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The curious skink, Carlia ailanpalai Zug, occurs in the main group of the Admiralty Islands of Papua New Guinea but has also successfully invaded Guam, the Marianas, Yap, and Kosrae. A single coccidian, Eimeria zugi McAllister, Duszynski, Fisher, & Austin, 2013 was described from C. ailanpalai from Papua New Guinea. No additional coccidians are known from this host. Fourteen C. ailanpalai were collected from Cocos Island (Islan Dåno), Guam, U.S. Territory, and their feces examined for coccidians. A single skink (7%) was found to be passing oöcysts of a new species of Choleoeimeria. Oöcysts of Choleoeimeria cocosensis n. sp. are ellipsoidal to ovoidal with a bi-layered wall, measure (L × W) 21.1 × 12.9 µm, and have a length/width (L/W) ratio of 1.6; a micropyle and an oocyst residuum were absent but fragmented polar granule(s) was present. Sporocysts are ovoidal and measure 8.6 × 6.3 µm, L/W 1.4; Stieda, sub-Stieda, and para-Stieda bodies were absent. Sporocyst residuum was typically a loose aggregate of various-sized granules between and across the sporozoites but sometimes a dense irregular mass between and across the sporozoites. Sporozoites were elongate, with a centrally located nucleus and a large spheroidal to subspheroidal posterior refractile body, but without an anterior refractile body. The new species can be differentiated from all other choleoeimerians from skinks by possessing one of the smallest oöcysts known from the host family. We also provide an updated summation of the choleoeimerians from skinks of the world. This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:6EFDF027-0A92-43C4-9AD0-E555252E7741., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Octomacrum spinum Dansby & Shoemaker, 1973, is reported for the first time from 23 of 146 (16%) highland stonerollers, Campostoma spadiceum collected from central and western Arkansas and southeastern Oklahoma, USA. Analysis of molecular data revealed that the SSU rRNA gene of specimens of O. spinum from Arkansas was identical to a number of Octomacrum spp. and the LSU rRNA gene was 97.46% similar to Octomacrum europaeum. We also provide a summary of the species of Octomacrum reported from North American and European fishes., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: Nothing is known about coccidians (Apicomplexa: Eimeriidae) from the Pacific blue-tailed skink, Emoia caeruleocauda. Here, we report mensural and morphometric data on a new species of Isospora from E. caeruleocauda from Guam, US Territory., Methods: Feces from four E. caeruleocauda collected by hand in November 2023 were placed in individual vials containing 2.5% potassium dichromate. They were examined for sporulated oocysts after flotation in Sheather's sugar solution, measured, and photographed., Results: A single (25%) E. caeruleocauda was found to be passing oocysts representing a new species of Isospora. Oocysts of Isospora guamensis n. sp. are ellipsoidal to ovoidal with a bi-layered wall, measure (L × W) 16.5 × 11.8 μm, and have a length/width (L/W) ratio of 1.4; a micropyle and an oocyst residuum were absent but a polar granule was present. Sporocysts are ovoidal and measure 9.4 × 6.5 μm, L/W 1.4; Stieda and sub-Stieda bodies were present but a para-Stieda body was absent. The sporocyst residuum is composed various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. The new species can be differentiated from all other isosporans from skinks by possessing the smallest oocysts known from this host family., Conclusion: This is the first time an isosporan coccidian has been reported from E. caeruleocauda as well as the first report of a coccidian from a Guam-inhabiting skink., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Two new species of lung-dwelling nematodes are described from North American frogs: Rhabdias aurorae n. sp. from Rana aurora and Rhabdias conni n. sp. from Rana clamitans and Rana catesbeiana from Arkansas; the latter species was also found in Oklahoma and Georgia. Rhabdias aurorae n. sp. differs from other Nearctic congeners in the combination of the following characteristics: buccal capsule 22-25 μm wide, elongated tail covered with inflated cuticle, esophagus with prominent dilatation in anterior part and 6 small circumoral lips. Rhabdias conni n. sp. is morphologically closest to Rhabdias ranae Walton, 1929 and Rhabdias joaquinensisIngles, 1936; it differs from them in the shape of lateral pseudolabia, the dimensions of the body, and the egg size. Both new species were found to be significantly different from the Nearctic congeners in the nucleotide sequences of nuclear ribosomal DNA (18S-ITS-28S region), 12S, and CO1 mitochondrial genes. The 2 new species differ from other currently sequenced Nearctic congeners by 1.1-2.7% of nucleotide positions in the nuclear rDNA region, 1.3-3.4% in the 12S gene, and 3.4-9.4% in CO1 gene. Molecular phylogenetic analysis based on nuclear ribosomal DNA sequences placed both new species into the clade consisting of Nearctic and Neotropical Rhabdias spp. The position of Rh. aurorae n. sp. within the clade is uncertain because of a polytomy, but Rh. conni n. sp. is nested within the "Rh. joaquinensis complex" related to Rh. ranae and Rhabdias tarichaeKuzmin, Tkach, and Snyder, 2003. The phylogenetic analysis based on nuclear ribosomal DNA sequences has revealed 3 evolutionary host-switching events from anuran to caudatan hosts among Rhabdias spp. that occurred in the Nearctic and Palearctic. The molecular phylogeny also suggests that Rhabdias may have originally evolved in what is now Africa., (© American Society of Parasitologists 2024.)

During March 2023, 7 green sunfish (Lepomis cyanellus) and 2 bluegill (Lepomis macrochirus) were collected from the Black River (White River drainage) in Lawrence County, Arkansas. In addition, during March 2023 and again in May-June 2023, 13 L. cyanellus and 6 L. macrochirus were taken from Butcherknife and Big Fork creeks (Ouachita River drainage), Polk County, Arkansas, 9 L. cyanellus were collected from the Caddo River, Montgomery County, Arkansas, and 5 green sunfish were taken from Clear Creek at Savoy, Washington County, Arkansas. All fish had their gill, gallbladder, fins, integument, musculature, and other major organs examined for myxozoans. The gill of 1 of 34 (3%) L. cyanellus was infected with a new myxozoan, Myxobolus fergusoni n. sp. Qualitative and quantitative morphological data were obtained from fresh myxospores, and molecular data consisted of a 1,933-base-pair sequence of the partial small subunit (SSU) ribosomal RNA (rRNA) gene. Phylogenetic analysis grouped M. fergusoni n. sp. with other centrarchid-infecting myxobolids from North America and placed this cluster in a larger clade comprising myxozoans that infect North American and European esocids, a North American aphredoderid, European percids, and a gasterosteid from Japan. Myxobolus fergusoni n. sp. infects the gill arches of L. cyanellus, similar to Myxobolus cartilaginis (Hoffman, Putz, and Dunbar, 1965), which was described from head cartilage, gill arches, and large fin rays of L. cyanellus. Another is Myxobolus mesentericusKudo, 1920, which was described from the viscera of green sunfish. A large polysporic plasmodium filled with myxospores was present in a basifilamental location associated with multiple gill filaments at their junction with the gill arch. The intact plasmodium replaced connective tissue within the arch but elicited only mild proliferation of overlying epithelium and a minimal host inflammatory response. This is the third time a myxozoan has been described from L. cyanellus, as well as being the first time it has been described from an Arkansas specimen., (© American Society of Parasitologists 2024.)

Clinostomum is a cosmopolitan genus of trematodes that infect piscivorous birds, freshwater molluscs, freshwater fish and amphibians. Herein, a novel species of Clinostomum is described based on morphological and molecular data from an adult in the oral cavity of the great blue heron Ardea herodias and metacercariae collected from the gills and skin of American bullfrog tadpoles Rana catesbeiana. The novel species shares similar qualitative and quantitative morphological features with a congener, Clinostomum marginatum, which has overlap in host and geographic distribution. The most notable morphological difference when compared to C. marginatum is the greater posterior testis length of the novel species. Molecular data resolved similarities with morphological comparisons to nominal species and supports the establishment of a novel species. Molecular data include partial small ribosomal subunit (18S rRNA gene), ribosomal internal transcribed spacer regions (ITS1, 5.8S rRNA gene, and ITS2), partial large ribosomal subunit (28S rRNA gene), cytochrome c oxidase subunit 1 gene (cox1), and nicotinamide adenine dinucleotide dehydrogenase subunit 1 gene (nad1) sequences. Phylogenetic analyses place the novel species in a sister clade to C. marginatum. Morphological and molecular data, combined with phylogenetic analyses support the establishment of Clinostomum dolichorchum n. sp., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

We report the morphological characteristics of oocysts of Eimeria lancasterensisJoseph, 1969, collected from 6 of 6 (100%) eastern gray squirrels, Sciurus carolinensis, collected in Arkansas (n = 3) and Oklahoma (n = 3), and Eimeria ontarioensisLee and Dorney, 1971, recovered from an individual of S. carolinensis from Arkansas. Oocysts of E. lancasterensis were ovoidal to ellipsoidal, measuring (L × W) 24.0 × 14.6 (18-29 × 12-16) µm; shape index (L/W) was 1.6 (1.3-1.8). A micropyle and an oocyst residuum were absent, but up to 2 polar granules were present. Oocysts of E. ontarioensis were piriform and measured 40.6 × 26.0 (37-44 × 23-28); L/W was 1.6 (1.5-1.7). These oocysts possessed a distinct micropyle and rarely a polar granule but lacked an oocyst residuum. The DNA was isolated from both eimerians, and the 18S rDNA genetic markers were PCR-amplified, cloned, sequenced, and analyzed. To our knowledge, this study represents the first time 18S DNA sequence data have been generated from E. lancasterensis and E. ontarioensis found in North American sciurid hosts, as well as new geographic distribution records for these coccidians. In addition, we also include a tabular summary of these 2 species of Eimeria from Sciurus spp. worldwide, with information on their hosts, distribution, and taxonomically important morphological characteristics, including key measurements of oocysts and sporocysts., (© American Society of Parasitologists 2024.)

Purpose: Little is known about the coccidian parasites of the American alligator, Alligator mississippiensis (Daudin). To date, only two species of Eimeria Schneider, 1875 have been previously reported from A. mississippiensis. Here, we report from mensural and morphometric data on two new species of Eimeria from A. mississippiensis from Georgia, USA., Methods: Fresh feces were collected in June 2023 from a single captive juvenile male A. mississippiensis. Multiple samples were placed in individual zip-lock bags and aqueous potassium dichromate was added. They were examined for sporulated oocysts after flotation in Sheather's sugar solution, measured, and photographed., Results: Samples contained oocysts representing two new species of Eimeria. Oocysts of Eimeria tellezae n. sp. are subspheroidal to ellipsoidal with a pitted bi-layered wall, measure (L × W) 34.5 × 31.5 µm, and have a length/width (L/W) ratio of 1.1; a micropyle and polar granule were absent but an oöcyst residuum was present. Sporocysts are ellipsoidal and measure 17.2 × 7.7 µm, L/W 2.2; a nipple-like Stieda body bearing one to several filaments was present but sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum is composed of various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. Oocysts of Eimeria daudini n. sp. are ellipsoidal with a pitted bi-layered wall, measure (L × W) 32.5 × 20.2 µm, and have a length/width (L/W) ratio of 1.6; a micropyle and polar granule were absent but an oöcyst residuum was present. Sporocysts are ellipsoidal and measure 15.4 × 7.4 µm, L/W 2.1; a nipple-like Stieda body bearing one to several filaments was present but sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum is composed of various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. Both new species can readily be distinguished from previously described eimerians from crocodilians, including those from A. mississippiensis., Conclusion: We document two new species of Eimeria from the American alligator. Currently, four species of Eimeria are known from A. mississippiensis examined from both east and west of the Mississippi River, USA., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

During May 2022 and again in March 2023, 5 quillbacks, Carpiodes cyprinus, were collected from the Verdigris River, Wagoner County, Oklahoma (n = 1), and the Black River, Lawrence County, Arkansas (n = 4), and their gill, gallbladder, fins, integument, musculature, and other major organs were macroscopically examined for myxozoans. Gill lamellae from the single quillback from the Verdigris River was infected with a new myxozoan, Thelohanellus oklahomaensis n. sp. Qualitative and quantitative morphological data were obtained from fresh and formalin-fixed preserved myxospores, and molecular data consisted of a 1,767 base pair sequence of the partial small subunit (SSU) ribosomal RNA gene. Phylogenetic analysis grouped T. oklahomaensis n. sp. with myxozoans known to infect North American catostomids and Eurasian cyprinids. Histological examination localized plasmodia to an intralamellar developmental site and revealed a possible vestige of a second polar capsule. Although plasmodia markedly expanded lamellae, there were no associated epithelial or inflammatory changes. Thelohanellus oklahomaensis n. sp. is the only member of the genus known to infect the gills of C. cyprinus., (© American Society of Parasitologists 2024.)

Tapeworms of the genus Ophiotaenia La Rue, 1911 parasitize herptiles (= amphibians and 'reptiles') throughout the world, with about 100 species recognised as valid. In the present work, the North American species found in watersnakes (Colubridae) are reviewed. An examination of the holotype of Ophiotaenia perspicua La Rue, 1911, the type species of the genus, and other specimens from Nerodia rhombifer (Hallowell) revealed that two species were used for the species description. The 'true' O. perspicua has a small scolex and small, round suckers. This species is redescribed based on new material from Oklahoma, USA. The other species from N. rhombifer , Ophiotaenia laruei n. sp., has a larger scolex and larger, almost triangular suckers. Examination of the types of O. variabilis (Brooks, 1978) from N. rhombifer and N. cyclopion (Duméril, Bibron et Duméril) from Louisiana, USA has revealed that it is a mixture of two or more species. Because of poor quality of these specimens, it is not possible to adequately characterise O. variabilis , which is considered a species inquirenda . In addition, two new species are described from Nerodia fasciata confluens (Blanchard). Ophiotaenia currani n. sp. from Mississippi, USA is characterised by elongate, narrow proglottids, few testes, and a relatively long cirrus sac. Ophiotaenia tkachi n. sp. from Louisiana, USA is characterised by relatively short and wide proglottids, more testes, and an unusual terminal part of the vagina with folds. Morphologically similar tapeworms of N. fasciata confluens , N. erythrogaster (Förster), N. sipedon (Linnaeus), and Agkistrodon piscivorus (Lacépède) (Viperidae) from Arkansas and Oklahoma, USA, which are genetically nearly identical, are considered to be conspecific with O. tkachi n. sp. The present data suggest a high, previously undescribed species diversity of proteocephalid tapeworms in watersnakes in North America, and generally strict host specificity of these tapeworms., Competing Interests: There is no conflict of interest in the submitted manuscript entitled “Discovering high species diversity of Ophiotaenia tapeworms (Cestoda: Proteocephalidae) of watersnakes (Colubridae) in North America”., (© 2023 The Authors.)

The northern cottonmouth, Agkistrodon piscivorus (Lacépède, 1789) (Viperidae: Crotalinae), occurs in the southeastern United States and is one of the few semiaquatic vipers in the world. Three proteocephalid tapeworms of the genus OphiotaeniaLa Rue, 1911 (Cestoda), have been described from this venomous snake. A critical evaluation of type specimens and tapeworms recently collected from A. piscivorus has revealed that only 2 species, Ophiotaenia marenzelleri (Barrois, 1898) and Ophiotaenia grandisLa Rue, 1911 (new synonym Ophiotaenia agkistrodontis [Harwood, 1933]), are specific parasites of this crotaline viper; both species are redescribed here. Ophiotaenia grandis was originally described from a mixture of 2 species: 'true' O. grandis, which is indistinguishable from O. agkistrodontis described 22 yr later and thus considered to be a junior synonym of O. grandis, and O. marenzelleri. Ophiotaenia marenzelleri, also reported from the pygmy rattlesnake, Sistrurus miliarius (Linnaeus, 1766), is a larger tapeworm with a massive scolex, a large cirrus sac, a very large, annular vaginal sphincter near the equatorial gonopore, and an oval, 3-layered embryophore surrounded by a nearly square hyaline outer membrane. Ophiotaenia grandis is much smaller and more slender and has a narrower scolex, a smaller cirrus sac and vaginal sphincter, a 2-layered embryophore, and a distinctly pre-equatorial gonopore. In addition to O. marenzelleri and O. grandis, other Ophiotaenia species typical of semiaquatic snakes (Colubridae: Natricinae) may be present in the northern cottonmouth, which serves only as a postcyclic or occasional host. There is also a tabular summary of 18 species of Ophiotaenia from semiaquatic snakes worldwide, with information on their hosts, distribution, and taxonomically important characters, including key measurements., (© American Society of Parasitologists 2023.)

The southern striped shiner, Luxilus chrysocephalus isolepis (Hubbs & Brown) is a relatively large minnow belonging to the true minnow family Leuciscidae Bonaparte. Between May 2020 and January 2022, 55 L. c. isolepis were collected from watersheds in Montgomery (n = 6), Polk (n = 17) and Sevier (n = 32) counties, Arkansas, USA, and their gills, gallbladders, urinary bladders, fins, integument, other major organs, and musculature were examined for myxozoans. Gills of 11 (34%) individual southern striped shiners from Sevier County were infected with a new myxozoan, Myxobolus carlhubbsi n. sp. A qualitative and quantitative morphological description was based on formalin-fixed preserved myxospores, and molecular data consisted of a 1,970 base pair sequence of the partial small subunit rRNA gene from ethanol-preserved specimens. Histologically, plasmodia filled and expanded interlamellar troughs. Hyperplastic epithelial and goblet cells filled interlamellar troughs adjacent to plasmodia, but inflammatory response was limited to scattered lymphocytes. Phylogenetic analysis revealed that M. carlhubbsi n. sp. is a member of a clade of species with pyriform myxospores parasitizing North American Pogonichthyinae Girard and North American and Eurasian Leuciscinae Bonaparte. This is the first report of a myxozoan from L. c. isolepis. This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:D10D71C2-2C75-4A1C-80ED-B98FF36CB509., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Proteocephalid tapeworms of frogs of the family Ranidae ('true' frogs) are reviewed with emphasis on their species diversity, host specificity and geographical distribution. New molecular data (nuclear lsrDNA and mitochondrial COI sequences) are presented for tapeworms of four species of ranid frogs in North America, including the poorly known Ophiotaenia saphena Osler, 1931 of Rana clamitans Latreille and R. catesbeiana (Shaw), which is redescribed using new material from Arkansas, USA. Tapeworms of R. sphenocephala (Cope) and R. pipiens Schreber, the latter previously identified as O. saphena, represent another, putative new species, but are not formally described due to insufficient available material. Proteocephalus papuensis Bursey, Goldberg et Kraus, 2008 from Sylvirana supragrisea (Menzies) is transferred to Ophiotaenia La Rue, 1911 as a new combination. After a critical review of the literature, only nine nominal species of Ophiotaenia are recognised as valid, which is in contrast to the large number of ranid frogs (> 440 spp.). The reasons for this striking disparity are briefly discussed, and a key based on morphology is presented for the identification of all species of Ophiotaenia from the Ranidae. Molecular data are available for only two taxa from North America that form a monophyletic group. The relationships among tapeworms of ranid frogs occurring in other zoogeographical regions are not yet known. The taxonomic status of Batrachotaenia Rudin, 1917, which was erected to accommodate proteocephalids from amphibians, is also discussed. To facilitate future studies, a tabulated summary of all 32 species of proteocephalids belonging to three genera reported from amphibians (frogs and salamanders) is presented, with information on their hosts, distribution, and taxonomically important characters, including key measurements.

Pseudomurraytrema fergusoni n. sp. is described from the Pealip Redhorse, Moxostoma pisolabrum from the Black River (White River drainage), Lawrence County, Arkansas, USA. This represents the second monogenean described from M. pisolabrum as well as the second species of Pseudomurraytrema reported from an Arkansas catostomid. The description includes partial 18S rRNA and 28S rRNA gene sequences (732 bp and 851 bp, respectively), helping fill a void in sequence data from North American monogeneans, particularly those in the genus Pseudomurraytrema. In addition, histopathologic changes associated with the infection resulted in severe localized pathologic lesions in gills of the host, suggesting compromise of respiratory surfaces within affected areas adjacent to the worms., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Little is known about the coccidian parasites of North American birds of the family Cardinalidae. A single isosporan, Isospora vanriperorum was previously described over 40 years ago from the northern cardinal, Cardinalis cardinalis from Hawaii. Since then, it was also reported in the green-winged saltator, Saltator similis from Brazil but the identification was invalidated recently. Feces were collected in July 2022 from two C. cardinalis found dead in Lamar County, Texas, USA. One sample contained oöcysts representing I. vanriperorum. Oöcysts are spheroidal to subspheroidal with a smooth uni-layered wall, measure (L × W) 23.8 × 22.4 µm and have a length/width (L/W) ratio of 1.04; a micropyle and oöcyst residuum are absent but polar granule(s) are present. Sporocysts are ovoidal and measure 15.5 × 10.5 µm, L/W 1.5; a knob-like Stieda body and a rounded sub-Stieda body are present. The sporocyst residuum is more often composed of various-sized granules dispersed between and across the sporozoites; it is less often in a compact rounded mass. This isosporan has now been reported from the northern cardinal for the second time but most importantly, from the mainland USA for the first time., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Purpose: Many passeriform birds are excellent hosts of coccidian parasites but little is known of the coccidians infecting members of the family Passerellidae, particularly from the dark-eyed junco, Junco hyemalis (Linnaeus, 1758). Here, we report from morphometric and mensural data a new species of Isospora from J. hyemalis in Arkansas, USA., Methods: During November 2020, seven adult J. hyemalis were taken with a mist net from Polk County, Arkansas, USA, and their faecal samples examined for coccidian parasites. Samples were placed in individual vials containing aqueous potassium dichromate. They were examined for coccidia after flotation in Sheather's sugar solution, measured, and photographed., Results: A single J. hyemalis (14%) was found to be passing a new species of Isospora. Oöcysts of Isospora pittmani n. sp. were spheroidal to subspheroidal with a smooth bi-layered wall, measured (L × W) 24.8 × 23.8 µm, and had a length/width (L/W) ratio of 1.04; a micropyle and oöcyst residuum was absent but typically one to up to four polar granule(s) was present. Sporocysts are ovoidal to ellipsoidal and measured 15.0 × 10.0 µm, L/W 1.5; a flattened Stieda body was present as well as a barely discernible sub-Stieda body but para-Stieda bodies were absent. The sporocyst residuum was composed of various-sized granules dispersed between and across the sporozoites. A spheroidal to ellipsoidal posterior refractile body and spheroidal anterior refractile body occasionally seen, but a nucleus was not observed. Only two previous isosporans have been reported from passerellid birds and the new species can readily be distinguished from them., Conclusion: This is the first coccidian reported from J. hyemalis and, more importantly, the first isosporan known from any member of the family Passerellidae in North America., (© 2022. The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Compared to other commonly examined passerine birds for coccidian (Apicomplexa) parasites, little is available on the coccidia of birds of the family Hirundinidae, including barn swallows (Hirundo rustica). Feces was collected in May 2022 from two nesting H. rustica in McCurtain County, Oklahoma, USA; the samples contained oöcysts representing a new species of Isospora. Oöcysts of Isospora zimmermani n. sp. are subspheroidal to ovoidal with a smooth bi-layered wall, measure (L × W) 22.8 × 20.8 µm, and have a length/width (L/W) ratio of 1.1; a micropyle and oöcyst residuum were absent but polar granule(s) are present. Sporocysts are ellipsoidal to ovoidal and measure 15.2 × 9.6 µm, L/W 1.6; a knob-like Stieda body and a rounded sub-Stieda body are present. The sporocyst residuum is composed of compact spheroid with a dense, irregular mass of finer granules lying between and dispersed among the sporozoites. The new species represents only the second isosporan reported from H. rustica but the first from the USA, and fourth species documented from the avian family Hirundinidae. This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:1F1E71C3-56E8-4EA7-A9B0-1E585FAA9DE0., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

The eastern mole, Scalopus aquaticus (L.), is a common inhabitant of loamy soils in Canada, the eastern United States, and Mexico. Seven coccidian parasites have been previously reported from S. aquaticus, including 3 cyclosporans and 4 eimerians from hosts taken in Arkansas and Texas. A single S. aquaticus, collected in February 2022 in central Arkansas, was found to be passing oocysts of 2 coccidians, a new species of Eimeria, and Cyclospora yatesiMcAllister, Motriuk-Smith, and Kerr, 2018. Oocysts of Eimeria brotheri n. sp. are ellipsoidal (sometimes ovoidal) with a smooth bilayered wall, measure 14.0 × 9.9 μm, and have a length/width (L/W) ratio of 1.5; both micropyle and oocyst residua are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 8.1 × 4.6 μm, L/W 1.8; a flattened to knoblike Stieda body as well as a rounded sub-Stieda body are present. The sporocyst residuum is composed of an irregular mass of large granules. Additional metrical and morphological information is provided on oocysts of C. yatesi. This study demonstrates that although several coccidians were previously documented from this host, additional S. aquaticus should be examined for coccidians from Arkansas as well as other parts of its range., (© American Society of Parasitologists 2023.)

Polystomatidae is a monogenean family whose representatives infect mainly (semi)-aquatic tetrapods. Species of Sphyranura Wright, 1879 exhibit ectoparasitism on salamander hosts, with molecular work supporting their inclusion within Polystomatidae, at an early diverging, yet unresolved, position in the clade of otherwise endoparasitic polystomatid parasites of batrachian hosts. Records of representatives of Sphyranura are scarce with genetic data only available for S. oligorchis Alvey, 1933. Based on detailed morphological examination and comparison with type material, we identified worms belonging to Sphyranura infecting Oklahoma salamander (Eurycea tynerensis) as S. euryceae Hughes & Moore, 1943. Along with an amended diagnosis of Sphyranura, we provide the first molecular data for S. euryceae in the form of a mitochondrial genome and nuclear (18S, 28S rRNA) markers. Close morphological similarity between the two species of Sphyranura is reflected in low genetic divergence. Mitochondrial level comparison reveals instances of tRNA gene rearrangements in polystomatids. Although the phylogenetic reconstruction supports Sphyranura as early branching in the lineage of polystomatid monogeneans infecting batrachians, certain nodes remain unresolved., (© S.J. Leeming et al., published by EDP Sciences, 2023.)

Between November 2018 and December 2021, 35 juvenile and adult Western Creek Chubsuckers, Erimyzon claviformis, were collected from 5 sites in western and southern Arkansas (Ouachita and Red River drainages), and their gills, gallbladders, fins, integument, other major organs, and musculature were examined for myxozoans. The fins of 12 (34%) individuals were infected with a novel species, Myxobolus stuartae n. sp. Qualitative and quantitative morphological data were obtained from formalin-fixed preserved myxospores. Molecular data from ethanol-preserved specimens consisted of a 2,028 base pair sequence of small subunit (SSU) ribosomal DNA (rDNA) from a specimen collected in Nevada County. Three other specimens from Polk County yielded partial SSU rDNA sequences that were identical to the first sequence. Phylogenetic analyses placed M. stuartae n. sp. as sister to Myxobolus bibullatus (Kudo, 1934), both clustering with other catostomid-infecting myxobolids. This is the first fin-infecting myxozoan reported from E. claviformis., (© American Society of Parasitologists 2022.)

During April 2016 and again in November 2021, four Chain Pickerels, Esox niger were collected from Union (n = 3) and Nevada (n = 1) counties, Arkansas, USA, and 65 Grass Pickerels, Esox americanus vermiculatus were collected between January 2015 and December 2021 from four counties of Arkansas (n = 31) and McCurtain County, Oklahoma, USA (n = 34), and examined for myxozoans. Gallbladders of an individual E. niger from Nevada County, Arkansas, as well as a single individual of E. a. vermiculatus from Sevier County, Arkansas, were infected with a new myxozoan, Myxidium whippsi n. sp. Qualitative and quantitative morphological data were from formalin-fixed preserved myxospores while molecular data (SSU rRNA gene) consisted of 2031bp (host: E. niger) and 1723 bp (host: E. a. vermiculatus) partial sequences of the small subunit ribosomal RNA gene. Phylogenetic analysis placed M. whippsi n. sp. in a clade with two other myxozoans, Zschokkella nova and Myxidium truttae, previously reported from cyprinids and salmonids, respectively. We document the first report of a myxozoan from E. a. vermiculatus. This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:A50FCEB3-68C3-428E-A04E-37A16790F1EB., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

During October and November 2021, 33 creek chubs, Semotilus atromaculatus, were collected from 3 sites in Polk County, Arkansas (Ouachita River drainage), and their gills, gallbladder, fins, integument, musculature, and other major organs were examined for myxozoans. The gills of 9 (27%) were infected with a new myxozoan, Myxobolus fountainae n. sp. Qualitative and quantitative morphological data were from fresh and formalin-fixed preserved spores, while molecular data consisted of a 1918 base pair sequence of the partial small subunit ribosomal RNA gene. Phylogenetic analysis grouped M. fountainae n. sp. with the other leuciscid-infecting myxobolids from North America and within a larger clade of European myxozoans. In addition, histological information is provided on the infection. A previous record of Myxobolus muelleriBütschli, 1882, from the gills and ureters of S. atromaculatus is considered invalid and represents an unknown species. Myxobolus fountainae n. sp. is the only named myxozoan known to infect the gill filaments of S. atromaculatus, whereas Myxobolus pendula (Guilford, 1967) infects the gill arches., (© American Society of Parasitologists 2022.)

Purpose: Nothing is known of the coccidian parasites of the Carolina wren, Thryothorus ludovicianus ludovicianus (Latham, 1790). Here, we report a new species of Isospora from T. l. ludovicianus from Oklahoma, USA., Methods: Faecal samples were collected between September and December 2021 from five adult T. l. ludovicianus taken with a mist net from McCurtain County, Oklahoma, USA, and examined for coccidian parasites. Samples were placed in individual vials containing aqueous potassium dichromate. They were examined for coccidia after flotation in Sheather's sugar solution, measured, and photographed. Tissue samples from the intestine of a single positive bird were removed and placed in 10% neutral-buffered formalin for examination of coccidian endogenous stages., Results: A single Carolina wren (20%) was found to be passing a new species of Isospora. Oocysts of Isospora edwardwilsoni n. sp. were subspheroidal to ovoidal with a smooth bi-layered wall, measured (L × W) 23.8 × 20.3 µm, and had a length/width (L/W) ratio of 1.2; a micropyle and oocyst residuum was absent but typically one to up to four polar granule(s) was present. Sporocysts are ovoidal to ellipsoidal and measured 15.3 × 9.7 µm, L/W 1.6; a knob-like Stieda body was present as well as a distinct rounded sub-Stieda body. The sporocyst residuum was composed of various-sized granules in a compact irregular mass or dispersed between and across the sporozoite, or a combination of both within the same sporocyst. Information is also presented on the endogenous development of this coccidian., Conclusion: This is the first coccidian reported from T. l. ludovicianus and, more importantly, the first known from the members of the family Troglodytidae in North America., (© 2022. The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Ochoterenatrema is a small genus of lecithodendriid digeneans that includes six species parasitic in Neotropical bats in North and South America. Members of this genus are characterized by the presence of a pseudogonotyl formed by thickened tegument on the left side of the ventral sucker. We examined morphology of specimens belonging to five species of Ochoterenatrema from Brazil, Ecuador and the USA and describe two new Ochoterenatrema spp. (Ochoterenatrema sphaerula n. sp. and Ochoterenatrema gracilis n. sp.). These new species are readily differentiated from their congeners by a combination of morphological characters, including the distribution of vitelline follicles and the body shape. We have provided the first DNA sequences for Ochoterenatrema. Newly generated partial nuclear 28S rDNA and mitochondrial cox1 gene sequences were used to differentiate among species and study the phylogenetic affinities of Ochoterenatrema spp., including one of the new species, O. gracilis n. sp., as well as Ochoterenatrema diminutum, Ochoterenatrema fraternum and Ochoterenatrema cf. labda. The phylogeny of the Microphalloidea based on 28S had well-supported topology, particularly at the family level. The Ochoterenatrema clade was strongly supported; however, the internal topology of the clade was weakly supported. Comparison of sequences revealed 0.4-1.3% interspecific divergence in 28S and 9.1-19.7% interspecific divergence in cox1 among Ochoterenatrema spp. We hypothesize that extremely diverse fauna of bats in South and Central America harbors multiple undescribed species of Ochoterenatrema. Several lecithodendriid genera from bats and other hosts are yet to be included in future molecular phylogenetic analyses to test the monophyly of this extremely diverse digenean family and analyze evolutionary affinities of its constituent taxa., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Isospora fitzpatricki n. sp. is described from a yellow warbler, Setophaga petechia (L.), from McCurtain County, Oklahoma, USA. Oöcysts of the new species are subspheroidal to ovoidal with a smooth bi-layered wall, measure (L × W) 24.2 × 20.4 μm, and have a length/width (L/W) ratio of 1.2; a micropyle and oöcyst residuum are both absent, but polar granule(s) are present. Sporocysts are ovoidal to ellipsoidal and measure 14.5 × 9.2 μm, L/W ratio of 1.6; a knob-like Stieda body is present as well as a distinct rounded sub-Stieda body. The sporocyst residuum is composed of various-sized granules in a compact rounded or irregular mass or dispersed between and across the sporozoite. The oöcysts of I. fitzpatricki n. sp. can be differentiated from five other congeners reported from members of the New World warbler family Parulidae from either Mexico, Costa Rica, or Brazil, by being larger on average as well as by possessing a prominent rounded sub-Stieda body, sporozoite striations, and an posterior refractile body. Information is also presented on an Isospora sp. being passed by S. petechia that we choose not to describe as a putative novel species of Isospora at this time. These two isosporans represent the first coccidians reported from S. petechia and, more importantly, the first known from the members of the Parulidae in the USA., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Author(s).)

The flat-headed snake, Tantilla gracilis Baird and Girard is a small reptile belonging to the family Colubridae. Feces from a single T. gracilis from McCurtain County, Oklahoma, USA, was collected and examined for coccidia; it was found to be passing a new species of Caryospora. Oöcysts of Caryospora sargentae n. sp. are spheroidal to typically subspheroidal with a moderately-pitted bi-layered wall, measure (L × W) 20.7 × 19.2 µm, and have a length/width (L/W) ratio of 1.1; a micropyle and oöcyst residuum were absent but one to several small, irregular to spheroidal masses of non-refractile debris within the oocyst was present as well as a polar granule attached to the inner oöcyst wall. Sporocysts are ovoidal and measure 15.0 × 11.0 µm, L/W 1.4; a nipple-like Stieda body is present as well as a distinct rounded sub-Stieda body. The sporocyst residuum is composed of a large, dense, irregular mass of various sized granules located between and often obscuring the sporozoites. This is the third coccidian described from the flat-headed snake. In addition, we include some data on the endogenous development of the coccidian., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

A new genus, Laruella n. gen., is proposed for the proteocephalid cestode L. perplexa (La Rue, 1911) n. comb. (syn. Proteocephalus perplexus La Rue, 1911), a parasite of a 'living fossil', the bowfin ( Amia calva ), in North America. The new genus is differentiated from other proteocephalid genera by having a massive four-lobed scolex without an apical organ and bearing suckers possessing tear-shaped sphincters on their inner rim, vitelline follicles forming L-shaped lateral fields, with the vitellarium turned inwards (medially) ventrally alongside the posterior margin of the ovary, a ring-like vaginal sphincter situated at a considerable distance from the genital atrium, and ellipsoid eggs resembling those of bothriocephalid and diphyllobothriid tapeworms, except for the absence of an operculum. Phylogenetic relationships of the new genus are not resolved, but it belongs to the so-called Neotropical clade of the Proteocephalidae, which is composed mainly of Neotropical tapeworms of siluriforms and other teleosts, but also Nearctic and Palaearctic species of Ophiotaenia La Rue, 1911 from snakes and amphibians. A morphologically similar species, Proteocephalus ambloplitis (Leidy, 1887) from bass ( Micropterus spp.) in North America, is provisionally retained in Proteocephalus Weinland, 1858 because its relationships to L. perplexa are not yet clear. The former species differs from L. perplexa by the presence of a large apical organ, large, elongate vaginal sphincter situated near the genital atrium, vitelline follicles limited to lateral longitudinal fields, strongly coiled vas deferens within the cirrus sac, and a convoluted vaginal canal anterior to the ovarian isthmus. Laruella perplexa reportedly has a s broad spectrum of hosts but most are likely postcyclic or accidental hosts. A list of cestode parasites reported from bowfin is provided; it includes eight species and three taxa not identified to the species level. However, only three adult cestodes, L. perplexa and two species of Haplobothrium Cooper, 1914, are typical tapeworm parasites of bowfin, but previous molecular studies indicate possible existence of a putative new species in bowfin., Competing Interests: There is no conflict of interest in the submitted manuscript entitled “A young parasite in an old fish host: A new genus for proteocephalid tapeworms (Cestoda) of bowfin (Amia calva) (Holostei: Amiiformes), and a revised list of its cestodes.”, (© 2022 The Authors.)

Fibricola and Neodiplostomum are diplostomid genera with very similar morphology that are currently separated based on their definitive hosts. Fibricola spp. are normally found in mammals, while Neodiplostomum spp. typically parasitize birds. Previously, no DNA sequence data was available for any member of Fibricola. We generated nuclear ribosomal and mtDNA sequences of Fibricola cratera (type-species), Fibricola lucidum and 6 species of Neodiplostomum. DNA sequences were used to examine phylogenetic interrelationships among Fibricola and Neodiplostomum and re-evaluate their systematics. Molecular phylogenies and morphological study suggest that Fibricola should be considered a junior synonym of Neodiplostomum. Therefore, we synonymize the two genera and transfer all members of Fibricola into Neodiplostomum. Specimens morphologically identified as Neodiplostomum cratera belonged to 3 distinct phylogenetic clades based on mitochondrial data. One of those clades also included sequences of specimens identified morphologically as Neodiplostomum lucidum. Further study is necessary to resolve the situation regarding the morphology of N. cratera. Our results demonstrated that some DNA sequences of N. americanum available in GenBank originate from misidentified Neodiplostomum banghami. Molecular phylogentic data revealed at least 2 independent host-switching events between avian and mammalian hosts in the evolutionary history of Neodiplostomum; however, the directionality of these host-switching events remains unclear.

Alaria , Didelphodiplostomum and Pharyngostomoides are among genera of diplostomid digeneans known to parasitize mammalian definitive hosts. Despite numerous recent molecular phylogenetic studies of diplostomids, limited DNA sequence data is available from diplostomids parasitic in mammals. Herein, we provide the first 28S rDNA and cox1 mtDNA sequences from morphologically identified, adult specimens of Didelphodiplostomum and Pharyngostomoides . Newly generated 28S sequences were used to infer the phylogenetic interrelationships of these two genera among other major lineages of diplostomoideans. The phylogeny based on 28S and a review of morphology clearly suggests that Pharyngostomoides should be considered a junior synonym of Alaria , while Didelphodiplostomum should be considered a junior synonym of Tylodelphys . Pharyngostomoides procyonis (type species), Pharyngostomoides adenocephala and Pharyngostomoides dasyuri were transferred into Alaria as Alaria procyonis comb. nov. , Alaria adenocephala comb. nov. and Alaria dasyuri comb. nov. ; Didelphodiplostomum variabile (type species) and Didelphodiplostomum nunezae were transferred into Tylodelphys as Tylodelphys variabilis comb. nov. and Tylodelphys nunezae comb. nov. In addition, Alaria ovalis comb. nov. (formerly included in Pharyngostomoides ) was restored and transferred into Alaria based on a morphological study of well-fixed, adult specimens and the comparison of cox1 DNA sequences among Alaria spp. The diplostomid genus Parallelorchis was restored based on review of morphology., (© The Author(s) 2022. Published by Oxford University Press on behalf of The Linnean Society of London. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

As part of a biannual health examination, coprological samples from 3-mo-old Central American river turtles, Dermatemys mawii (Gray, 1847) in a breeding program in Belize, Central America, revealed a previously undescribed coccidian (Apicomplexa) in 17 of 46 (37%) samples. Of 3 positive fecal samples transported to the University of Florida, coccidian oocysts were observed in 1 sample. Sporulated oocysts were measured and described, and using polymerase chain reaction (PCR), an approximately 400-base pair (bp) region of both the small subunit (18S) ribosomal RNA gene and 1,200-bp region of the internal transcribed spacer (ITS) gene were amplified in all 3 samples and their products were sequenced. For comparative value, the same PCR reactions and amplifications were performed on a fecal sample containing oocysts of Eimeria mitraria obtained from a red-eared slider, Trachemys scripta elegans. Results indicated a new eimerian in D. mawii, Eimeria grayi n. sp., (© American Society of Parasitologists 2022.)

The Carolina chickadee, Poecile carolinensis Audubon is a relatively small songbird belonging to the tit and chickadee family Paridae. Feces from three P. carolinensis from Polk County, Arkansas, USA, and a single P. carolinensis in McCurtain County, Oklahoma, USA, were collected and examined for coccidia; the latter bird was found to be passing a new species of Isospora. Oöcysts of Isospora oklahomaensis n. sp. are subspheroidal to ovoidal with a smooth to slightly-pitted bi-layered wall, measure (L × W) 32.1 × 28.3 µm, and have a length/width (L/W) ratio of 1.1; a micropyle and oöcyst residuum were absent but a bilobed and refractile polar granule is present. Sporocysts are ellipsoidal and measure 18.4 × 11.8 µm, L/W 1.6; a prominent Stieda body is present as well as a distinct sub-Stieda body. The sporocyst residuum is composed of an irregular mass of granules lying between and dispersed among the sporozoites. This is the first coccidian described from the Carolina chickadee and, most importantly, only the second described from a member of the Paridae, worldwide., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

Myxosporean species in the genus Cystodiscus are parasites of amphibians and have been reported from several continents. Typically used for the identification of myxozoans, the spores produced by these species are similar to one another, possessing 2 polar capsules and being ovoid. The number of transverse depressions on the spore can be useful for delineating species, but these can sometimes be difficult to distinguish. In North America, Cystodiscus serotinus and Cystodiscus melleni have been described, and for C. serotinus in particular, numerous reports and a wide range of hosts have been associated with this species. Given the challenges of identifying some of these species, we questioned whether all encounters of Cystodiscus species can be attributed to these 2 described species, or if there may be additional undescribed species or cryptic species. Over 7 yr, 383 amphibians representing 13 species of toads, frogs, and salamanders were collected from sites in Oklahoma and Arkansas. Cystodiscus infections were found in 56 individuals (14.6%). Tissues from these infected individuals were preserved in alcohol for genetic analysis. The small subunit (SSU) and large subunit (LSU) ribosomal RNA genes were partially sequenced and analyzed phylogenetically. Nine distinct SSU sequence types and 7 distinct LSU sequence types were identified. Phylogenetically, sequence types were attributable to C. serotinus, C. melleni, Cystodiscus axonis, and an undescribed species. For the previously described species, there were multiple SSU sequence types: 4 for C. serotinus and 2 for both C. melleni and C. axonis. Phylogenetic patterns were similar for the LSU sequence analysis using a shorter sequence than the SSU, and we propose that the LSU is useful for initial barcoding of Cystodiscus species in any future surveys. In our qualitative assessment of sequence types compared to geography and host species, SSU types C1 and C2 (C. axonis) were only found in Union County, Arkansas, and McCurtain County, Oklahoma, respectively. Also, salamanders were only infected with SSU types B or D (C. melleni), and type B was only found in salamanders. Our finding of C. axonis in North America is notable because this species was described in Australia and is associated with host pathology. Our work reveals that there are cryptic species of Cystodiscus in the United States, one of which may be a pathogen, highlighting the importance of genetic analysis for future surveys of these species., (© American Society of Parasitologists 2021.)

During 9-10 February 2018 and 21-22 February 2020, 7 adult Blue Suckers, Cycleptus elongatus, were collected by hoop nets from the Red River, Little River County (n = 3), and the Black River, Lawrence County (n = 4), Arkansas, and their gills, gallbladders, fins, integument, other major organs, and musculature were examined for myxozoans. All 7 (100%) were infected with an unknown species of gill-infecting Myxobolus sp. Twenty formalin-fixed plasmodia (cysts) of Myxobolus cloutmani n. sp. were elliptoidal, 407 μm long × 270 μm wide. Formalin-fixed myxospores were orbicular to broadly elliptoidal, 8.7 μm long × 7.8 μm wide. Two polar capsules were pyriform and subequal in size, extending over halfway in the myxospore. The larger polar capsule was 5.5 μm long × 3.1 μm wide, while the shorter was 5.1 × 2.9 μm. A coiled polar filament possessed 5 or 6 coils. The myxospore was 3.7 μm thick in sutural view, with a distinct sutural ridge. Qualitative and quantitative morphological data were from formalin-fixed as well as ethanol-preserved spores, while molecular data consisted of a 2,010 base pair sequence of the partial 18S ribosomal RNA gene and a 2,502 base pair sequence of the partial 28S ribosomal RNA gene. Phylogenetic analysis grouped M. cloutmani n. sp. with the other catostomid-infecting myxobolids. This is the first myxozoan reported from C. elongatus., (© American Society of Parasitologists 2021.)

Forty-nine olive-backed pocket mice, Perognathus fasciatus were collected during 2011 and 2012 from 4 sites in Wyoming and examined for coccidian parasites. Fifteen (31%) were found to be passing oocysts of a new species of Eimeria Schneider, 1875. Sporulated oocysts of Eimeria fasciata n. sp. are ellipsoidal to ovoidal, 23.3 × 20.7 (19-27 × 17-25) μm, with a shape index of 1.1; they typically contain a single, smooth, bubble-like oocyst residuum. Oocysts possess 1-2 polar granules, lack a micropyle, and are bilayered with a thickness of 1.3 μm. Sporocysts are ovoidal, 10.0 × 8.2 (8-12 × 7-10) μm, with a shape index of 1.2; they contain a sporocyst residuum that appears similar to a cluster of 1-8 grapes. The Stieda body is small, appearing flattened to knobby, and there are no subStieda or paraStieda bodies. This new eimerian represents the only coccidian, to date, reported from P. fasciatus, as well as the only species from any heteromyid rodent in Wyoming., (© American Society of Parasitologists 2021.)

Purpose: Nothing is known about the coccidian parasites of vagrant shrews, Sorex vagrans Baird, 1868. Here we report, for the first time, the occurrence of Eimeria longirostris Hertel and Duszynski, 1987 from faecal contents of S. vagrans from Montana, USA., Methods: Faecal samples, collected in July and August 2020 from six pitfall-trapped vagrant shrews as well as faeces from two masked shrews, Sorex cinereus Kerr, 1792, and one American pygmy shrew, Sorex hoyi Baird, 1857 from Missoula County, Montana, USA, were examined for coccidian parasites. Samples were placed in individual vials containing aqueous potassium dichromate. They were examined for coccidia after flotation in Sheather's sugar solution, measured, and photographed., Results: Three (50%) S. vagrans and one (50%) S. cinereus were found to be passing oocysts of Eimeria longirostris Hertel and Duszynski, 1987; the single S. hoyi was negative. Oocysts from S. vagrans were subspheroidal and measured (average L × W) 16.1 × 14.4 µm with an L/W ratio of 1.1. One (typically) to two polar granules was present but a micropyle and oocyst residuum were absent. Sporocysts were ovoidal and measured 9.6 × 6.2 µm with an L/W ratio of 1.6. A Stieda body was present but subStieda and paraStieda bodies were absent. The sporocyst residuum was composed of various sized granules typically scattered between and across the sporozoites but sometimes formed a loose aggregate or compact mass., Conclusion: We document a new host and new geographic record for E. longirostris from S. vagrans and report the coccidian from S. cinereus for the third time but the first report from specimens from Montana. This coccidian has now been reported from at least 12 species of shrews within the genus Sorex in 14 US states and two provinces in Canada.

Aim: The present work aims to morphologically and molecularly characterize an Eimeria sp. recovered from an adult, captive barred owl Strix varia in Mississippi, USA. While the owl was shedding oocysts, no clinical signs of coccidiosis were observed., Materials and Methods: Oocysts collected from a barred owl, S. varia were isolated from feces by fecal flotation and characterized by light microscopy. The oocysts were allowed to sporulate in K 2 Cr 2 O 7 for 7 days and measured for comparison with previously described Eimeria species. Genomic DNA was extracted from measured oocysts and the cytochrome c oxidase subunit 1 mitochondrial gene was amplified and sequenced for comparison and phylogenetic analyses with publicly available sequence data., Results: Oocysts collected from S. varia were morphologically and molecularly consistent with all previous accounts of Eimeria megabubonis from the great horned owl Bubo virginianus and morphologically consistent with the only account of Eimeria varia from S. varia. Phylogenetic analyses grouped the E. megabubonis sequence from the present study with previously reported sequences from E. megabubonis., Conclusion: Morphological and molecular data from oocysts collected in this study reveal S. varia is a host for E. megabubonis. Agreement between current data, morphological and molecular data of E. megabubonis, and morphological data from the original description of E. varia indicates E. varia is a junior synonym of E. megabubonis.

Urocleidus sayani n. sp. is described from the gills of pirate perch (Aphredoderus sayanus) in the Wisconsin backwaters of the upper Mississippi River and was found in samples from the Southeastern United States. Urocleidus sayani n. sp. is the second monogenean described from the pirate perch and the first for this host within Dactylogyridae. The description includes a partial 18S rRNA gene sequence (623 bp), filling a void in sequence data from North American monogeneans., (© American Society of Parasitologists 2021.)

The chigger, Euschoengastia pipistrelli Brennan, is a trombiculid mite that infests a variety of vespertilionid bats in North America. It has been reported from at least 9 species of bats from 18 U.S. states. However, nothing is available on the actual in situ infestation and ultrastructure of this chigger. Here we document some stereoscopic photographs of the infestation as well as a scanning electron micrograph of the mite from a common bat species. We also provide a summation of host and state records for this chigger., (© American Society of Parasitologists 2021.)

The summer tanager, Piranga rubra (L., 1758) is a medium-sized songbird formerly belonging to the tanager family Thraupidae but now has been placed within the family Cardinalidae. Nothing is known about the coccidian parasites of this stunningly colorful bird. Feces from 2 P. rubra found dead in McCurtain County, Oklahoma were collected and examined for coccidia; 1 was found to be passing a new species of Isospora. Oocysts of Isospora mccurtainensis n. sp. are subspheroidal to ovoidal with a smooth bilayered wall, measure (length × width [L × W]) 21.7 × 19.5 μm, and have a L/W ratio of 1.1; a micropyle and oocyst residuum were absent but a bilobed and refractile polar granule is present. Sporocysts are ellipsoidal and measure 13.9 × 8.6 μm, L/W 1.6; a knoblike Stieda body is present as well as a distinct sub-Stieda body. The sporocyst residuum is composed of a granular compact cluster with a dense, irregular mass of granules lying between and dispersed among the sporozoites. This is the first coccidian reported from P. rubra and, most important, only the first known from the Cardinalidae in the mainland of the United States., (© American Society of Parasitologists 2021.)

A new species of Acroeimeria Paperna & Landsberg, 1989 is described from the spotted house gecko, Gekko monarchus (Schlegel) from Peninsular Malaysia. Oöcysts of Acroeimeria grismeri n. sp. are spheroidal to subspheroidal with a smooth bi-layered wall, measure on average 18.4 × 17.3 µm, and have a length/width (L/W) ratio of 1.1; a micropyle and an oöcyst residuum are absent but variable polar granule(s) are present, commonly in Brownian movement. Sporocysts are ellipsoidal and measure on average 8.6 × 6.7 µm, L/W 1.3; Stieda, sub-Stieda and para-Stieda bodies are absent. The sporocyst residuum is composed of numerous spheroidal granules in the center of the sporocyst. This is the initial species of coccidian reported from G. monarchus and one of the few reported from any reptile from Peninsular Malaysia.

Ictalurid catfishes (Siluriformes) in North America harbor proteocephalid tapeworms of the subfamily Corallobothriinae. Type species of 2 of 3 genera of these tapeworms from ictalurids are redescribed, based on museum and newly collected material. Essexiella fimbriata (Essex, 1928) is typified mainly by a wide, umbrella-shaped scolex with a metascolex formed by numerous folds of tissue, anteriorly directed suckers without sphincters, vitellarium bent inwards posteriorly, "flower-shaped" uterus (with anterior, lateral, and posterior diverticula), and a conspicuously pre-equatorial genital atrium. Verified host records of this cestode are only from 3 species of Ictalurus Rafinesque, 1820. Megathylacoides giganteum (Essex, 1928), which seems to be specific to the channel catfish (Ictalurus punctatus), possesses a globular scolex, with a weakly developed metascolex formed by tissue folds posterior to the suckers, anterolaterally directed suckers with large semilunar sphincters, proglottids that are widest at the level of the genital atrium at the anterior third of the proglottid, and uterine diverticula that do not reach the vitelline follicles laterally. A new subfamily, Essexiellinae Scholz and Barčák, is proposed to accommodate species of EssexiellaScholz, de Chambrier, Mariaux and Kuchta, 2011 (type genus), MegathylacoidesJones, Kerley and Sneed, 1956, and CorallotaeniaFreze, 1965 from ictalurid catfishes in the Nearctic Region. These tapeworms possess a metascolex, medullary genital organs, uterus lined with numerous chromophilic cells, pre-equatorial genital atrium, and uterine development of type 2. The new subfamily was monophyletic in all molecular phylogenetic analyses, being most closely related to 3 Neotropical proteocephalids from the redtail catfish, Phractocephalus hemioliopterus (Bloch and Schneider, 1801), but distant from all remaining proteocephalid tapeworms from freshwater fishes in North America., (© American Society of Parasitologists 2020.)

Background: Myxidium kudoi Meglitsch, 1937 has been described from the type host, blue catfish Ictalurus furcatus, with no additional host records or molecular data available for this species., Purpose: To provide molecular data and a novel host locality for this species and carry out phylogenetic analyses to infer the evolutionary relationship of the species to other members of the family Myxidiidae for which DNA sequence data is available., Methods: These data were collected using myxospores from the gallbladder of a blue catfish, Ictalurus furcatus collected from Lake Texoma, Oklahoma, USA. Myxospores were morphologically consistent with the only other account of this species and not any other Myxidium species described from siluriform fishes., Results: Myxospores were oblong with rounded ends and were 10.8-12.6 (11.6 ± 0.5) µm in length and 4.7-6.6 (5.7 ± 0.5) µm in width. Polar capsules were subspherical and 2.7-3.9 (3.4 ± 0.3) µm in length and 2.4-3.5 (3.1 ± 0.3) µm in diameter, with each capsule containing a polar filament with 3-4 coils. Molecular data consisted of a 2918-bp sequence of the partial 18S, complete ITS1, 5.8S, ITS2, and partial 28S ribosomal rRNA regions as well as a 2455-bp sequence of partial 28S ribosomal RNA. The partial 18S and 28S data was used in a concatenated Bayesian phylogenetic analysis to further infer the evolutionary relationships of the Myxidiidae. Additionally, the partial 18S data was used in a separate phylogenetic analysis., Conclusions: The present work reports novel morphological and molecular data for Myxidium kudoi as well as a novel locality of occurrence for this species. In concatenated phylogenetic analysis using 18S and 28S data and other molecular data from Myxozoa, M. kudoi grouped with other freshwater Myxidiidae. In the single-locus, 18S analysis, M. kudoi grouped with Myxidium rhodei from Rutilus rutilus and Myxidium amazonense from Corydoras melini, the only other Myxidium species of catfish for which molecular data are available.

Introduction: North American woodrats or packrats (genus Neotoma) are excellent hosts of coccidians and several species remain to be reported as hosts. Eleven species of Eimeria have been previously described from Neotoma spp. However, it has been nearly 35 years, since the last eimerian (E. ladronensis Reduker and Duszynski, 1985) was described from any woodrat species., Methods: Six adult eastern woodrats, Neotoma floridana (Ord, 1818) were collected with Sherman live traps from Blue Haze Vista, Polk County, Arkansas, USA. Fecal specimens or rectal contents were examined for coccidia. Measurements were taken on 30 sporulated oöcysts and photographs were taken using brightfield optics., Results: One (17%) eastern woodrat was found to be passing oocysts of Eimeria machardyi n. sp. as well as three (50%) with Eimeria albigulae Levine, Ivens, and Kruidenier, 1957, and two (33%) with Eimeria glauceae Wheat and Ernst, 1974. We provide a description of a new species of Eimeria from eastern woodrats, Neotoma floridana, the first photomicrograph of E. glauceae, and additional information on E. albigulae. A summation of the eimerians of North American woodrats is also provided., Conclusions: Nine of 13 (69%) species of packrats north of México have now been reported to harbor 12 species of eimerians. Additional surveys of Neotoma spp. which have not yet been reported as hosts, particularly those from México and Central America, should yield more eimerians and distributional records as well as the possibility of discovery of new species.

New World flying squirrels, Glaucomys spp., are nocturnal arboreal sciurid rodents that have been previously surveyed for coccidial parasites. To date, 4 species of Eimeria have been reported from 2 species of Glaucomys. Here we report 2 species of eimerians from southern flying squirrels (Glaucomys volans) and the endemic Prince of Wales flying squirrel (Glaucomys sabrinus griseifrons). Oocysts of Eimeria dorneyi Levine and Ivens were found to be passing in the feces of 4 G. s. griseifrons from Alaska and a new species of Eimeria was present in feces from 6 G. volans from Arkansas. Oocysts of Eimeria hnidai n. sp. are ellipsoidal with a bilayered wall, measure 23.7 × 13.7 μm, and have a length/width (L/W) ratio of 1.7; a micropyle and oocyst residuum are absent but polar granule(s) are present. Sporocysts are ellipsoidal-elongate and measure 11.8 × 4.9 μm, L/W 2.2; Stieda body is present but sub-Stieda and para-Stieda bodies are absent. The sporocyst residuum is composed of small indistinct granules along the edge or in the center of the sporocyst. This is the first coccidian reported from G. volans from Arkansas as well as the initial coccidian (E. dorneyi) reported from G. s. griseifrons from Alaska. We also provide a summation of the coccidia known from North American flying squirrels., (© American Society of Parasitologists 2020.)

A revisionary study revealed two species of monogeneans, Dactylogyrus crucis Rogers, 1967 and Dactylogyrus lythruri sp. n., parasitising Lythrurus Jordan (formerly a subgenus of Notropis Rafinesque, 1818). New records and updated taxonomy of seven of 12 known minnows of the genus of Lythrurus are provided for D. crucis. A record of Dactylogyrus attenuatus Mizelle et Klucka, 1953 (syn. Dactylogyrus umbratilus [Kimpel, 1939], nomen nudum) on Lythrurus umbratilis (Girard) is referrable to D. crucis. Dactylogyrus lythruri is described from eight species of Lythrurus. It most closely resembles Dactylogyrus beckeri Cloutman, 1987, but is distinguished by having a smaller base of the male copulatory organ (MCO) and lacking a ventral enlargement of the distal end of the basal process. Previous reports of Dactylogyrus banghami Mizelle et Donahue, 1944 and Dactylogyrus cf. beckeri Cloutman, 1987 from Lythrurus atrapiculus (Snelson) and Lythrurus bellus (Hay) from Alabama, and Dactylogyrus confusus Mueller, 1938 from L. umbratilis in Illinois are herein relegated to D. lythruri. Four species of Lythrurus appeared not to be infected with Dactylogyrus.

The wood thrush, Hylocichla mustelina, is a North American passerine bird closely related to other thrushes and is widely distributed across North America. Nothing is known of the coccidian parasites of this bird. Feces from a single H. mustelina found dead in McCurtain County, Oklahoma were collected and examined for coccidia; it was found to be passing a new species of Isospora. Oocysts of Isospora gmelini n. sp. are subspheroidal to ellipsoidal with a smooth bilayered wall, measure (length [L] × width [W]) 19.5 × 16.5 μm, and have a L/W ratio of 1.2; a micropyle and oocyst residuum were absent but polar granule(s) are present. Sporocysts are ellipsoidal to elongate and measure 13.4 × 8.9 μm, L/W 1.5; a buttonlike Stieda body is present, but sub-Stieda and para-Stieda bodies are absent. The sporocyst residuum is composed of a compact spheroid with a dense, irregular mass of finer granules lying between and dispersed among the sporozoites. Although several isosporans have been reported from other turdid birds, mainly from Brazil and Costa Rica, this is the initial coccidian reported from H. mustelina and only the second known from the Turdidae in the mainland of the United States., (© American Society of Parasitologists 2020.)

A new species of Acroeimeria Paperna & Landsberg, 1989 is described from Wiegmann's torquate lizard Sceloporus torquatus torquatus Wiegmann from Toluca, México. Oöcysts of Acroeimeria wiegmanni n. sp. are sub-spheroidal with a smooth bi-layered wall, measure on average 28.6 × 23.6 µm, and have a length/width (L/W) ratio of 1.2; a micropyle and an oocyst residuum are absent but polar granule(s) are present. Sporocysts are ellipsoidal and measure on average 11.7 × 8.6 µm, L/W 1.3; Stieda, sub-Stieda and para-Stieda bodies are absent. The sporocyst residuum is composed of numerous spheroidal granules in the center of the sporocyst. Endogenous stages of the new species develop in the duodenum of hosts. This is the first species of coccidian reported from S. t. torquatus and one of the few reported from a reptile in México.

A new species of monogenean, Dactylogyrus pisolabrae n. sp., was found parasitizing the gills of the Pealip Redhorse, Moxostoma pisolabrum, from Oklahoma. Dactylogyrus pisolabrae is morphologically similar to Dactylogyrus apos, Dactylogyrus atripinnei, Dactylogyrus duquesnei, and Dactylogyrus niger, all parasitizing other species of suckers, by possessing a robust, sickle-shaped male copulatory organ, but differs from these and all other species of North American Dactylogyrus by possessing 2 unique wing-like projections opposite each other on the proximal portion of the accessory piece. Dactylogyrus pisolabrae represents the first monogenean reported from the Pealip Redhorse.

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

Although nine nominal species of Eimeria Schneider, 1875 have been reported from owls (Strigiformes Wagler), molecular data are available for only one, Eimeria megabubonis Upton, Campbell, Weigel & McKown, 1990. This species has been reported from the great horned owl, Bubo virginianus (Gmelin) at the type-locality of Kansas, USA, and the additional localities of Oklahoma and Mississippi, USA. Eimeria bubonis Cawthorn & Stockdale, 1981, also from B. virginianus, is represented in the literature only by its original description from Saskatchewan, Canada. The present work reports a novel host locality of E. bubonis from B. virginianus in Arkansas, USA. Additionally, novel molecular data from the 18S ribosomal RNA gene and the cytochrome c oxidase subunit 1 mitochondrial gene is provided for E. bubonis. Phylogenetic analysis using the newly generated and previously published sequence data for Eimeria spp. is also presented.