Occurrence of the host-parasite system Rhaphiodon vulpinus and Ceratomyxa barbata n. sp. in the two largest watersheds in South America

While around world, species of the genus Ceratomyxa parasite majority marine hosts, growing diversity has been reported in South American freshwater fish. The present study reports Ceratomyxa barbata n. sp. parasitizing the gallbladder of the Rhaphiodon vulpinus fish from the Amazon and La Plata basins. Morphological (light and transmission electron microscopy), molecular (sequencing of small subunit ribosomal DNA - SSU rDNA), and phylogenetic analyses were used to characterize the new species. Worm-like plasmodia endowed with motility were found swimming freely in the bile. The myxospores were elongated, lightly arcuate, with rounded ends and had polar tubules with 3 coils in the polar capsules. Ultrastructural analysis revealed plasmodia composed of an outer cytoplasmic region, where elongated tubular mitochondria, a rough endoplasmic reticulum, sporogonic stages, and a large vacuole occupying the internal area were observed. Phylogenetic analysis, based on SSU rDNA, found that among all South America freshwater Ceratomyxa species, C. barbata n. sp. arises as an earlier divergent species. The present study reveals the occurrence of this host-parasite system (R. vulpinus/C. barbata n. sp.) in the two largest watersheds on the continent.     

Molecular and Morphometric Characteristics of Ceratomyxa hamour n. sp. (Myxosporea: Bivalvulida) Infecting the Gallbladder of the Orange‐spotted Grouper Epinephelus coioides from the Arabian Gulf,Saudi Arabia

Ceratomyxa hamour n. sp. was found to infect the gallbladder of the orange‐spotted grouper, Epinephelus coioides located off the Saudi Arabian coast of the Arabian Gulf. The infection was reported as a free‐floating spore in the bile, and pseudoplasmodia were not observed. Mature spores were crescent‐shaped and measured on average 7 μm in length and 16 μm in thickness. The polar capsule, meanwhile, had length to width measurements of 4 μm and 3 μm on average. A periodical survey was conducted throughout a sampling period between December 2012 and December 2013, with the results showing that the parasite was present throughout the year with a mean prevalence of 32.6%. The objective of this study was to characterize this new species based on its morphological and molecular differences from previously described species. Molecular analysis based on the partial sequence of the SSU rDNA gene, showed the highest similarity (97.8%) to Ceratomyxa buri, reported in the cultured yellow tail Seriola quinqueradiata in Japan. Indeed, C. buri and the new species described here formed an individual cluster with a high degree of bootstrap support. This is the first reported species of genus Ceratomyxa from the Arabian Gulf fishes off Saudi Arabia.     

Ceratomyxa tunisiensis n. sp. (Myxosporea: Bivalvulida) from the Gallbladders of Two Carangid Fish Caught Off the Coast of Tunisia

A new coelozoic Myxozoan species, Ceratomyxa tunisiensis n. sp., was found infecting the gallbladders of two carangid fish, Caranx rhonchus and Trachurus trachurus (Perciforme, Carangidae), from the Gulf of Gabès, on the southern coast of Tunisia. The parasite develops in spherical mono‐, diplo‐, or polysporic tropozoites in the gallbladder of the hosts. Mature spores are typical of the genus Ceratomyxa. They are transversely elongated and narrowly crescent‐shaped with a slightly convex anterior and concave posterior, and measure 23 ± 0. 27 (20–25) μm width × 6 ± 0.26 (5–8) μm in length. Spore shell valves are symmetrical with rounded ends. Two spherical polar capsules situated on either side of the sutural line measure 2.2 μm (2.0–3.0) in diam. Periodical sampling of C. rhonchus and T. trachurus from Marsh 2012 to February 2013 showed that infection due to C. tunisiensis occurs in 59% and 69% of the examined fish, respectively. Molecular analysis based on the small subunit (SSU) rRNA sequence shows high genetic divergence with all other ceratomyxid species. A Maximum Likelihood phylogenetic tree shows association with the species C. leatharjecketi Fiala, kova, Kodadkova, Freeman, Barto?ova‐Sojkova, and Atkinson, 2015 reported from the gallbladder of Aluterusmonoceros (L.) caught in the Andaman Sea, off Malaysia. Nonetheless, the SSU rRNA sequences of C. tunisiensis and C. leatharjecketi have only a 90% similarity.     

Huffmanela selachii n. sp. (Nematoda: Trichosomoididae: Huffmanelinae): A new species infecting the skin of the great hammerhead shark (Sphyrna mokarran) and the blacktip reef shark (Carcharhinus melanopterus) in the Arabian Gulf,off-shore Saudi Arabia

From January 2017 - December 2019, 75 out of 850 (8.8 %) great hammerhead sharks from the Arabian Gulf had skin lesions of black irregular discolorations on the ventral surface of the head. The lesions consisted of pencil-like lineations often advancing forward by about 2 mm in back-and-forth looped scribbles often forming a relatively linear bands of about 5–7 cm wide. Similar lesions were also found in the blacktip reef shark from the same area within the same period, and consisted of straight to irregular black lines, extended indiscriminately across the skin of the sharks. Microscopic examination of the skin revealed the presence of dark-brown eggs exhibiting the spindle or ellipsoidal eggs characteristic of Huffmanela sp. The morphometrics of eggs from both hosts were similar (62.9–89.9 μm long and 29.3–56.1 μm wide). The eggshells were smooth with polar plugs protruding or not, with an abruptly truncated crown-like or shoulder-like collar surrounding the plug. The eggs were only found in the epidermal layer of the skin. Based on the unique morphometrics of the eggs, we report a new species, named: Huffmanela selachii n. sp.. This appears to be the first report of Huffmanela from either the great hammerhead shark or the blacktip reef shark, and the third reported Huffmanela in sharks from the Arabian Gulf. It is also one of few species reported from connecting waters of the greater Indian Ocean. This new finding contributes to our understanding of the diversity and ubiquity of Huffmanela sp. in marine creatures.     

Molecular data and phylogenetic analysis of Myxobolus pseudonobilis n. sp. infecting the gill filaments of silver carp,Hypophthalmichthys molitrix Valenciennes, 1844

In the present study, we combined morphological and phylogenetic methods to characterize Myxobolus pseudonobilis n. sp. infecting Hypophthalmichthys molitrix Valenciennes, 1844 from Chongqing, China. The morphology and molecular characteristics of M. pseudonobilis n. sp. were distinct from those of other previously described Myxobolus species. Mature myxospores were ovoid in frontal view with spore dimensions of 10.0 ± 0.4 (9.3–10.9) μm in length and 8.5 ± 0.2 (7.9–9.0) μm in width. Two polar capsules occupying approximately half of the myxospore length were unequal in size. The larger polar capsule containing 6 to 7 filament coils measured 5.2 ± 0.3 (4.5–5.8) μm in length and 3.6 ± 0.2 (3.2–3.9) μm in width, while the smaller capsule with 4 to 5 filament coils measured 3.9 ± 0.3 (3.0–4.4) μm in length and 2.5 ± 0.3 (2.1–3.6) μm in width. The comparison of molecular characteristics demonstrated similarities and genetic distances of 18S rDNA sequences of 95.19% - 98.20% and 1.82% - 5.46%, respectively, between M. pseudonobilis n. sp. and its morphologically similar species, and secondary structures were also distinctly different. Moreover, phylogenetic analysis showed that M. pseudonobilis n. sp. was clustered with other myxobolids possessing spores with a blunt anterior end and branched independently. In addition, the morphology of myxosporeans as an important indicator was discussed.     

Sphaerospora ictaluri N. Sp. (Myxosporea: Sphaerosphoridae) Observed in the Kidney of Channel Catfish, Ictalurus punctatus Rafinesque

Sphaerospores were found in the kidneys of alevin channel catfish (Ictalurus punctatus) from a farm in Central California. MulticelluUr developmental stages, similar to C-blood protozoans described for Sphaerospora spp. from cyprinid fishes, were observed in circulating blood and numerous tissues. Upon a 2nd examination of the same population offish 10 days later, sporogonic stages were seen developing into mature Sphaerospores in the lumina of the kidney tubules. Sporogeoesis was asynchronous with simple unicellular stages adjacent to more complex forms with developing polar capsules and valves. Only one elliptical spore (5.6 μm in width, 6.5 μm in thickness by 5.8 μm in length) developed within the surrounding pscudoplasmodium. Thin valves surrounded two sporoplasm cells and two subspherical polar capsules (1.7 × 1.9 μm) which contained a polar filament with four to five turns. The blood stages of the Sphaerospora sp. described here are similar to the trophozoites seen in channel catfish with proliferativc gill disease (PGD). Early stages of PGD also observed in the same population of channel catfish containing developmental and sporogonic stages of this newly recognized Sphaerospora sp. may suggest a causal relationship between this new myxosporean and the gill disease.     

Ortholinea nupchi n. sp. (Myxosporea: Ortholineidae) from the urinary bladder of the cultured olive flounder Paralichthys olivaceus,South Korea

A new myxosporean parasite, Ortholinea nupchi n. sp. (Myxozoa; Bivalvulida), was isolated from the urinary bladder of the olive flounder Paralichthys olivaceus cultured on Jeju Island, Korea. Mature spores were subspherical in the valvular and apical views and ellipsoidal in the sutural view. The spores measured 7.6 ± 0.5 μm in length, 6.7 ± 0.3 μm in thickness, and 7.3 ± 0.5 μm in width. Two pyriform polar capsules measured 3.2 ± 0.1 μm in length and 2.7 ± 0.1 μm in width and were located at the same level at the anterior half of the myxospores. The suture line was straight in the middle of the spores, and the surface ridges ranged between five and seven, forming an intricate pattern. The result of the 18S rDNA comparison showed ≤ 93.0% similarity with other Ortholinea species. The phylogenetic tree demonstrated that O. nupchi n. sp. was closest to O. auratae and clustered with oligochaete-infecting myxosporeans (OIM) having urinary system infection tropism. Based on the comparison of environmental and host factors in the phylogenetic groups of the OIM clade, we propose that the infection of O. nupchi n. sp. originated from marine oligochaetes.     

Novel Myxobolus and Ellipsomyxa species (Cnidaria: Myxozoa) parasiting Brachyplatystoma rousseauxii (Siluriformes: Pimelodidae) in the Amazon basin,Brazil

We describe two novel myxosporean parasites from Brachyplatystoma rousseauxii, an economically important freshwater catfish from the Amazon basin, Brazil. Myxobolus tapajosi n. sp., was found in the gill filaments of 23.5% of 17 fish, with myxospores round to oval in frontal view and biconvex in lateral view: length 15 (13.5–17) μm and width 10.7 (9.6–11.4) μm; polar capsules equal, length 5.8 (4.6–7.1) μm and width 3 (2.3–3.8) μm containing polar tubules with 6–7 turns. Ellipsomyxa amazonensis n. sp. myxospores were found floating freely or inside plasmodia in the gall bladder of 23.5% of fish. The myxospores were ellipsoidal with rounded extremities: length 12.8 (12.3–13.6) μm and width 7.6 (6.7–8.7) μm; with two equal, slightly pyriform polar capsules, length 3.8 (3.8–4.0) μm and width 3.1 (2.5–3.4) μm, containing polar tubules with 2–3 turns. We combined spore morphometry, small-subunit ribosomal DNA data, specific host, and phylogenetic analyses, to identify both of these parasites as new myxozoan species. Maximum likelihood and Bayesian analyses showed that Myxobolus tapajosi n. sp. clustered in a basal branch in a subclade of parasites from exclusively South American pimelodid fishes. Ellipsomyxa amazonensis n. sp. clustered within the marine Ellipsomyxa lineage, but we suspect that although the parasite was collected in freshwater, its hosts perform a large migration throughout the Amazon basin and may have become infected from a brackish/marine polychaete host during the estuary phase of its life.     

Ellipsomyxa tucujuensis n. sp. (Myxozoa: Ceratomyxidae), a parasite of Satanoperca jurupari (Osteichthyes: Cichlidae) from the Brazilian Amazon

The present study describes a new coelozoic, eukaryotic microparasite of the genus Ellipsomyxa Køie, 2003 (Ceratomyxidae: Myxozoa) found parasitizing the gallbladder of Satanoperca jurupari Heckel, 1840 collected in the Curiaú River Environmental Protection Area in Macapá, Amapá state, Brazil. The fish were collected using mesh cast net. The gallbladders were examined, preserved in 80% alcohol for molecular analysis (SSU rDNA gene), and fixed in Davidson for histological slide preparation. The new parasite had a prevalence of 81% in the gallbladder, asymmetric plasmodia, irregular free spores in the bladder fluid, with no cyst formation. The spores are elliptical, with characteristics of the genus Ellipsomyxa, and they had a mean length of 10.11 (8.56–10.5) μm, mean width of 7.81 (5.96–9.56) μm, and thick walls. The polar capsules are sub-spherical in shape, slightly asymmetrical, with a mean length of 3.12 (2.31–3.99) μm and mean width of 2.5 (2.22–2.95) μm, containing polar filament with five or six coils perpendicular to the longitudinal axis of the capsule. The Bayesian Inference assigned the new species to a subclade formed by a lineage of Ellipsomyxa species from the Amazon region. Ellipsomyxa tucujuensis n. sp. is the sixth species of this genus described in fish from the Amazon region, and the first for the state of Amapá.     

Morphological and molecular analysis of Henneguya lagunensis n. sp. (Cnidaria,Myxosporea) parasitizing the gills of Eugerres brasilianus from Brazil

Plasmodia containing myxospores belonging to the genus Henneguya Thélohan, 1892 were found in the gills of Eugerres brasilianus (Cuvier, 1830). Despite the economic importance, few parasitological studies have been done with this species. We describe Henneguya lagunensis n. sp. using morphological and molecular data. The mature myxospores were rounded, measuring 29.1 ± 2.2 μm in total length, 8.2 ± 1.0 μm in body length, 7.9 ± 0.2 μm in body width, 20.7 ± 2.4 μm in tail length and 4.8 ± 1.0 μm in thickness. The polar capsules measured 3.3 ± 0.4 in length and 1.7 ± 0.3 μm in width. Polar filaments had 4–5 turns, helical. Phylogenetic analysis showed Henneguya lagunensis n. sp. as a sister species of Henneguya cynoscioni Dyková, Buron, Roumillat and Fiala, 2011, within a clade that contained mostly Henneguya species that parasitize marine fish of the order Perciformes. This is the first report of a species of Henneguya parasitizing Eugerres brasilianus.     

The subfamily Encotyllabinae (Monogenea: Capsalidae) with the description of Alloencotyllabe caranxi n. g., n. sp. and Encotyllabe kuwaitensis n. sp.

Alloencotyllabe caranxi n. g., n. sp. is found in groups of 9–15 specimens attached close together to the lower pharyngeal plate of Caranx sp. It is characterized by having an elongate body, a prohaptor with large spines, an armed penis which lies in a pouch and a vaginal pouch guarded by two sets of glands. Encotyllabe kuwaitensis n. sp. is attached individually to the lower pharyngeal plate of Caranx sp. It is characterized by having an elongate body and tandem testes. E. spari is reported from the lower pharyngeal tooth plate of Plectorhynchus cinctus, P. pictus and P. schotaf. All fish hosts were caught in Kuwaiti waters in the Arabian Gulf. The subfamily Encotyllabinae is reviewed and the genus Neoencotyllabe is regarded as a genus inquirendum. The new genus is attached to the subfamily Encotyllabinae.     

Morphology and molecular phylogeny of Hoferellus jutubensis n. sp. (Cnidaria: Myxozoa) found parasitising Ageneiosus inermis (Siluriformes: Auchenipteridae), in the Brazilian Amazon region

The present study describes Hoferellus jutubensis n. sp., a myxozoan parasite found in the urinary bladder of the driftwood catfish Ageneiosus inermis, captured on Jutuba Island in the state of Pará, northern Brazil. A total of 30 A. inermis specimens were examined, of which 26 (86.7%) had myxospores and polysporic plasmodia of varying shapes and sizes dispersed in the lumen of the urinary bladder, either floating freely or attached to the epithelium. In the apical view, the myxospores of Hoferellus jutubensis n. sp. are rounded, 6.1 ± 0.2 (5.7–6.3) μm long and 5.5 ± 0.3 (5.2–6.0) μm wide, with two sub-spherical polar capsules, equal in size and shape, 2.5 ± 0.2 (2.3–2.7) μm long and 1.7 ± 0.2 (1.4–2.2) μm wide. The phylogenetic analysis of a partial sequence of the SSU rDNA gene, indicated that the new species is the sister taxon of Hoferellus azevedoi, with these two species forming a Brazilian lineage of Hoferellus. The comparison of the morphological and molecular data with those of the existing members of the genus confirmed the species status of Hoferellus jutubensis n. sp., which adds one further Hoferellus taxon to the known myxosporean diversity of the Amazon basin.     

Sphaeromyxa maiyai sp. n. (Protozoa: Myxosporidea), Coelozoic Parasite of the Pacific Tomcod,Microgadus proxiimus*

SYNOPSIS. Sphaeromyxa maiyai sp. n. (Myxosporidea: Myxiidae) is described from the gall bladder of the Pacific tomcod Microgadus proximus Girard, from Newport, Oregon. The plasmodial stage is discoid averaging between 1 and 2 cm. The spore averages 27.6 × 5.6 μm in breadth, with pyriform polar capsules measuring 9.3 × 3.7 μm. Scanning electron microscopy reveals the presence of numerous longitudinal striations.     

Three new coccidians (<Emphasis Type="Italic">Cyclospora</Emphasis>, <Emphasis Type="Italic">Eimeria</Emphasis>) from eastern moles, <Emphasis Type="Italic">Scalopus aquaticus</Emphasis> (Linnaeus) (Mammalia: Soricomorpha: Talpidae) from Arkansas,USA

Three new species of coccidians (Apicomplexa: Eimeriidae) are described from eastern moles, Scalopus aquaticus (Linnaeus) from Arkansas. Oöcysts of Cyclospora duszynskii n. sp. are subspheroidal with a smooth bi-layered wall, measure 11.4 × 10.0 µm, and have a length/width (L/W) ratio of 1.1; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 7.2 × 5.4 µm, L/W 1.3; an indistinct Stieda body is present, but the sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. Oöcysts of Cyclospora yatesi n. sp. are subspheroidal to ovoidal with an ornate outer wall, measure 17.0 × 15.2 µm, L/W 1.1; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 9.7 × 7.3 µm, L/W 1.3; an indistinct Stieda body is present, but sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. Oöcysts of Eimeria paulettefordae n. sp. are ovoidal to ellipsoidal with an ornate outer wall, measure 30.0 × 25.4 µm, L/W 1.2; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 12.6 × 9.2 µm, L/W 1.4; a button-like Stieda body is present, but sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. These are the first coccidians described from Arkansas populations of S. aquaticus. In addition, a summary is provided on the cyclosporans and eimerians from North American talpids.     

<Emphasis Type="Italic">Myxobolus imparfinis</Emphasis> n. sp. (Myxozoa: Myxosporea), a new gill parasite of <Emphasis Type="Italic">Imparfinis mirini</Emphasis> Haseman (Siluriformes: Heptapteridae) in Brazil

A new species of myxozoan, Myxobolus imparfinis n. sp. is described based on material from the gills of Imparfinis mirini (Haseman) (Heptapteridae). Mature myxospores are round, measuring 7.1–8.4 (7.9 ± 0.3) μm in length, 4.5–6.2 (5.5 ± 0.5) μm in width and 3.1–4.2 (3.7 ± 0.3) μm in thickness. The polar capsules are of unequal size, the larger polar capsule measuring 3.4–4.5 (3.9 ± 0.3) μm in length and 1.4–2.0 (1.7 ± 0.1) μm in width and the smaller capsule measuring 3.1–3.8 (3.4 ± 0.2) μm in length and 1.2–1.8 (1.5 ± 0.2) μm in width. The polar filament presents 6–7 coils. Spores had a prevalence of infection of 75% (6/8). In histological analyses we detected the development site of spores in primary filaments, in afferent branchial artery, thus classifying the type of infection to the filamental type and vascular subtype. The phylogenetic analyses of a dataset including species Myxobolus Bütschli, 1882 and Henneguya Thélohan, 1892 from South America recovered M. imparfinis n. sp. as a sister species of Myxobolus flavus Carriero, Adriano, Silva, Ceccarelli & Maia, 2013. To our knowledge, this is the first record of a myxozoan species parasitising I. mirini.     

Ultrastructural aspects and molecular phylogeny of <Emphasis Type="Italic">Auerbachia maamouni</Emphasis> n. sp. (Myxosporea: Bivalvulida) from the gallbladder of <Emphasis Type="Italic">Gnathanodon speciosus</Emphasis> Forsskål (Actinopterygii: Carangidae) in the Red Sea

A new myxosporean parasite, Auerbachia maamouni n. sp., infecting the gallbladder of the golden trevally Gnathanodon speciosus Forsskål, is described, based on morphology, ultrastructure, and small subunit (SSU) rRNA gene sequencing. Of 50 fish collected from the Red Sea in Jeddah, Saudi Arabia, five were found heavily infected with mature myxospores floating free in the bile. Mature spores are pyriform to club-shaped with smooth valves, and contain a single polar capsule with an S-shaped polar filament, arranged in 13–16 polar filament coils, oriented longitudinally, with an irregular distribution on the polar capsule matrix. Spores measure 15.8 (14–17) μm in total length in lateral view, 7.9 (6–9) μm in width in apical view, with spore body length of 6.2 ± 0.4 (5–7) µm. The ellipsoidal polar capsule has two adjusted lateral folds 7.6 (6–8) µm long and 2 (2–3) µm wide. The new species is distinguished from other species of the genus based on spore morphometry and molecular data. The phylogenetic tree constructed using Maximum Likelihood and Bayesian Inference analysis of SSU rDNA sequence data supported the phylogenetic position of A. maamouni n. sp. among the species of Auerbachia Meglitsch, 1968 sequenced to date. Analysis of the SSU rDNA sequence data also supported the assumption that Auerbachia is closely related to members of the genera Coccomyxa Léger & Hesse, 1907, Zschokkella Auerbach, 1910 and Myxidium Bütschli, 1882, whose members inhabit the gallbladder of marine teleost fishes.     

A review of the trypanosomes from lizards of the family Iguanidae (sensu lato), including the descriptions of five new species, and an evaluation of the effect of host difference upon taxonomic characters of saurian trypanosomes

Five new species of Trypanosoma are described from iguanid lizards. In Texas, T. poinsetti n. sp. occurs in Sceloporus poinsetti and T. urosauri n. sp. in Urosaurus graciosus. Average dimensions of T. poinsetti are body length (BL) 35.7 × maximum width (MW) 10.7 µm, nucleus length (NL) 4.3 µm, position of kinetoplast (K%) 70.6, position of nucleus (N%) 61.9, ratio of BL: MW (SI) 3.4, and ratio (NI) of NL to nucleus width (NW) 1.5. In T. urosauri average dimensions are BL 34.3 × MW 6.3 µm, NL 2.4 µm, K% 57.5, N% 66.2, SI 5.6, and NI 1.3. Trypanosomes with small compact nuclei that parasitise four Anolis species from Belize to Panama are assigned to T. anolisi n. sp. Average dimensions from the type sample in Anolis limifrons of Panama are BL 24.6 × MW 17.9 µm, NL 2.1 µm, K% 82.0, N% 78.4, SI 1.6 and NI 1.1. T. fairchildi n. sp., from Anolis capito of Panama, is a large, tongue- or leaf-shaped flagellate with BL 49.2 × MW 28.8 µm, NL 2.0 µm, K% 75.6, N% 64.5, NL 2.0, SI 1.9 and NI 1.6. Dimensions of T. plicaplicae n. sp., from Plica plica of Guyana, average BL 30.9 × MW 19.9 µm, NL 7.2 µm, K% 75.8, N% 56.2, SI 1.6 and NI 2.3. In the United States, T. scelopori parasitises Sceloporus occidentalis and Crotaphytus collaris in California. Trypanosomes with an elongate slender nucleus found in lizards of the genera Sceloporus and Corytophanes from Veracruz, Mexico to Panama, and in Anolis probably as far as Peru, are all considered to be T. serveti. Other species may be present, but cannot be separated on the basis of consistent morphometric characters. Two additional species are known from endemic South American saurian genera: T. plicae occurs in Plica umbra and T. superciliosae in Uranoscodon superciliosa of Brazil. T. domerguei is known from the Madagascan iguanid, Oplurus sebae. Only T. scincorum of southeast Asian skinks lacks host effect upon morphological characters throughout its range. Samples from two hosts each of T. anolisi in Panama and T. uluguruense in Tanzania differed in only two of 10 characters analysed, suggesting little host effect. Other comparisons of iguanid and gekkonid trypanosomes suggested that differences in parasite strain rather than host might contribute to observed variation.     

Description of the oöcysts of Eimeria beccari n. sp. (Apicomplexa: Eimeriidae) from Varanus prasinus beccari (Reptilia: Varanidae)

Eimeria beccari n. sp. is described from the faecal contents of Varanus prasinus beccari (Reptilia: Varanidae), originally from the Aru Islands northwest of New Guinea. Oöcysts are cylindroid, 33.7 × 19.1 (29–36 × 18–21) µm, often with one end narrowing; shape index (length/width) 1.76 (1.6–1.9). A micropyle and oöcyst residuum are absent but a polar granule is present in most oöcysts. Sporocysts are ellipsoid, 12.0 × 7.7 (11–13.5 × 7–8) µm; shape index 1.56 (1.5–1.7). Stieda and substieda bodies are absent. Sporozoites are elongate, 10.4 × 2.8 (9–12 × 2.5–3) µm, and contain a posterior refractile body.