GENETIC ANALYSIS OF ANCIENT CLONORCHIS SINENSIS EGGS ATTAINED FROM GORYEONG MUMMY OF JOSEON DYNASTY PERIOD.

Although Clonorchis sinensis is a parasite that still infects many people in East Asia, its genetics remain largely unknown. We conducted ancient DNA analysis of C. sinensis eggs obtained from a Joseon period mummy newly discovered in South Korea. Clonorchis sinensis DNA was amplified for internal transcribed spacer 1, cytochrome c oxidase subunit 1, and NADH dehydrogenase subunit 2 and 5 genes. The results of BLAST/NCBI showed that the consensus sequences were 98.24 to 100% identical to the modern and ancient C. sinensis sequences reported from Korea, China, Japan, and other Asian countries. Our report helps to fill in the genetic profile of ancient C. sinensis strains that infected East Asian people hundreds of years ago.

An unknown species of Leucochloridium (Trematoda: Leucochloridiidae) from northern Honshu, Japan.

Pulsating broodsacs of Leucochloridium sp. (Trematoda: Leucochloridiidae) were found from amber snails (Succinea lauta) in Iwate, the northern part of Honshu, Japan. A pattern with red-brown vertical stripes was characteristic of the broodsac. Very similar broodsacs were already detected from Okinawa Islands, the southern archipelago of Japan, and tentatively identified as Leucochloridium cf. passeri. A phylogenetic analysis based on DNA sequences of mitochondrial cytochrome c oxidase subunit 1 (cox1) showed that Leucochloridium sp. is different at species level from L. cf. passeri and that both species are related to Leucochloridium vogtianum from Europe. In this study the definitive identification of larval Leucochloridium sp. was impossible, but the resulting phylogeny confirmed that at least 4 species of Leucochloridium are distributed in Japan, depending on locality and climate. The DNA barcode generated in this study will be useful in detecting the adult stage of Leucochloridium sp. from birds.

Molecular Identification of the Human Pathogen Amphimerus sp. in the Freshwater Snail Aroapyrgus sp. in Ecuador.

Here, we report for the first time the snail intermediate host for the Amphimerus liver fluke, a foodborne trematodiasis. In Ecuador, Amphimerus of the Opisthorchiidae family, infects humans, cats, and dogs, in the tropical Pacific-coast region. Opisthorchiidae comprising also Clonorchis sinensis, Opisthorchis sp., and Metorchis sp., have complex life cycles involving a definitive and two intermediate hosts. We identified morphologically and investigated the presence and prevalence of Amphimerus cercaria and DNA in freshwater snails collected in a human-amphimeriasis endemic region in Ecuador, extracted DNA from snail tissue and emerged cercariae, performed real-time polymerase chain reaction (PCR) with the newly developed primers and probe amplifying the Amphimerus ribosomal internal transcribed spacer 2 (ITS2) region, and sequenced the amplified DNA fragment. We collected 2,800 snails, characterized four species Aroapyrgus sp., Melanoides tuberculata, Biomphalaria cousini, and Aplexa marmorata, isolated three cercariae morphotypes. Of the 640 snails analyzed by qPCR, only Aroapyrgus and one of the three cercariae resulted positive, at a 15% infection prevalence. Polymerase chain reaction revealed that the Aroapyrgus snail and cercaria-morphotype-3 corresponded to Amphimerus, but not to C. sinensis, Fasciola hepatica, or Paragonimus mexicanus. The sequence of amplified DNA product matched that of human-isolated Amphimerus. This finding constitutes the first documentation that Aroapyrgus sp. is the first intermediate host for the Amphimerus sp. that infect humans in Ecuador. The ITS2-gene PCR and sequencing analysis demonstrated a high prevalence of snail infection and proved useful for detecting the infection in snails, which findings can help the establishment of suitable control programs against transmission in any endemic region of interest.

Ocular Dirofilariasis Case in Thailand Confirmed by Molecular Analysis to Be Caused by Dirofilaria immitis.

A rare ocular dirofilariasis case along with the clinical characteristics, treatment, and outcome is reported. A whitish roundworm (10.6 cm long and 0.5 mm width) emerged from the pterygium, a triangular tissue growth on the cornea of the eye, of a male patient. The worm had a rounded anterior part, mouth without lips, smooth cuticular surface, and short rounded posterior tail with spicules: these features suggested that it was a male Dirofilaria sp. Molecular identification confirmed that the worm belonged to Dirofilaria immitis. This is the first molecular confirmation that D. immitis is a causative agent of ocular dirofilariasis in Thailand: dirofilariasis is a newly emerging zoonotic disease. Physicians should be alert to zoonotic filarial worms and knowledgeable about treatment of this disease.

MOLECULAR IDENTIFICATION OF JUVENILE NEOECHINORHYNCHUS SPP. (PHYLUM: ACANTHOCEPHALA) INFECTING OSTRACOD AND SNAIL HOSTS PROVIDES INSIGHT INTO ACANTHOCEPHALAN HOST USE.

The role of invertebrates in some acanthocephalan life cycles is unclear because juvenile acanthocephalans are difficult to identify to species using morphology. Most reports suggest acanthocephalans from turtle definitive hosts use ostracods as intermediate hosts and snails as paratenic hosts. However, laboratory studies of the life cycle suggest that ostracods and snails are both required hosts in the life cycle. To elucidate the role of ostracods and snails in acanthocephalan life cycles better, we collected 558 freshwater snails of 2 species, including Planorbella cf. Planorbella trivolvis and Physa acuta, from 23 wetlands in Oklahoma, U.S.A., and examined them for acanthocephalan infections. Additionally, we examined 37,208 ostracods of 4 species, Physocypria sp. (morphotype 1), Cypridopsis sp., Stenocypris sp., and Physocypria sp. (morphotype 2) for juvenile acanthocephalans from 2 wetlands in Oklahoma. Juvenile acanthocephalans were morphologically characterized, and the complete internal transcribed spacer (ITS) region of nuclear rDNA was sequenced from acanthocephalans infecting 11 ostracod and 13 snail hosts. We also sampled 10 red-eared slider turtles, Trachemys scripta elegans, and 1 common map turtle, Graptemys geographica, collected from Oklahoma, Arkansas, and Texas and recovered 1,854 adult acanthocephalans of 4 species. The ITS of 17 adult acanthocephalans of 4 species from turtle hosts were sequenced and compared to juvenile acanthocephalan sequences from ostracod and snail hosts from this study and GenBank to determine conspecificity. Of the 23 locations sampled for snails, 7 (30%) were positive for juvenile acanthocephalans in the genus Neoechinorhynchus. The overall prevalence and mean intensity of acanthocephalans in Planorbella cf. P. trivolvis and P. acuta were 20% and 2 (1-6) and 2% and 1 (1), respectively. In contrast, only 1 of 4 species of ostracods, Physocypria sp. (morphotype 1), was infected with larval/juvenile Neoechinorhynchus spp. with an overall prevalence of 0.1% and a mean intensity of 1 (1-2). Although 4 species of acanthocephalans infected turtle definitive hosts, including Neoechinorhynchus chrysemydis, Neoechinorhynchus emydis, Neoechinorhynchus emyditoides, and Neoechinorhynchus pseudemydis, all the ITS sequences from cystacanths infecting snail hosts were conspecific with N. emydis. In contrast, the ITS sequences from larval/juvenile acanthocephalans from ostracods were conspecific with 2 species of acanthocephalans from turtles (N. emydis and N. pseudemydis) and 1 species of acanthocephalan from fish (Neoechinorhynchus cylindratus). These results indicate that N. emydis infects freshwater snails, whereas other species of Neoechinorhynchus appear not to infect snail hosts. We document new ostracod and snail hosts for Neoechinorhynchus species, including the first report of an ostracod host for N. pseudemydis, and we provide novel molecular barcodes that can be used to determine larva, juvenile, and adult conspecificity of Neoechinorhynchus species.

DESCRIPTION AND PHYLOGENETIC AFFINITIES OF A NEW SPECIES OF NEOPSILOTREMA (DIGENEA: PSILOSTOMIDAE) FROM LESSER SCAUP, AYTHYA AFFINIS (ANSERIFORMES: ANATIDAE).

Neopsilotrema is a small genus of psilostomid digeneans parasitic in the intestine of birds in the Palearctic and Nearctic. At present, the genus includes 4 species: Neopsilotrema lisitsynae from the Palearctic and Neopsilotrema affine, Neopsilotrema lakotae, and Neopsilotrema marilae from the Nearctic. Herein, we describe a new species, Neopsilotrema itascae n. sp., from lesser scaup Aythya affinis collected in Minnesota. The species can be distinguished from congeners on the basis of the ventral sucker:oral sucker width ratio, body width:length ratio, and cirrus sac size, along with other characters. We generated new 28S ribosomal deoxyribonucleic acid (DNA) and NADH dehydrogenase (ND1) mitochondrial DNA sequence data of a variety of psilostomids from the Palearctic and Nearctic along with sequences of the ribosomal internal transcribed spacer (ITS) region (ITS1 + 5.8S + ITS2) from 3 Neopsilotrema species. The molecular phylogenetic affinities of a variety of psilostomid taxa were studied using 28S sequence data. The 28S sequences of psilostomids demonstrated 1-7.9% intergeneric divergence, whereas the sequences of ND1 had 17.7-34.1% intergeneric divergence. The interspecific divergence among members of Neopsilotrema was somewhat lower (0.2-0.5% in 28S; 0.3-0.4% in ITS; 12-15.7% in ND1). Our comparison of DNA sequences along with morphologic study suggests Holarctic distribution of N. lisitsynae.

First report of marine horsehair worms (Nematomorpha: Nectonema) parasitic in isopod crustaceans.

Nectonema, the only horsehair worm (Nematomorpha) genus found in marine environments, was previously known to be parasitic only in decapod crustaceans. We report Nectonema sp. as the first record of a marine nematomorph parasitic in isopod crustaceans. This is also the third record of marine nematomorphs from the North Pacific. Six infected isopods (Natatolana japonensis) collected from 1425 m of depth in the Sea of Japan each contained one to seven (mean 2.33) nematomorphs in the body cavity in the pereon. There was no correlation between the host body length and number of parasites. For Nectonema sp., we describe and illustrate morphological features of the parasitic juvenile stage and present nucleotide sequences for the cytochrome c oxidase subunit I gene (COI or cox1; 451 nt), 18S rRNA gene (1777 nt), and region spanning the internal transcribed spacer 1 (ITS1) and the 28S rRNA gene including the 5.8S rRNA gene and ITS2 (1218 nt in total). In an 18S maximum-likelihood tree that included 24 nematomorph species, Nectonema sp. grouped with N. agile from the northwestern Atlantic; the 18S gene from these two taxa was divergent by 11.8% K2P distance, suggesting that they are different species. Nectonema species may have a broader range of host groups than previously suspected, but may have been previously misidentified as nematode parasites.

REDESCRIPTION OF CATHARIOTREMA SELACHII (MACCALLUM, 1916) JOHNSTON AND TIEGS, 1922 (MONOGENOIDEA: MONOCOTYLIDAE), EMENDATION OF MONOTYPIC CATHARIOTREMA JOHNSTON AND TIEGS, 1922, AND PROPOSAL OF CATHARIOTREMATINAE N. SUBFAM. BASED ON MORPHOLOGICAL AND NUCLEOTIDE EVIDENCE.

We herein redescribe the enigmatic Cathariotrema selachii (MacCallum, 1916) Johnston and Tiegs, 1922 based on the holotype, paratypes, and newly collected specimens infecting the olfactory organ of 5 shark species from the Gulf of Mexico (all new host records): scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834) (Carcharhiniformes: Sphyrnidae); great hammerhead shark, Sphyrna mokarran (Rüppell, 1837); blacktip shark, Carcharhinus limbatus (Müller and Henle, 1839) (Carcharhiniformes: Carcharhinidae); spinner shark, Carcharhinus brevipinna (Müller and Henle, 1839); and Atlantic sharpnose shark, Rhizoprionodon terraenovae (Richardson, 1836) (Carcharhinidae). These specimens were morphologically indistinguishable from each other and from MacCallum's holotype and paratypes. Those sequenced had identical first internal transcribed spacer (ITS1) and large subunit ribosomal DNA (28S) nucleotide sequences. As such, C. selachii infects sharks of 2 orders (Carcharhiniformes, Lamniformes) and 3 families (Carcharhinidae, Sphyrnidae, Lamnidae) in the Northwestern Atlantic Ocean (type locality) and Gulf of Mexico (new records herein). This report is the first of new specimens of C. selachii in the Atlantic Ocean Basin in 95 yr and corrects long-standing error cascades and ambiguities concerning the morphology and systematic placement of C. selachii. Considering morphology and nucleotide-based phylogenetic evidence (28S, Bayesian analysis), we herein emend monotypic CathariotremaJohnston and Tiegs, 1922 and propose Cathariotrematinae Bullard n. subfam. for it and 4 other genera (all formerly assigned to Merizocotylinae Johnston and Tiegs, 1922). These genera comprise species infecting only the nose of sharks (monotypic Cathariotrema, SqualotremaKearn and Green, 1983 and SeptitremaKheddam, Chisholm, and Tazerouti, 2020 plus 3 species of TriloculotremaKearn, 1993) and nose of a chimaera (monotypic HolocephalocotyleDerouiche, Neifar, Gey, Justine, and Tazerouti, 2019). Cathariotrematinae differs from Merizocotylinae by having a 3-part attachment organ and by lacking open loculi that symmetrically encircle a cluster of >2 loculi in the center of the haptor. Monophyletic Cathariotrematinae (with sequences representing species of Cathariotrema, Triloculotrema, and Holocephalocotyle only) was sister to monophyletic Merizocotylinae, which together were sister to monophyletic Calicotylinae Monticelli, 1903. These subfamilies comprise a monophyletic group of monocotylids that have a double vagina and infect extrabranchial, enclosed niches (urogenital system, body cavity, olfactory chamber/nose) on their shark, ray, and chimaera hosts (all other monocotylids have a single vagina and infect the gill or body surfaces of rays only). Monocotylinae Taschenberg, 1879 and Decacotylinae Chisholm, Wheeler, and Beverley-Burton, 1995 were recovered as monophyletic. Heterocotylinae Chisholm, Wheeler, and Beverley-Burton, 1995 remained paraphyletic. We accept ParacalicotyleSzidat, 1970.

Morphological and Molecular Data Reveal Two New Species of Viannaia (Nematoda: Viannaiidae), Parasitizing Opossums (Mammalia: Didelphidae) in Mexico.

Two new species of Viannaia from the intestine of the North American opossums, Didelphis virginiana (Virginia opossum), and Philander opossum (gray four-eyed opossum), are described based on morphological and molecular data, through an integrative taxonomic approach. Maximum likelihood and Bayesian inference analyses for each dataset and the concatenated dataset were performed using a mitochondrial cytochrome c oxidase subunit 1 (COI) gene, and the nuclear ribosomal internal transcribed spacer region (ITS1-5.8S-ITS2). The phylogenetic analyses revealed 2 new species that occur in Mexico, one from the western state of Colima and another from the southern state of Chiapas. Our phylogenetic trees for both molecular markers and concatenated datasets yielded similar topologies with high bootstrap values and posterior probabilities. Viannaia is recovered as a monophyletic group, but the family Viannaiidae appears as non-monophyletic, due to the position of Travassostrongylus scheibelorum, similar to previous studies. Finally, the morphology of Viannaia and Hoineffia is discussed.

Evaluating DNA damage response through immunofluorescence staining of primordial germ cells in Caenorhabditis elegans L1 larva.

C. elegans L1 larvae have two well-defined primordial germ cells embedded in a niche comprising two somatic gonad precursor cells. Thus, C. elegans provides an ideal model for studying intercellular signaling in response to DNA damage. However, existing staining protocols are focused on worms in later developmental stages and are not optimized for the L1 larvae. Here, we present a revised protocol for assessing the DNA damage response utilizing immunofluorescence staining specifically in C. elegans L1 larva. For complete details on the use and execution of this protocol, please refer to Ou et al. (2019).

Helminth communities of endemic cyprinoids of the Apennine Peninsula, with remarks on ectoparasitic monogeneans, and a description of four new Dactylogyrus Diesing, 1850 species.

The fauna of the Apennine Peninsula is, in comparison to other southern European peninsulas, relatively species-poor regarding the number of endemic cyprinoid species. Nonetheless, the recent introduction of non-native species has significantly increased the total number of freshwater species in this region. Such invasive species may represent a threat to the native fauna, associated among other things with the introduction of non-native parasites with their original hosts.In the present study, we investigated endemic cyprinoid species for the presence of helminth parasites. A total of 36 ectoparasitic monogenean species and five endoparasitic helminth species were collected from ten cyprinoid species in five localities in northern Italy. Out of 20 Dactylogyrus species (gill monogeneans specific to cyprinoids), four were identified as new to science and herein described: Dactylogyrus opertus n. sp. and Dactylogyrus sagittarius n. sp. from Telestes muticellus, Dactylogyrus conchatus n. sp. from T. muticellus and Protochondrostoma genei, and Dactylogyrus globulatus n. sp. from Chondrostoma soetta. All new Dactylogyrus species appear to be endemic to the Apennine Peninsula; however, they share a common evolutionary history with the endemic Dactylogyrus parasitizing cyprinoids of the Balkans. This common origin of cyprinoid-specific parasites supports a historical connection between these two (currently separated) geographical regions.

Molecular characterization of Cysticercus tenuicollis isolates from sheep in the Nile Delta, Egypt and a review on Taenia hydatigena infections worldwide.

The predator­prey-transmitted cestode Taenia hydatigena infects a wide range of definitive and intermediate hosts all over the world. Domestic and sylvatic cycles of transmission are considered as well. The parasite has considerable economic importance, particularly in sheep. Here, the molecular characters of T. hydatigena cysticerci in sheep from the Nile Delta, Egypt were investigated for the first time. For this purpose, 200 sheep carcasses and their offal were inspected at the municipal abattoir, Dakahlia governorate, Egypt. Cysticerci of T. hydatigena were collected and molecularly characterized employing the mitochondrial 12S rRNA gene. Cysticerci were found in 42 (21%) sheep, mostly attached to the omenti, mesenteries and livers. After molecular confirmation, nine isolates were sequenced displaying six different haplotypes. Analysis of the T. hydatigena 12S rRNA nucleotide sequences deposited in GenBank revealed 55 haplotypes out of 69 isolates, displaying high haplotype (0.797) and low nucleotide (0.00739) diversities. For the Tajima D neutrality index, a negative value (−2.702) was determined, indicating the population expansion of the parasite. Additionally, global data summarized in this study should be useful to set up effective control strategies against this ubiquitous parasite.

GENETIC AND MORPHOLOGIC CHARACTERIZATION OF DIASCHISTORCHIS PANDUS (DIGENEA: PRONOCEPHALIDAE) TREMATODES EXTRACTED FROM HAWKSBILL TURTLES, ERETMOCHELYS IMBRICATA (TESTUDINES: CHELONIIDAE), IN GRENADA, WEST INDIES.

The hawksbill turtle Eretmochelys imbricata is a critically endangered species with a worldwide distribution. Limited information is available about the naturally occurring intestinal parasites of this species and what impact these parasites may have on the health of the hawksbill turtle. Diaschistorchis pandus was identified postmortem in 5 hawksbill turtles from Grenada, West Indies, using morphologic characterization. Sanger sequencing was performed for conserved ribosomal regions (5.8S, ITS2, 28S) and the mitochondrial cytochrome c oxidase subunit 1 gene (COI). Phylogenetic analysis of the 28S rRNA gene sequence data shows D. pandus clustering with other trematodes in the family Pronocephalidae, corroborating morphological classification. No genetic sequences have been previously reported for this trematode species, which has limited the collection of objective epidemiological data about this parasite of marine turtles.

Description and Molecular Differentiation of a New Skrjabinoptera (Nematode: Physalopteridae) from Eutropis macularia (Sauria: Scincidae) in North-Central Vietnam.

Skrjabinoptera vietnamensis n. sp. is described from specimens recovered from the stomach of Eutropis macularia in north-central Vietnam. The new species is characterized by the medium-sized male worms (6.7-8.7 mm in length and 154-182 µm in width) relative to known members of the genus, 2 pointed spicules of unequal length (87-112 µm and 56-72 µm in length), and 10 pairs of caudal papillae. Female worms are larger than male worms (10.7-18.4 mm in length and 264-411 µm in width), with the vulva situated in the anterior part, and embryonated, elliptical eggs, 35-46 µm long by 20-24 µm wide. Skrjabinoptera vietnamensis n. sp. represents the ninth species assigned to the genus and the first species recorded from the Oriental region. Partial sequences of the 18S ribosomal RNA gene (rDNA), and cytochrome c oxidase subunit 1 (COI) are provided for the new species. The molecular phylogenetic position of the genus Skrjabinoptera is briefly discussed.

A Review of the Parasite Fauna of the Black-Bellied Pangolin, Phataginus tetradactyla LIN. (Manidae), From Central Africa with the Description of Intraproboscis sanghae n. gen., n. sp. (Acanthocephala: Gigantorhynchidae).

A new archiacanthocephalan in the family Gigantorhynchidae, Intraproboscis sanghae n. gen., n. sp. is described from females collected from the African black-bellied pangolin Phataginus tetradactyla Linn. (Manidae) in the Central African Republic. A dichotomous key to the genera of Gigantorhynchidae is provided. The specimens presented are distinct from those of the genus Gigantorhynchus Hamann, 1892 that have only 1 or 2 circles of hooks (crowns) at the apical end of the proboscis and are found in South American mammals, except for Gigantorhynchus pesteri Tadros, 1966 from baboons in Rhodesia (Zimbabwe), Africa (Amin, 2013). They superficially resemble those of the other gigantorhynchid genus Mediorhynchus Van Cleave, 1916, especially in the organization of the truncate-cone proboscis and the position of the receptacle. Species of Mediorhynchus are bird parasites. The new genus, Intraproboscis, now the third genus in Gigantorhynchidae; however, is distinguished from Mediorhynchus by having a simple proboscis receptacle that is completely suspended within the proboscis, the passage of the retractor muscles through the receptacle into the body cavity posteriorly, absence of neck, and presence of a parareceptacle structure (first finding in the Archiacanthocephala) and a uterine vesicle; among other features, including the differential dorsoventral thickness of the body wall. The receptacle in Mediorhynchus is complex, with many accessory muscles and retractor muscles passing into the body cavity dorsally and ventrally. Our specimens reached 180 mm in length and the proboscis had 34-36 rows of 6-7 ventrally lamellated, rooted hooks each anteriorly, and 15-17 spinelike hooks each posteriorly. Micropores extended into the anterior and posterior proboscis and energy dispersive x-ray analysis (EDXA) of anterior hooks showed high levels of calcium and phosphorus but negligible traces of sulfur. Spinelike hooks in the posterior proboscis had lower levels of Ca and P and slightly higher levels of S. Molecular and phylogenetic analyses based on the 18S rDNA gene placed I. sanghae in a clade with the archiacanthocephalans Mediorhynchus, Moniliformis, Macracanthorhynchus, Oncicola, and Oligacanthorhynchus.

Description and Molecular Differentiation of a New Falcaustra (Nematode: Kathlaniidae) from the Indochinese Water Dragon, Physignathus cocincinus (Squamata: Agamidae) in North-central Vietnam.

Falcaustra vietnamensis n. sp. is described from the small intestine of Physignathus cocincinus from north-central Vietnam. The new species is characterized by the large male worms (20.2-28.8 mm in length and 557-724 µm in width) relative to known members of the genus, 2 sharply pointed alate spicules of equal length (1,128-1,256 µm in length), gubernaculum including 2 separate pieces, 1 ventral with a pointed distal end and 1 dorsal with a blunt distal end (164-192 µm and 155-172 µm in length, respectively), and 12 pairs of caudal papillae. Female worms are larger than male worms (24.2-34.1 mm in length and 532-735 µm in width), with the vulva situated in the posterior half of body, and elliptical eggs, 60-70 µm long by 42-47 µm wide. Falcaustra vietnamensis n. sp. represents the 38th species assigned to the genus and the third species recorded from a lizard host in the Oriental biogeographical region. Partial sequences of the 18S ribosomal RNA gene (rDNA), internal transcribed spacer regions (ITS), and cytochrome c oxidase subunit 1 (COI) are provided for the new species. The molecular phylogenetic position of the genus Falcaustra is briefly discussed.

A new molecular nomenclature for Taenia hydatigena: mitochondrial DNA sequences reveal sufficient diversity suggesting the assignment of major haplotype divisions.

Cysticercosis caused by the metacestode larval stage of Taenia hydatigena formerly referred to as Cysticercus tenuicollis is a disease of veterinary importance that constitutes a significant threat to livestock production worldwide, especially in endemic regions due to condemnation of visceral organs and mortality rate of infected young animals. While the genetic diversity among parasites is found to be potentially useful in many areas of research including molecular diagnostics, epidemiology and control, that of T. hydatigena across the globe remains poorly understood. In this study, analysis of the mitochondrial DNA (mtDNA) of adult worms and larval stages of T. hydatigena isolated from dogs, sheep and a wild boar in China showed that the population structure consists of two major haplogroups with very high nucleotide substitutions involving synonymous and non-synonymous changes. Compared with other cestodes such as Echinococcus spp., the genetic variation observed between the haplogroups is sufficient for the assignment of major haplotype or genotype division as both groups showed a total of 166 point-mutation differences between the 12 mitochondrial protein-coding gene sequences. Preliminary analysis of a nuclear protein-coding gene (pepck) did not reveal any peculiar changes between both groups which suggests that these variants may only differ in their mitochondrial makeup.

Molecular Phylogeny of Thelastomatoidea (Nematoda) with the Description of a New Genus and Two New Species of Hystrignathidae Associated with Bess Beetles (Coleoptera: Passalidae) from Oaxaca, Mexico.

Bess beetles (Passalidae) display important roles in forestall ecosystems, particularly in energy extraction from dead wood. These organisms maintain complex biological interactions with their gut symbiotic communities, including bacteria, protists, and metazoans. Very little is known about symbionts since most of the species of Passalidae haven't been studied from a parasitological point of view. Here we describe a new genus and 2 new species of nematodes of the family Hystrignathidae associated with 2 beetle species of the tribe Proculini collected in the State of Oaxaca, Mexico. Tuhmai garciaprietoi n. gen., n. sp., found in Vindex agnoscendus is characterized by the presence of an unarmed cervical cuticle, a subcylindrical procorpus and a conspicuous isthmus, a monodelphic-prodelphic reproductive system, and a short subulate tail. Urbanonema osorioi n. sp., found in Verres hageni mainly differs from other species of Urbanonema by the number and disposition of cervical spines, as well as by a subulate tail. For each new taxon, we describe the external and internal morphology, and we generated molecular data (nuclear ribosomal DNA) to place the new taxa in a phylogenetic context.

Batracholandros salamandrae (Oxyuroidea: Pharyngodonidae) in Endemic Salamanders (Amphibia: Plethodontidae) of the Trans-Mexican Volcanic Belt: Host Range Wide Distribution or Cryptic Species Complex?

Salamanders of the tribe Bolitoglossini Hallowell are a highly diversified group of amphibians, and their helminth parasite fauna has been scarcely studied. Some species of plethodontid salamanders distributed along the Trans-Mexican Volcanic Belt, in central Mexico, were sampled, and their helminth parasites were recovered for taxonomic identification. Specimens of a pharyngodonid nematode from 2 species of bolitoglossines of the genus Pseudoeurycea Taylor were morphologically identified as Batracholandros salamandrae (Schad, 1960) Petter and Quentin, 1976. These specimens were studied in further detail through light and scanning electron microscopy and were sequenced for 2 ribosomal genes and 1 mitochondrial gene to test the hypothesis of whether B. salamandrae is a species widely distributed in salamanders across the Nearctic biogeographic region, or if it represents a cryptic species complex. Our molecular results revealed that these specimens consisted of 2 genetic lineages in concordance with host species, although with slight morphological differences among specimens in each of them. A thorough study, including the generation of molecular data from individuals from other areas of North America, and the examination of type specimens, is required to test the reliability of these morphological differences and to corroborate the species identity of the 2 genetic lineages.

A New Species of Gordionus (Nematomorpha: Gordiida) from the Rocky Mountains of New Mexico.

The 19 genera within the phylum Nematomorpha contain approximately 350 species. The cosmopolitan genus Gordionus Müller, 1926 contains about 58 species, 6 of which occur in the contiguous United States of America. Recently, 2 new Gordionus species were described from high-altitude streams within the southern Rocky Mountains, near Santa Fe, New Mexico. Here we describe another new Gordionus species, from a high-altitude stream in the southern Rocky Mountains, from near Taos, New Mexico. The sites consisted of temporary puddles and a small human-made stream at 3,175-3,250-m altitude in aspen/pine woodland. Gordionus lokeri n. sp. has 1 areole type, which varies in shape and size between and within body regions. Midbody areoles are elongated, polygonal, or triangular, shingled, with the raised side of the areole serrated. The interareolar space is narrow, containing few bristles. The male cloacal opening is surrounded inside and outside by narrow branching bristles that bifurcate or trifurcate deeply; the furcae then subdivide several times terminally. Adhesive warts are lacking. Genetic data, consisting of partial cytochrome c oxidase subunit I (COI) gene sequences, clearly separated G. lokeri n. sp. from other Nearctic species. This is the third Gordionus species described from high-elevation streams in the Rocky Mountains. It appears that this high-altitude habitat represents the preferential niche for numerous species of this genus, and thus future work should focus on describing gordiid diversity in other parts of the Rocky Mountains.