella. Leech histological slides revealed haemogregarine-like structures, similar to post-sporogonic merogony, found near the gills and within the posterior sucker. Molecular analysis of the haemeogregarines resulted in the identification of three species of Haemogregarina: Haemogregarina embaubali, Haemogregarina goianensis, and Haemogregarina brasiliana. Therefore, our findings, based on morphology and DNA data suggest leeches of the genus Unoculubranchiondella as vectors for at least three species of Haemogregarina from Brazilian turtles.

Hemoparasites Do Not Affect Life-History Traits and Cellular Immune Response in Treefrog Hosts Boana cordobae

We provide the first evidence for hemoparasites in the endemic Cordoba treefrog Boana cordobae. We collected 37 adult frogs at 1200 m a.s.l. in the Comechingones Mountains in the Córdoba province (Argentina). Each individual was sexed, then snout-vent length and body mass were recorded, a toe was collected for skeletochronological age determination, and a slide with a blood smear was prepared for hemoparasite screening, before releasing the frogs in situ. A total of 81% (n = 30) of the frogs were infected by hemogregarines and trypanosomes with a high intensity of infections. Dactylosoma was found for the first time in Argentina. Hemoparasites had no significant effect on the leukocyte profile, which we assessed from the May-Grünwald-Giemsa-stained blood smears. The neutrophils/lymphocytes ratio, indicative of stress, was insignificantly higher (0.06) in parasitized frogs than in parasite-free individuals (0.04). Infected frogs were larger than the controls, but this effect vanished when correcting size data for age. Young frogs (first-breeders) dominated the age distribution of parasite-free individuals, suggesting that infection of frogs takes usually place after sexual maturation. Vectors transmitting hemoparasites to B. cordobae remain to be identified. We demonstrate that moderate to high intensities of hemoparasites do not significantly affect the cellular immune response of B. cordobae, or any of the life-history traits studied, nor did they show any external sign of disease.

Hematologic parameters and the effect of hemoparasites of wild anurans in Northern Sinaloa, Mexico

BACKGROUND

Few hematologic profiles for free-ranging amphibians are available. Hematologic evaluation is a useful tool for determining the health of amphibian populations and providing further knowledge for conservation actions.

OBJECTIVES

Hematologic variables and the presence and effect of hemoparasites in anuran species were evaluated in Northern Sinaloa, Mexico.

METHODS

Blood samples were collected from wild anurans of eight species to perform blood cell counts, leukocyte differential counts, and serum protein concentrations using manual methods and refractometry. In addition, morphologic identification and quantification of the hemoparasites were performed on blood smears.

RESULTS

Differences were observed by sex, age, and season for the hematologic values of Incilius alvarius (n = 23), Incilius mazatlanensis (n = 46), Rhinella horribilis (n = 64), Leptodactylus melanonotus (n = 46), Lithobates forreri (n = 135), Lithobates catesbeianus (n = 20), Smilisca fodiens (n = 42), and Scaphiopus couchii (n = 7). Intra- and extra-erythrocytic hemoparasites were found in 56.2% of amphibian hosts; the hemoparasite infection of R. horribilis and L. melanonotus was higher in the dry season, showing increases in erythroplastids and monocytes. For L. forreri, males were more infected than females, and increases in leukocytes were associated with infections of different types of hemoparasites species.

CONCLUSIONS

Hematologic values, hemoparasite prevalence, and the response to hemoparasite infection vary among amphibian species, sex, and age, as well as on season and hemoparasite type. This highlights the importance of hematologic evaluations in wild amphibian populations to determine the subclinical effects of hemoparasite infections.

Molecular characterization of haemosporidian and haemogregarine diversity in southwestern Iberian amphibians and reptiles

The knowledge of the diversity and geographic distribution of parasite species is the first step towards understanding processes of global epidemiology and species conservation. Despite recent increases in research on haemosporidian and haemogregarine parasites of reptiles and amphibians, we still know little about their diversity and parasite-host interactions, especially in the Iberian Peninsula, where a few studies have been conducted. In this study, the haemosporidian and haemogregarine diversity and phylogenetic relationships of the parasites in southwestern Iberian amphibians and reptiles were assessed using PCR approaches on blood samples of 145 individuals from five amphibian and 13 reptile species. The amphibians did not present any of both groups of parasites studied. Regarding reptiles, five Hepatozoon, one Haemogregarina, and one Haemocystidum haplotypes were found infecting four different species, revealing new host records for these parasites. Among them, we found one new Haemocystidium haplotype and three new and a previously reported Hepatozoon haplotype from a north African snake. The latter finding suggests that some Hepatozoon parasites may not be host-specific and have large geographic ranges even crossing geographical barriers. These results increased the knowledge about the geographic distribution and the number of known host species of some reptile apicomplexan parasites, highlighting the great unexplored diversity of them in this region.

Hematologic variables of free-living Leptodactylus luctator with and without hemoparasites and thrombidiform mites in southern Brazil

It has been suggested that anuran amphibian parasites can cause clinical signs in situations of environmental imbalance. In the family Leptodactylidae, information about hematology is scarce, although these are well-known tools for the diagnosis and prognosis in clinical practice and potential bioindicators of environmental stress. The objective of this study is to describe Leptodactylus luctator hematology, to report the occurrence of hemoparasites and thrombidiform mites, and to compare the hematological variables under the presence and absence of these organisms. Ectoparasites and heparinized blood samples from 40 free-living specimens of L. luctator were collected for analysis. Hematologic variables and total plasma protein were compared between groups with and without hemoparasites and intradermal mites. As results, structures compatible with hemogregarines, Lankesterella sp., five morphotypes of Trypanosoma spp., microfilaria, Aegyptianella sp., an unidentified intraleukocytic hemoparasite, and frog erythrocytic virus (FEV) inclusion bodies were identified in the blood samples, besides Hannemania spp. intradermal mites. The hemoparasite occurrence was higher than previously reported in other anuran families and locations. Also, L. luctator has smaller red blood cells (RBCs) and white blood cells (WBCs), and a hyposegmentation of the neutrophil nucleus, when compared to many other amphibians. White blood cell, neutrophil, and monocyte counts were higher in animals parasitized by mites. There was no correlation between the number of parasitized RBCs and hematologic variables. This study provides anuran hematologic information, in addition to indicating a host reaction to infestation by Hannemania spp. mites, besides constituting the first record of the distribution of hemoparasites and intradermal mites in L. luctator of the study region.

Diversity of Haemogregarine Parasites Infecting Brazilian Anurans, with a Description of New Species of Dactylosoma (Apicomplexa: Adeleorina: Dactylosomatidae)

PURPOSE

Brazilian anurans are considered the most diverse and species rich around the world. Although in recent years there has been a strong focus on research related to this group of animals, their parasites have not received the same attention. Thus, this study aimed to provide morphological and molecular data on haemogregarines biodiversity infecting Brazilian anurans.

METHODS

During 2020, 116 anurans were collected from four Brazilian States and their blood and fragment of organs were screened for haemogregarine parasites.

RESULTS

From the total, seven (6.03%) animals were found infected with species of Hepatozoon and Dactylosoma. Based on the morphological and molecular analysis, four anurans were found infected with Hepatozoon latrensis. The phylogenetic analysis has shown the isolates from this study grouping with the Brazilian anuran Hepatozoon clade, also with gene similarity ranging from 99.70 to 100% to H. latrensis isolates available on GenBank. Furthermore, three specimens (Trachycephalus typhonius, Leptodactylus latrans, and Rhinella diptycha) were infected with the same species of Dactylosoma (100% genetic similarity), with a genetic similarity of 98.56% to Dactylosoma piperis the only other species described in Brazil. In support of the molecular data, different morphological characters were observed in the blood smears as compared to D. piperis, suggesting that the species of Dactylosoma from the present study infecting three different species of Brazilian anurans is an undescribed species.

CONCLUSION

Thus, this study increases the knowledge of Brazilian anuran blood parasites and demonstrates the importance of using integrative approaches for the diagnosis of haemoparasites.

Effects of the habitat on anuran blood parasites in the Eastern Brazilian Amazon

Biological interactions play an important role in regulating and maintaining natural populations. Like most interactions, parasitism may be influenced by environmental conditions. Therefore, changes caused by human activity may drastically affect the equilibrium of the assemblages of parasitized organisms (hosts). Herein, we described the composition of hemoparasites of anurans from two distinct environments: forest and oil palm plantations. We identified the most frequent groups of blood parasites, and whether infections differ between habitats (forest and plantation) and between microhabitats (arboreal or terrestrial). We collected 128 anurans, of which 46 (36%) were parasitized by hemoparasites. The genus Trypanosoma spp. was found in 30% (n = 37/128) of the infected anurans in both habitats, recorded mostly in terrestrial anurans in oil palm plantations. Apicomplexa hemoprotozoans were also found in 13% (n=17/128) of the anurans, which mainly were terrestrial species collected in oil palm plantations. There was no difference in parasitism between the two assemblies and between the studied microhabitats. This is the first study that has analyzed the ecological relationship between anurans as hosts and their blood parasites, in a region under intense anthropic pressure, in the Brazilian Amazon.

Regional Scale Risk to the Ecological Sustainability and Ecosystem Services of an African Floodplain System

The Phongolo floodplain is one of southern Africa's most important systems. In this study, we carried out a regional scale ecological risk assessment to evaluate the risk of multiple stressors associated with the use of the aquatic resources in the floodplain to selected social and ecological endpoints representing its sustainability. The floodplain has undergone significant changes as a result of the impacts of multiple stressors. This includes high risk of impact and threatened sustainability between the Pongolapoort Dam and the Ndumo Game Reserve (NGR). This compares to relatively low risk to the maintenance of the endpoints within the NGR. The reserve provides a protection and refuge function for regional biodiversity maintenance and ecosystem sustainability processes. In the study a range of scenarios were considered and demonstrate that the system will respond to protection measures and or increased resource use options. Should flood reductions or water quality pollution drivers continue on increasing trajectories, the condition of the Phongolo River and floodplain will probably deteriorate into an unacceptable, unsustainable state. Removal of the protection services of the NGR would result in an unsustainable ecosystem and loss of ecosystem services for regional vulnerable African communities. Additional evidence should be obtained from monitoring and research to refine, validate, and update the assessment in an adaptive management context. The risk assessment framework approach implemented in the Phongolo floodplain can contribute to the management of other floodplains ecosystems and the sustainability management of social and ecological attributes and processes of these important ecosystems.

Environmental, anthropogenic, and spatial factors affecting species composition and species associations in helminth communities of water frogs (Pelophylax esculentus complex) in Latvia

We investigated factors affecting species composition and patterns of species associations in parasite communities of water frogs (Pelophylax esculentus complex), applying the distance-based redundancy analysis for component communities (assemblages harboured by host populations) and Markov random fields modelling for infracommunities (assemblages harboured by individual hosts), respectively. We asked (a) What are the relative effects of variation in environmental, land use (i.e., anthropogenic), and spatial factors on the variation in the species composition of component communities (i.e., in a locality)? and (b) What is the dominant pattern of species associations in infracommunities (in a host individual), and how do these associations vary along environmental and/or anthropogenic gradients? In component communities, the greatest portion of variation in helminth species composition was explained by the combined effects of space, anthropogenic pressure, and NDVI, with the pure effect of the spatial predictor being much stronger than the effects of the remaining predictors. In infracommunities, the probability of occurrence of some, but not all, helminth species depended on the occurrence of another species, with the numbers of negative and positive co-occurrences being equal. The strength and/or sign of associations of some species pairs were spatially stable, whereas interactions between other species pairs varied along the gradient of the amount of green vegetation, from negative to positive and vice versa. We conclude that the processes in parasite infracommunities and component communities in frogs are intertwined, with both bottom-up and top-down effects acting at different hierarchical scales.

Vector-borne zoonotic blood parasites in wildlife from Ecuador: A report and systematic review

Background and Aim:

Ecuador is a hugely diverse country, but information on infectious diseases in local wild animals is scarce. The aim of this study was to screen the presence of blood parasites in free-ranging wild animals admitted to the Wildlife Hospital at Universidad San Francisco de Quito, from April 2012 to January 2019.

Materials and Methods:

We identified blood parasites by microscopic observation of blood smears from free-ranging wildlife species that attended the Wildlife Hospital of Universidad San Francisco de Quito (Ecuador) from April 2012 to January 2019.

Results:

The microscopic evaluations of animals as potential reservoirs for vector-borne zoonotic blood parasites revealed the presence of Anaplasma spp., Babesia spp., Ehrlichia spp., Hepatozoon spp., microfilaria, Mycoplasma spp., and Trypanosoma spp. in previously unreported wildlife species. In addition, we performed a systematic review to understand the current knowledge gaps in the context of these findings.

Conclusion:

Our data contribute to the knowledge of blood parasites in wildlife from Ecuador. Furthermore, the potential transmission of these parasites to humans and domestic animals, current anthropogenic environmental changes in the region, and the lack of information on this suggest the importance of our results and warrant further investigations on infectious diseases in animals and humans and their relationship with environmental health as key domains of the One Health concept.

Survey of Ticks and Tick-Borne Rickettsial and Protozoan Pathogens in Eswatini

Ticks are widespread parasites of vertebrates and major vectors of pathogens to humans, domestic animals, and wildlife. In southern Africa, numerous tick species transmit diseases of economic and health importance. This study aimed to describe the occurrence of ticks and tick-borne pathogens in multiple land-use types and the possible role of ticks in the transmission of pathogen species. Using molecular techniques, we screened 1716 ticks for infection by rickettsial bacteria and protozoans. To characterize pathogen identity, we sequenced multiple loci from positive samples and analyzed sequences within a phylogenetic framework. Across the seven tick species collected as nymphs or adults, we detected Rickettsia, Anaplasma, Ehrlichia, Babesia, Hepatozoon, and Theileira species. We found that some tick species and tick-borne pathogens differed according to land use. For example, we found a higher density of Haemaphysalis elliptica and higher prevalence of Rickettsia in H. elliptica collected from savanna grasses used for livestock grazing near human settlements than savanna grasses in conservation areas. These findings highlight the importance of comprehensive surveillance to achieve a full understanding of the diversity and ecology of the tick-borne pathogens that can infect humans, domestic animals, and wildlife.

Two new species of Neofoleyellides (Nematoda: Onchocercidae) parasitising anuran amphibians in South Africa

The genus Neofoleyellides was recently erected for a single species, Neofoleyellides boerewors from bufonid hosts in South Africa. In present study, we discovered two undescribed species of Neofoleyellides, namely N. steyni n. sp. and N. martini n. sp. parasitising frogs Amietia delalandii and Leptopelis natalensis, respectively. Both species differ from N. boerewors and between each other in shape and relative length of oesophagus, size of spicules, arrangement of genital papillae and morphology of caudal alae in males. Phylogenetic analysis based on concatenated fragments of the 18S ribosomal ribonucleic acid (18S rRNA) and the Cytochrome oxidase c subunit I (COI) genes confirmed both species as Neofoleyellides sister to Icosiellinae and Oswaldofilariinae.

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Two new species of Neofoleyellides described from frogs Amietia delalandii and Leptopelis natalensis.

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Morphological characters of N. boerewors, N. steyni n. sp. and N. martini n. sp. compared.

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Phylogenetic tree based on 18S rDNA and COI mtDNA sequences generated.

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Morphological and phylogenetic characteristics of three Neofoleyellides spp. discussed.

New insights on the diversity of Brazilian anuran blood parasites: With the description of three new species of Hepatozoon (Apicomplexa: Hepatozoidae) from Leptodactylidae anurans

The Amphibia are considered the most threatened vertebrate class globally, yet in Brazil they are also one of the more diverse and species rich groups. Although, in recent years there has been strong focus on amphibian related research, their parasites have not received the same attention. In Brazil, only a single species of Hepatozoon, namely H. leptodactyli (Lesage, 1908) Pessoa, 1970, has been described from anuran hosts. The present study aimed to describe three new species of Hepatozoon parasitising Leptodactylus labyrinthicus and Leptodactylus latrans from Mato Grosso State, Brazil. From 66 anurans screened for haemogregarines, four belonging to the Leptodactylidae were found positive for species of Hepatozoon. Based on the morphological analysis of peripheral blood gamonts and spleen and liver tissue meronts, three different morphotypes of Hepatozoon spp. were identified. Morphotype 1 (M1) and morphotype 2 (M2) in L. labyrinthicus and morphotype 3 (M3) in L. latrans. Molecular data based on partial 18S rDNA sequences revealed an interspecific divergence, between the species ranging from 0.43% to 1.16%. Phylogenetic analysis recovered isolates from the present study monophyletic with other isolates from Brazilian reptile and anuran hosts, sister to a clade comprising species isolated from African, North American and European reptile and anuran host species. Thus, using morphological and molecular analysis three new species infecting Brazilian Leptodactylidae anurans were identified and described. This study increases the knowledge of Brazilian anurans blood parasites and demonstrates the importance of using integrative approaches for diagnosis of hemoparasites.

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Diversity and phylogenetic relationship of haemogregarines from Brazilian anurans.

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Description of a three new species of Hepatozoon from Brazilian anurans.

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First report of species of Hepatozoon descriptions using both morphological and molecular approaches from Brazilian anurans.

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Merogonic data of Hepatozoon spp. infection on Brazilian anurans.

Molecular detection of Apicomplexan hemoparasites in anurans from Brazil

Amphibians are among the most threatened vertebrate groups in the world, and the main causes include climate change, habitat destruction, and emerging diseases. Herein, we investigated the occurrence and characterized molecularly Apicomplexa in anurans from southeastern Brazil. Forty individuals from seven anuran species were sampled in São Paulo state. In the molecular analyses, one Leptodactylus latrans and one Rhinella diptycha were positive in PCR assays for species of Hepatozoon. Two L. latrans were also positive for coccidian infections (Lankesterella sp. and an unidentified coccidian species). Phylogenetic analysis based on 18S rDNA clustered the sequences detected in anurans from the present study with Hepatozoon spp. detected in reptiles and other anurans from Brazil, albeit they were separate from Hepatozoon haplotypes detected in frogs from Africa and North America. Our study showed, for the first time, the molecular detection of Lankesterella sp. and another coccidian in L. latrans. Additionally, co-infection by different species of Hepatozoon haplotypes and an unidentified coccidian in anurans from Brazil was documented.

Molecular characterisation and morphological description of two new species of Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina: Hepatozoidae) infecting leukocytes of African leopards Panthera pardus pardus (L.)

Background

The African leopard Panthera pardus pardus (L.) is currently listed as a vulnerable species on the IUCN (International Union for the Conservation of Nature) red list of threatened species due to ongoing population declines. This implies that leopard-specific parasites are also vulnerable to extinction. Intracellular apicomplexan haemoparasites from the genus Hepatozoon Miller, 1908 have been widely reported from wild carnivores in Africa, including non-specific reports from leopards. This paper describes two new haemogregarines in captive and wild leopards from South Africa and provides a tabular summary of these species in relation to species of Hepatozoon reported from mammalian carnivores.

Methods

Blood was collected from nine captive and eight wild leopards at various localities throughout South Africa. Thin blood smears were Giemsa-stained and screened for intraleukocytic haemoparasites. Gamont stages were micrographed and morphometrically compared with existing literature pertaining to infections in felid hosts. Haemogregarine specific primer set 4558F and 2733R was used to target the 18S rRNA gene for molecular analysis. Resulting sequences were compared to each other and with other available representative mammalian carnivore Hepatozoon sequences from GenBank.

Results

Two species of Hepatozoon were found in captive and wild leopards. Of the 17 leopards screened, eight were infected with one or both morphologically and genetically distinct haemogregarines. When compared with other species of Hepatozoon reported from felids, the two species from this study were morphometrically and molecularly distinct. Species of Hepatozoon from this study were observed to exclusively parasitize a particular type of leukocyte, with Hepatozoon luiperdjie n. sp. infecting neutrophils and Hepatozoon ingwe n. sp. infecting lymphocytes. Phylogenetic analysis showed that these haemogregarines are genetically distinct, with Hepatozoon luiperdjie n. sp. and Hepatozoon ingwe n. sp. falling in well supported separate clades.

Conclusions

To our knowledge, this is the first morphometric and molecular description of Hepatozoon in captive and wild African leopards in South Africa. This study highlights the value of using both morphometric and molecular characteristics when describing species of Hepatozoon from felid hosts.

An overview of the Dactylosomatidae (Apicomplexa: Adeleorina: Dactylosomatidae), with the description of Dactylosoma kermiti n. sp. parasitising Ptychadena anchietae and Sclerophrys gutturalis from South Africa

Haemogregarine (Apicomplexa: Adeleorina) blood parasites are commonly reported from anuran hosts. Dactylosomatidae (Jakowska and Nigrelli, 1955) is a group of haemogregarines comprising Dactylosoma Labbé, 1894 and Babesiosoma Jakowska and Nigrelli, 1956. Currently Dactylosoma and Babesiosoma contain five recognised species each. In the current study, a total of 643 anurans, comprising 38 species, 20 genera, and 13 families were collected from South Africa (n = 618) and Belgium (n = 25), and their blood screened for the presence of dactylosomatid parasites. Three anuran species were found infected namely, Ptychadena anchietae (Bocage, 1868) and Sclerophrys gutturalis (Power, 1927) from South Africa, and Pelophylax lessonae (Camerano, 1882) from Belgium. Based on morphological characteristics, morphometrics and molecular results a new dactylosomatid, Dactylosoma kermiti n. sp. is described form Pty. anchietae and Scl. gutturalis. The species of Dactylosoma isolated from Pel. lessonae could not, based on morphological or molecular analysis, be identified to species level. Phylogenetic analysis shows species of Dactylosoma infecting anurans as a monophyletic group separate from the other haemogregarine groups. Additionally, the mosquitoes Uranotaenia (Pseudoficalbia) mashonaensis Theobald, 1901 and U. (Pfc.) montana Ingram and De Meillon, 1927 were observed feeding on Scl. gutturalis in situ and possible dividing stages of this new parasite were observed in the mosquitoes. This study is the first to describe a dactylosomatid parasite based on morphological and molecular data from Africa as well as observe potential stages in possible dipteran vectors.

Neofoleyellides boerewors n. gen. n. sp. (Nematoda: Onchocercidae) parasitising common toads and mosquito vectors: morphology, life history, experimental transmission and host-vector interaction in situ

Anuran filarial nematodes are restricted to two comparatively small subfamilies (Icosiellinae and Waltonellinae) of the filariae that currently comprise six genera and 41 recognised species. However, the life histories of only five anuran filarial nematodes, proposed as an ancestral group based on molecular phylogenetic studies, have been elucidated. Furthermore, data on the natural vectors (in situ) and parasite transmission is limited. In the current study we elucidate the life history of Neofoleyellides boerewors n. gen. n. sp. parasitising the guttural toad, Sclerophrys gutturalis and the mosquito vectors Uranotaenia (Pseudoficalbia) mashonaensis and Uranotaenia (Pseudoficalbia) montana. Additionally, we report on the unique host-seeking behaviour of the mosquito vectors which locate their toad hosts using their calls. The complex host-vector relationship and specialised host-seeking behaviour by these mosquitoes indicate biases towards host species and male toad infections.

Linking organochlorine exposure to biomarker response patterns in Anurans: a case study of Müller's clawed frog (Xenopus muelleri) from a tropical malaria vector control region

Organochlorine pesticides are highly persistent in aquatic ecosystems. Amphibians, specifically anurans, play an intricate part in the aquatic food web, and have very permeable skin which makes them prone to bioaccumulation of persistent pollutants. In this study the bioaccumulation of various legacy organochlorine pesticides (OCPs)-including dichlorodiphenyltrichloroethane (DDT), currently used for malaria vector control (MVC)-was assessed along with a set of biomarker responses in Müller's clawed frog Xenopus muelleri collected from the lower Phongolo River floodplain in South Africa. Possible relationships between bioaccumulation and biomarkers (of exposure, oxidative stress biomarkers, and cellular energy allocation) alongside their temporal changes were investigated. The OCP concentrations showed a significant increase over time for the duration of the study. The increase correlated negatively with rainfall from the region. DDT levels were well below expected effects levels with p,p-DDE being the main contributing metabolite. The results of this study indicate OCPs actively accumulate at sub-lethal levels in aquatic frogs from the study area, while showing possible relations towards some of the biochemical stress responses measured. Most notable were negative relationships indicated between p,p-DDE and acetylcholinesterase, malondialdehyde, and carbohydrates and protein energy availability. Levels of DDT were not found to be significantly higher than other legacy pesticides in the frog tissue, although evidence of newly introduced DDT in the frog tissue was found. Further investigation about sub-lethal effects of these pesticides on anurans is required to gain better insight into their full impact on animal livelihood.

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.

Ultrastructural Comparison of Hepatozoon ixoxo and Hepatozoon theileri (Adeleorina: Hepatozoidae), Parasitising South African Anurans

To date, only two haemogregarine parasite species have been described from South African anurans: Hepatozoon ixoxo, infecting toads of the genus Sclerophrys (syn. Amietophrynus); and Hepatozoon theileri, parasitising the common river frog, Amietia quecketti. Both species have been characterised using limited morphology, and molecular data from PCR amplified fragments of the 18S rRNA gene. However, no ultrastructural work has been performed thus far. The aim of this study was to add descriptive information on the two species by studying their ultrastructural morphology. Mature gamont stages, common in the peripheral blood of infected frogs, were examined by transmission electron microscopy. Results indicate that H. ixoxo and H. theileri share typical apicomplexan characteristics, but differ markedly in their external cellular structure. Hepatozoon ixoxo is an encapsulated parasite presenting a prominent cap at the truncate pole, and shows no visible modifications to the host cell membrane. In comparison, H. theileri does not present a capsule or cap, and produces marked morphological changes to its host cell. Scanning electron microscopy was performed to further examine the cytopathological effects of H. theileri, and results revealed small, knob-like protrusions on the erythrocyte surface, as well as notable distortion of the overall shape of the host cell.

A new lizard malaria parasite Plasmodium intabazwe n. sp. (Apicomplexa: Haemospororida: Plasmodiidae) in the Afromontane Pseudocordylus melanotus (Sauria: Cordylidae) with a review of African saurian malaria parasites

Background

Saurian malaria parasites are diverse apicomplexan blood parasites including the family Plasmodiidae Mesnil, 1903, and have been studied since the early 1900s. Currently, at least 27 species of Plasmodium are recorded in African lizards, and to date only two species, Plasmodium zonuriae (Pienaar, 1962) and Plasmodium cordyli Telford, 1987, have been reported from the African endemic family Cordylidae. This paper presents a description of a new malaria parasite in a cordylid lizard and provides a phylogenetic hypothesis for saurian Plasmodium species from South Africa. Furthermore, it provides a tabular review of the Plasmodium species that to date have been formally described infecting species of African lizards.

Methods

Blood samples were collected from 77 specimens of Pseudocordylus melanotus (A. Smith, 1838) from Platberg reserve in the Eastern Free State, and two specimens of Cordylus vittifer (Reichenow, 1887) from the Roodewalshoek conservancy in Mpumalanga (South Africa). Blood smears were Giemsa-stained, screened for haematozoa, specifically saurian malaria parasites, parasite stages were photographed and measured. A small volume was also preserved for TEM studies. Plasmodium and Haemoproteus primer sets, with a nested-polymerase chain reaction (PCR) protocol, were employed to target a fragment of the cytochrome-b (cyt-b) gene region. Resulting sequences of the saurian Plasmodium species’ isolates were compared with each other and to other known Plasmodium spp. sequences in the GenBank database.

Results

The presence of P. zonuriae in both specimens of the type lizard host C. vittifer was confirmed using morphological characteristics, which subsequently allowed for the species’ molecular characterisation. Of the 77 P. melanotus, 44 were parasitised by a Plasmodium species, which when compared morphologically to other African saurian Plasmodium spp. and molecularly to P. zonuriae, supported its description as a new species Plasmodium intabazwe n. sp.

Conclusions

This is the first morphological and molecular account of Plasmodium species within the African endemic family Cordylidae from South Africa. The study highlights the need for molecular analysis of other cordylid Plasmodium species within Africa. Future studies should also include elucidating of the life-cycles of these species, thus promoting the use of both morphological and molecular characteristics in species descriptions of saurian malaria parasites.

Redescription, molecular characterisation and taxonomic re-evaluation of a unique African monitor lizard haemogregarine Karyolysus paradoxa (Dias, 1954) n. comb. (Karyolysidae)

BACKGROUND

Within the African monitor lizard family Varanidae, two haemogregarine genera have been reported. These comprise five species of Hepatozoon Miller, 1908 and a species of Haemogregarina Danilewsky, 1885. Even though other haemogregarine genera such as Hemolivia Petit, Landau, Baccam & Lainson, 1990 and Karyolysus Labbé, 1894 have been reported parasitising other lizard families, these have not been found infecting the Varanidae. The genus Karyolysus has to date been formally described and named only from lizards of the family Lacertidae and to the authors' knowledge, this includes only nine species. Molecular characterisation using fragments of the 18S gene has only recently been completed for but two of these species. To date, three Hepatozoon species are known from southern African varanids, one of these Hepatozoon paradoxa (Dias, 1954) shares morphological characteristics alike to species of the family Karyolysidae. Thus, this study aimed to morphologically redescribe and characterise H. paradoxa molecularly, so as to determine its taxonomic placement.

METHODS

Specimens of Varanus albigularis albigularis Daudin, 1802 (Rock monitor) and Varanus niloticus (Linnaeus in Hasselquist, 1762) (Nile monitor) were collected from the Ndumo Game Reserve, South Africa. Upon capture animals were examined for haematophagous arthropods. Blood was collected, thin blood smears prepared, stained with Giemsa, screened and micrographs of parasites captured. Haemogregarine morphometric data were compared with the data for named haemogregarines of African varanids. Primer set HepF300 and HepR900 was employed to target a fragment of the 18S rRNA gene and resulting sequences compared with other known haemogregarine sequences selected from the GenBank database.

RESULTS

Hepatozoon paradoxa was identified infecting two out of eight (25 %) V. a. albigularis and a single (100 %) V. niloticus examined. Phylogenetic analyses revealed that H. paradoxa clustered with the 'Karyolysus' clade, and not with those of reptilian Hepatozoon spp.

CONCLUSIONS

In addition to this being the first morphological and molecular characterisation of a haemogregarine within the African Varanidae, it is the first report of a species of Karyolysus infecting the monitor lizard family. Furthermore, this constitutes now only the third described and named Karyolysus species for which there is a nucleotide sequence available.