First report of a fish blood fluke from sub-Saharan Africa: Nomasanguinicola dentata (Paperna, 1964) Warren and Bullard, 2023 infecting African sharptooth catfish, Clarias gariepinus (Burchell, 1822) Teugles, 1982 in the Kavango River, Namibia, and a revised phylogeny for Sanguinicolidae Poche, 1926

We herein provide a supplemental description of Nomasanguinicola dentata (Paperna, 1964) Warren and Bullard, 2023 (Digenea: Sanguinicolidae) and provide a revised 28S phylogeny to test relationships among freshwater fish blood flukes. We examined the heart of three African sharptooth catfish, Clarias gariepinus (Burchell, 1822) Teugles, 1982 from the Kavango River (northeastern Namibia) that was infected with adults of N. dentata. This blood fluke differs from N. canthoensis by having a body 5.3-6.7 longer than wide (vs. 3.5-4.6), an anterior esophageal swelling 7-8% (vs. 14-24%) of total esophageal length, a posterior esophageal swelling 3-5% (vs. 8-10%) of total esophageal length, a pre-cecal (vs. wholly post-cecal) testis, and an ovary that does not extend laterally beyond the nerve cords. The 28S sequence for N. dentata differed from that of N. canthoensis by 144 bp (9% difference). The phylogenetic analysis recovered these species as sister taxa and Sanguinicolidae as monophyletic. This is the first report of a fish blood fluke from sub-Saharan Africa, and the first report of a species of Nomasanguinicola from Africa in ∼40 yrs.

DESCRIPTION OF FEMALE DENDRITOBILHARZIA PULVERULENTA (BRAUN, 1901) SKRJABIN, 1924 FROM TWO NEW AVIAN HOSTS IN NAMIBIA WITH PHYLOGENETIC ANALYSES AND COMMENTS ON SEVERAL TAXONOMICALLY UNCERTAIN AVIAN SCHISTOSOME SEQUENCES

During a 2021 parasitological survey of birds in the Nyae Nyae-Khaudum Dispersal Area (Kavango-Zambezi Transfrontier Conservation Area, Namibia), we collected 9 specimens of Dendritobilharzia pulverulenta (Braun, 1901) Skrjabin, 1924 infecting the blood (heart lumen) of a white-backed duck, Thalassornis leuconotus (Eyton, 1838) (Anseriformes: Anatidae), and a fulvous whistling duck, Dendrocygna bicolor (Vieillot, 1816) (Anatidae). These flukes were fixed for morphology and preserved for DNA extraction. We assigned our specimens to DendritobilharziaSkrjabin and Zakharow, 1920 because they were strongly dorso-ventrally flattened in both sexes and had an intestinal cyclocoel with a zig-zag common cecum with lateral dendritic ramifications, numerous testes posterior to the cyclocoel and flanking the dendritic ramifications, and a tightly compacted convoluted ovary as well as lacking an oral sucker, ventral sucker, and gynaecophoric canal. Further, our specimens were morphologically identical to previously published descriptions of D. pulverulenta. Sequences of the 28S from our specimens were nearly identical to those identified as D. pulverulenta from North America (New Mexico), and our 28S phylogenetic analysis recovered D. pulverulenta within a polytomy of other Gigantobilharziinae spp. The CO1 phylogenetic analysis recovered a monophyletic Dendritobilharzia and, with low taxon sampling, a monophyletic Gigantobilharzia. This is the first record of a species of Dendritobilharzia infecting these ducks as well as the first record of an adult Dendritobilharzia from sub-Saharan Africa. The original description of adult D. pulverulenta (type locality: northern Sudan) was based on 2 males only, and hence the present study is the first description of female D. pulverulenta from Africa (the continent of the type locality). We reassign 2 Gigantobilharziinae spp. based on morphology and nucleotide evidence: Gigantobilharzia ensenadense (Lorenti, Brant, Gilardoni, Diaz, and Cremonte, 2022) Dutton and Bullard, n. comb., and Gigantobilharzia patagonense (Lorenti, Brant, Gilardoni, Diaz, and Cremonte, 2022) Dutton and Bullard, n. comb. We also comment on several avian schistosome sequences whose identities need confirmation or that likely have been misidentified.

Barcoding and traditional health practitioner perspectives are informative to monitor and conserve frogs and reptiles traded for traditional medicine in urban South Africa

Previous literature suggests that Indigenous cultural practices, specifically traditional medicine, are commonplace among urban communities contrary to the general conception that such practices are restricted to rural societies. We reviewed previous literature for records of herptiles (frog and reptile species) sold by traditional health practitioners in urban South Africa, then used visual confirmation surveys, DNA barcoding and folk taxonomy to identify the herptile species that were on sale. Additionally, we interviewed 11 IsiZulu and SePedi speaking traditional health practitioners to document details of the collection and pricing of herptile specimens along with the practitioners' views of current conservation measures for traditional medicine markets. The 34 herptile species recorded in previous literature on traditional medicine markets included endangered and non-native species. Spectrophotometry measurements of the DNA we extracted from the tissue of herptiles used in traditional medicine were an unreliable predictor of whether those extractions would be suitable for further experimental work. From our initial set of 111 tissue samples, 81 sequencing reactions were successful and 55 of those sequences had species-level matches to COI reference sequences on the NCBI GenBank and/or BOLD databases. Molecular identification revealed that traditional health practitioners correctly labelled 77% of the samples that we successfully identified with DNA barcoding in this study. Our mixed methodology approach is useful for conservation planning as it updates knowledge of animal use in Indigenous remedies and can accurately identify species of high conservation priority. Furthermore, this study highlights the possibility of collaborative conservation planning with traditional health practitioners.

Morphological and molecular diagnosis of two new species of Trypanosoma Gruby, 1843 infecting South African cordylid lizards (Squamata: Cordylidae: Cordylinae), Trypanosoma (Squamatrypanum) ndumoensis n. sp. and Trypanosoma (Trypanosoma) tokoloshi n. sp

Despite reptile trypanosomes forming a large group, the majority of species descriptions are data deficient, lacking key characteristic data and supporting molecular data. Reptile hosts show potential to facilitate transmission of zoonotic trypanosomiases and offer key information to understanding the genus of Trypanosoma. Several species of squamates from different localities in South Africa were screened molecularly and microscopically for trypanosomes in the present study. Based on the combination of morphological and molecular analyses, two new species of Trypanosoma, Trypanosoma (Squamatrypanum) ndumoensis n. sp. and Trypanosoma (Trypanosoma) tokoloshi n. sp., infecting South African cordylid lizards (Cordylidae: Cordylinae) are described in this study. The first molecular data for a South African reptile trypanosome is provided herewith.

Diversity and distribution of benthic invertebrates dwelling rivers of the Kruger National Park, South Africa

Meiobenthos (or meiofauna) are microscopic invertebrates that inhabit biofilms and interstitial spaces in rivers. They are diverse and extremely abundant, and they perform essential ecological functions by linking microbial production to higher trophic levels (e.g. macrobenthic invertebrates and fishes). However, meiobenthic communities remain poorly studied in Africa. Here, we sampled meio- and macrobenthic invertebrate communities associated with biofilms and sediments across an upstream–downstream gradient along the Olifants, Sabie and Crocodile rivers flowing through the Kruger National Park (KNP). We expected to link differences in community structure to environmental gradients as those rivers show different degrees of anthropogenic stress as they enter the park. Both meio- and macrobenthic communities differed across rivers and also structured along an upstream–downstream gradient. The upstream sites, which were the closest to the park borders, consistently showed a lower diversity in all three rivers. There, the invasive snail Tarebia granifera strongly dominated (making up 73% – 87% of the macrobenthos), crowding hard substrates, while concomitantly the abundances of biofilm-dwelling meiobenthos like nematodes and rotifers were substantially reduced. Nevertheless, the diversity and evenness of communities then tended to increase as water flowed downstream through the park, suggesting a beneficial effect of protected river reaches on benthic invertebrate diversity. However, for the Crocodile River, which makes up the southern border of the park, this trend was less conspicuous, suggesting that this river may experience the greatest threats. More generally, benthic invertebrate communities were driven by the concentrations of phosphates, sulphates, ammonium and organic matter and by substrate characteristics.Conservation implications: Meiobenthic organisms are very abundant in KNP rivers and react to environmental gradients; thus, they should be more considered for bio-monitoring or conservation of comprehensive assemblages of animals. Interestingly, protected reaches tended to show a reduced dominance of the invasive T. granifera and a higher diversity of benthic invertebrates.

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.

Molecular confirmation of high prevalence of species of Hepatozoon infection in free-ranging African wild dogs (Lycaon pictus) in the Kruger National Park, South Africa

Reports in the literature indicate that species of Hepatozoon commonly occur in African wild dog (AWD) or painted wolf (Lycaon pictus) populations. These findings were based on examination of blood smears by microscopy, and specific identity of the Hepatozoon sp. gamonts seen could not be confirmed. We present the first in-depth molecular data on the prevalence of species of Hepatozoon in a free-ranging AWD population. In a general health survey of AWDs in the Kruger National Park, blood specimens (n = 74) collected from 54 individuals were examined for the presence of Hepatozoon spp. At first sampling, specimens from 42 of 54 individuals (77.7%) were positive, based on the primer set HepF300 and HepR900. Twenty individuals were resampled between 51 and 69 days after first sampling; one of these was resampled twice. Samples from six individuals that had tested negative previously now reacted positive. Assuming that all 54 individuals were still alive, the prevalence had therefore increased to 48 individuals infected, or 88.8%. Resultant 18S rDNA sequences isolated from these specimens share high similarity to other Hepatozoon canis genotypes. Phylogenetic analysis recovered the Hepatozoon sp. isolated from AWDs within the H. canis cluster, which includes species of Hepatozoon from other canid and tick hosts.

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First in-depth molecular data on the prevalence of species of Hepatozoon in a free-ranging African wild dog population.

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High prevalence (89%) of African wild dogs in the Kruger National Park parasitised with Hepatozoon sp.

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Two species of Hepatozoon genotypes sequenced from this African wild dog population.

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Resultant 18S rDNA sequences share a 99% similarity to Hepatozoon canis.

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.

A troglobitic species of the centipede Cryptops (Chilopoda, Scolopendromorpha) from northwestern Botswana

A new species of Cryptops, C. (Cryptops) legagussp. nov., occurs in caves in the Koanaka and Gcwihaba Hills in northwestern Botswana. Bayesian molecular phylogenetics using 18S rRNA, 28S rRNA, 16S rRNA and cytochrome c oxidase subunit I corroborates a morphological assignment to the subgenus Cryptops and closest affinities to southern temperate species in South Africa, Australia and New Zealand. The new species is not conspicuously modified as a troglomorph.

Polystoma luohetong n. sp. (Monogenea: Polystomatidae) from Rana chaochiaoensis Liu (Amphibia: Ranidae) in China

Polystoma chaochiaoensis from the urinary bladder of the chaochiao frog Rana chaochiaoensis Liu was briefly described in a symposium abstract and presented at the Third Symposium on Parasitology of China in 1990. Types were not assigned and the original specimens collected are no longer available. The morphological description was incomplete and no illustrations were provided. We consider Polystoma chaochiaoensis a nomen nudum and provide a full description for the species and assign types. Based on morphological characteristics and molecular data of partial 18S rDNA sequences, we describe this species as Polystoma luohetong n. sp. Out of 578 frogs examined, 16 male and 38 female frogs were infected (prevalence 9.3%; mean intensity 1.02). Polystoma luohetong n. sp. is distinguished from all other Polystoma species by the presense of a prominent crest on the hamulus as well as by the shape and size of marginal hooklets and the intestinal arrangement. Furthermore, the phylogentic analysis based on the 18S rRNA gene shows Polystoma luohetong n. sp. well nested within the Ploystoma clade and as a sister taxon to Polystoma integerrimum.

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.

Folk taxonomy and indigenous names for frogs in Zululand, South Africa

BACKGROUND

We use taxonomy to organize the world into recognizable units. Folk taxonomy deals with the naming and classification of organisms through culture. Unlike its scientific counterpart, folk taxonomy is mostly undocumented, the Zoological Code of Nomenclature does not regulate it, and the resulting names are specific to each culture. A growing body of literature is steadily shedding light on the principles underlying this pre-scientific taxonomy. Vernacular names can be an instrument to increase participation of non-scientists in biodiversity matters. In South Africa, great strides have been made in standardizing and increasing relatability of vernacular amphibian names in English and Afrikaans. However, there is a need to achieve the same with the country's autochthonous languages which are used by a majority of the population.

METHODS

This study investigates amphibian-related folk taxonomy using a semi-structured interview process in KwaZulu-Natal's Zululand region and  pilots methods of applying folk taxonomy principles to compile a comprehensive list of standardized indigenous frog names.

RESULTS

Folk taxonomy in Zululand is systematic, developed, and bears similarities to other indigenous taxonomies around the world. Similarities also exist between folk and scientific taxonomy. Six uninomial indigenous names were found to be used for the 58 amphibian species occurring in the study area. The 58 species were assigned individual indigenous names using folk taxonomy guidelines supplemented with guidelines for modern taxonomies.

CONCLUSIONS

There is a gap in the documentation and investigation of amphibian folk taxonomy in South Africa. Standardization of indigenous frog names is required to increase their universality. Similarities between folk and modern taxonomies allow for supplementation of indigenous guidelines when compiling a comprehensive indigenous species list. Through this study, social inclusion in wildlife matters is increased, indigenous knowledge systems are promoted, and a contribution is made to the development of an indigenous South African language.

Occurrence of Hepatozoon canis (Adeleorina: Hepatozoidae) and Anaplasma spp. (Rickettsiales: Anaplasmataceae) in black-backed jackals (Canis mesomelas) in South Africa

Background

Domestic dogs are not native to sub-Saharan Africa, which may account for their susceptibility to Babesia rossi, of which endemic black-backed jackals (Canis mesomelas) are natural reservoirs. There is virtually no information on the occurrence of potentially pathogenic haemogregarines (e.g. Hepatozoon canis) or even rickettsial bacteria (e.g. Ehrlichia spp. and Anaplasma spp.) in indigenous canids in sub-Saharan Africa. Such organisms could pose a risk to domestic dogs, as well as to populations of endangered indigenous canid species.

Results

Genomic DNA extracted from blood samples taken from 126 free-ranging and 16 captive black-backed jackals was subjected to reverse line blot (RLB) hybridization assay; 82 (57.8%) specimens reacted only with the Ehrlichia/Anaplasma genera-specific probe. Full-length bacterial 16S rRNA gene of five of these specimens was cloned and the recombinants sequenced. The ten 16S rDNA sequences obtained were most closely related, with approximately 99% identity, to Anaplasma sp. South African Dog, various uncultured Anaplasma spp., as well as various Anaplasma phagocytophilum genotypes. Ninety-one specimens were screened for haemogregarines through PCR amplification using the 18S rRNA gene; 20 (21.9%) specimens reacted positively, of which 14 (15.4%) were confirmed positive for Hepatozoon genotypes from within H. canis. Two (2.2%) specimens were found positive for two different Hepatozoon genotypes.

Conclusions

Sequence analyses confirmed the presence of 16S rDNA sequences closely related to A. phagocytophilum and Anaplasma sp. South African Dog as well as two H. canis genotypes in both free-ranging and captive black-backed jackals. Distinguishing between closely related lineages may provide insight into differences in pathogenicity and virulence of various Anaplasma and H. canis genotypes. By building up a more comprehensive understanding of the range and diversity of the bacteria and eukaryotic organisms (piroplasms and haemogregarines) in the blood of indigenous canids, we may gain insight to such infections in these often-endangered species and the potential for horizontal transmission to and from domestic dogs via ticks where favourable conditions exist.

Drought-associated absence of alien invasive anchorworm, Lernaea cyprinacea (Copepoda: Lernaeidae), is related to changes in fish health

Recently, Mozambique tilapia (Oreochromis mossambicus Peters, 1852) were listed on the IUCN Red List as near-threatened as their populations are at risk due to hybridization. Another factor that potentially contributes to their population decline is that they are regularly infected by the invasive parasitic copepod anchorworm, Lernaea cyprinacea Linnaeus, 1758. Considering anchorworm-infected Mozambique tilapia are common, understanding their condition with respect to infection is difficult as uninfected fish from the same localities have been unavailable for comparison. A severe drought in southern Africa has created hypersaline environments in the Phongolo River floodplain of north-eastern South Africa, such that freshwater parasites cannot survive and uninfected fish are now found. To determine how infection influences host health, infected and uninfected Mozambique tilapia were collected before and during drought conditions, from Nyamiti pan of the Phongolo River floodplain. Anchorworm-infected fish prevalence was recorded, and anchorworms were collected from hosts and identified to the species level using molecular data of the 18S rRNA gene. For each fish, intensity of anchorworm infection, total length, and weights of the gutted body, liver, spleen, and gonads were recorded. Gutted condition factor, hepato-, spleeno-, and gonado-somatic index values per fish, and prevalence of infection per collection were determined. A rapid health assessment was also conducted to determine a health score for each fish. Molecular analyses confirmed the anchorworm studied was L. cyprinacea. Prior to and during drought, prevalence of infection was 100%, and 0%, respectively. Before drought, fish had significantly reduced hepato-, spleeno-, and gonado-somatic index values, and higher health assessment scores, yet significantly higher gutted condition. Anchorworm intensity was indirectly correlated with fish liver and gonad condition. This study demonstrates that host condition and health varies greatly with respect to drought and infection, and provides the necessary data for follow-up studies in post-drought conditions.

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Invasive Lernaea cyprinacea, confirmed by 18S rRNA data, infect Mozambique tilapia.

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Severe drought has induced a natural freshwater ectoparasite removal treatment.

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Prevalence of anchorworm-infected tilapia was 100% before and 0% during drought.

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Anchorworm infection is related to reduced fish health and some host energetics.

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Accordingly infection may alter host fitness and population dynamics.

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.

Hepatozoon species (Adeleorina: Hepatozoidae) of African bufonids, with morphological description and molecular diagnosis of Hepatozoon ixoxo sp. nov. parasitising three Amietophrynus species (Anura: Bufonidae)

Background

Haemogregarines comprise a large group of apicomplexan blood parasites. In 1996 all anuran haemogregarines still in the genus Haemogregarina Danilewsky, 1885 were reassigned to the genus Hepatozoon Miller, 1908. Most (11/15, 73%) African anuran Hepatozoon species have been recorded from the family Bufonidae, however, all these are recorded from only two host species, Amietophrynus mauritanicus (Schlegel, 1841) and Amietophrynus regularis (Reuss, 1833) from Northern and central Africa. To the authors’ knowledge the only description of an anuran haemogregarine from South Africa is Hepatozoon theileri (Laveran, 1905), parasitising Amietia quecketti (Boulenger, 1895).

Methods

Thin blood smears for morphometrics and whole blood for molecular work, were collected from 32 Amietophrynus garmani (Meek, 1897), 12 Amietophrynus gutturalis (Power, 1927), and nine Amietophrynus maculatus (Hallowell, 1854), in Ndumo Game Reserve and Kwa Nyamazane Conservancy, KwaZulu-Natal, South Africa. Smears were Giemsa-stained, screened for haemogregarines, parasite stages measured, compared to each other and to other described African bufonid haemogregarines. Parasite 18S rDNA was amplified using two apicomplexan-specific primer sets, HepF300/HepR900 and 4558/2733. Resulting sequences of the haemogregarine isolates from the three Amietophrynus species were compared with each other and to comparative haemogregarine sequences selected from GenBank.

Results

Morphological characteristics of parasite stages, in particular characteristically capped mature gamont stages, and molecular findings, supported all three haemogregarine isolates from all three Amietophrynus species to be the same, a species of Hepatozoon, and furthermore different morphologically from other previously recorded bufonid Hepatozoon species. The haemogregarine fell within a clade comprising other anuran Hepatozoon species and furthermore, within a monophyletic sub-clade along with H. theileri and are described as Hepatozoon ixoxo sp. nov.

Conclusions

This is the first morphological and molecular account of Hepatozoon species within the family Bufonidae from South Africa, a study hoped to encourage the redescription and molecular analysis of those Hepatozoon species described in the past from Amietophrynus species, as well as to promote the use of both morphological and molecular characteristics in Hepatozoon species descriptions. This will aid in comprehensive Hepatozoon descriptions, which along with the use of phylogenetic analysis will give a better indication of these parasites possible vectors and life cycle dynamics.

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.