Scientific disagreements due to empirical problems—not enough data, not enough of the critical type of data, problems in analyzing the data—are generally short-lived and resolved in the next cycle of data production. Such disagreements are thus transitory in nature. Persistent scientific conflicts, on the other hand, do not necessarily mean some facts are correct and some are wrong, nor do they mean that we do not have enough information. More often, such persistent conflicts mean that the conceptual frameworks used by different groups of researchers are insufficient to resolve apparent conflicts in the data. The latter seems to be the case with persistent disagreements about the phenomenon of cospeciation, wherein there has historically been no framework that allows us to understand speciation by host switching when the host and parasite lineages involved are of equal ages. This situation can now be resolved with the emergence of what has become known as the “Stockholm Paradigm.” In short, re-examination of what has been dubbed the “classic case of cospeciation” shows that divergent views of cospeciation are subsumed and reconciled within the larger explanatory framework of the Stockholm Paradigm. The implications are considerable, given the need to have a fundamental understanding of faunal structure, assembly, and distribution in addition to an understanding of the historical and evolutionary drivers of diversity within the current arena of accelerating environmental change, ecological perturbation, and emerging infectious diseases.

A total of 1,021 freshwater mussels (Bivalvia: Unionidae) representing 12 species collected from 23 rivers between May 2002 and September 2006 in Manitoba, Saskatchewan, and North Dakota, U.S.A. were examined for aspidobothrean parasites. Nine of the 12 species were infected with aspidobothrean parasites. Anodontoides ferussacianus, Lasmigona complanata, Lasmigona compressa were uninfected. Aspidogaster conchicola was recovered from 77 individuals representing 6 of 12 mussel species. Prevalence as high as 100% was recorded for Amblema plicata and Potamilus alatus. The highest infection intensity was 254 observed in P. alatus. Cotylogaster occidentalis was recovered from 91 individuals representing 8 of 12 mussel species. Prevalence was typically lower by comparison with A. conchicola, although samples of single infected Fusconaia flava, Lampsilis siliquoidea, and Strophitus undulatus resulted in 100% prevalence in some localities. Cotylogaster occidentalis infection intensity was also much lower with the highest being 10 from Lampsilis cardium. This represents the first report of A. conchicola and C. occidentalis from Manitoba and North Dakota. Aspidogaster conchicola is reported for the first time from Lampsilis cardium. Cotylogaster occidentalis is reported for the first time from the mussels Amblema plicata, Fusconaia flava, Lampsilis cardium, Potamilus alatus, Quadrula quadrula, and Strophitus undulatus. Aspidogaster conchicola was not found infecting some mussel species that had been previously reported as parasitized hosts, perhaps suggesting local host specificity.

Four Japanese species of Plestiodon (Reptilia: Scincidae, formerly Eumeces): Plestiodon japonicus, Plestiodon finitimus, Plestiodon latiscutatus, and Plestiodon oshimensis oshimensis collected from Honshu, Shikoku, and Kyushu of the Japanese main islands and Amamioshima Island of the Ryukyus, Japan, were examined to make a more exact list of the parasitic nematodes and to reveal their distribution patterns. Six nematode species were found, including 2 species of Heterakidae (Meteterakis japonica and Meteterakis amamiensis), 1 species of Rhabdiasidae (Kurilonema markovi), 1 species of Trichostrongylidae (Oswaldocruzia socialis), 1 species of Cosmocercidae (Cosmocercidae gen. sp.), and 1 species of Pharyngodonidae (Pharyngodonidae gen. sp.). Six new hosts were recorded and 19 new localities were reported. Meteterakis amamiensis and K. markovi were distributed on both sides of Watase's line, which is known as a geographical distribution boundary between the Oriental and Palaearctic regions in Japan. A parapatric distribution of M. japonica and M. amamiensis in the Japanese main islands and coexistence of K. markovi and Neoentomelas asatoi in Amamioshima Island were revealed.

Here we provide a new record of Riggia acuticaudata parasitizing the armored catfish, Ancistrus sp., from the Paraguay River basin, Brazil. On May and July 2010, 27/47 (57.4%) specimens of Ancistrus sp. collected in 2 streams at Corguinho municipality in the state of Mato Grosso do Sul, were found to be parasitized by R. acuticaudata. This is the second time R. acuticaudata has been reported parasitizing Ancistrus sp. from the Paraguay River basin. In addition, it represents an important record for the known distribution of this isopod species, which was previously known only from the type locality. We also provide information on the reproductive biology of this isopod species.

Ten species of acanthocephalans are known from 30 species of fish in Lake Baikal. Three species in the family Echinorhynchidae were studied and reported: (1) Echinorhynchus salmonis Müller, 1784 ( =  Metechinorhynchus salmonis (Müller 1784) Petrochenko, 1956), previously designated as Echinorhynchus salmonis baicalensis Bogolepova, 1957 (actually Dogiel and Bogolepova, 1957) that we consider invalid. Echinorhynchus s. baicalensis was studied from whitefish Coregonus lavaretus (Linnaeus, 1758) (Family Salmonidae) in Chivyrkui Bay and from Kessler's (sand) sculpin Leocottus kesslerii (Dybowski, 1874) (Family Cottocomephoridae) at Goryachinsk on the eastern shore of Lake Baikal in Pribaikalsk District, Republic of Buryatia. Our scanning electron microscopy observations demonstrate miniapical proboscis hooks, hooks with dorsal indentation, 2 anteroventral trunk bumps, and variable position of male and female gonopores, for the first time. (2) Echinorhynchus cinctulus (Porta, 1905) Amin, 2013 ( = Pseudoechinorhynchus borealis (von Linstow, 1901) Petrochenko, 1956) was studied from burbot, Lota lota (Linnaeus, 1758) (Family Lotidae) in Chivyrkui Bay and Khankh. The thorny hooks, inconsistencies in proboscis armature, hook size, dermal micropores, and position of male and female gonopores are reported. (3) Echinorhynchus truttae Schrank, 1788 ( =  Metechinorhynchus truttae (Schrank, 1788) Petrochenko, 1956) was studied from L. kesslerii in Goryachinsk. Features of the proboscis, hooks, female gonopore, dermal micropores, and eggs are presented.

One hundred thirty skinks representing 7 species of Sphenomorphus (Scincidae) from Papua New Guinea were examined for helminths: S. aruensis, S. cinereus, S. fragilis, S. nigriventris, S. pratti, S. maindroni, S. simus. Two species of Cestoda (Oochoristica javaensis, Ophiotaenia greeri), 1 species of Digenea (Saurokoilophilia kinsellai), and 13 species of Nematoda (gravid individuals of Abbreviata oligopapillata, Aplectana macintoshii, Aplectana novaeguineae, Cosmocerca zugi, Entomelas moraveci n. sp., Falcaustra papuensis, Meteterakis crombiei, Moaciria moraveci, Oswaldocruzia bakeri, Parapharyngodon maplestoni, Pseudorictularia disparilis, and larvae of both Abbreviata sp. and Riculariidae gen. sp.) were found. The new nematode species was described and 19 new host records are reported. Helminths of 17 species of Sphenomorphus from New Guinea Island are reviewed; 59% of identified helminth species were found to be endemic. Mean helminth species diversity per species of Sphenomorphus for the 17 species so far studied was 6.4 ± 0.9 SE (range 2–14).

Neoechinorhynchus dimorphospinus Amin and Sey, 1996, was described from 4 species of marine fishes in the Arabian Gulf off Kuwait. Specimens of N. dimorphospinus have been reported only twice since then from marine and freshwater fishes also from the Arabian Gulf and brackish waters associated with it. The 2 latter reports offered no new descriptive accounts. SEM studies based on recent collections of N. dimorphospinus from Klunzinger's mullets, Liza klunzingeri (Day, 1888) (Mugiliformes) (new host record), revealed many new features that were not possible to include in the original description using optical microscopy. These new features include an apical organ in the proboscis, a broad prominent collar at the anterior end of the trunk, prominent longitudinal grooves on proboscis hooks, a pair of sensory structures in the neck, the subterminal position of the female gonopore with a minute lipless vulva, micropores on the trunk not showing differentiation in various trunk regions, and eggs in different stages of development. There is extensive damage to the host intestine due to invading specimens of N. dimorphospinus. Worms destroy the epithelial lining of L. klunzingeri and migrate through the thin smooth muscle wall of the intestine into the host body cavity. Extensive host hemorrhaging, tissue necrosis, villi compression, and loss of host epithelial cells appears to be the typical pathology in intestinal sites occupied by this worm.

From 2009 to 2012 collaborators of the Mongolian Vertebrate Parasite Project funded by the U.S. National Science Foundation mounted 4 major expeditions into south and southwestern Mongolia covering low- and high-altitude habitats consisting of desert, desert-steppe, and montane biomes. Both ecto- and endo-parasites were obtained from all of the approximately 4,000 mammals collected during this work. The present report contains a summary of the coccidian parasites of gerbils (Meriones Illiger 1811) collected during the warm-weather months in the Gobi and Altai regions of Mongolia. A total of 171 gerbils of 3 species from 22 separate localities were examined for coccidia. Coccidian oocysts were identified from 21 gerbils, but those found in one of those gerbils were probably pseudoparasites of the host from which they were recovered. From the remaining 20 gerbils, 7 morphotypes of Eimeria and 1 morphotype of Isospora Schneider 1881 were identified. Four of the 7 morphotypes of Eimeria were attributed to new species, which are described herein. In order to identify any apparent epidemiological trends, χ² tests were performed to identify correlations between infection with species of Eimeria or Isospora and host species, sex, infection with helminths, and year and month of capture. The only significant (α  =  0.10) correlation found using a χ² test was that between host species and infection by Eimeria spp. (P  =  0.07); oocysts of Eimeria spp.

Gigantolaelaps scolomys Gettinger and Gardner n. sp., an ectoparasitic mite (Acari: Laelapidae) associated with the rodent Scolomys melanops in Amazonian forests of Peru, is described and illustrated.

Coyotes (Canis latrans) are widely distributed in North America and were first recorded in Nova Scotia, Canada, in 1977. Although coyotes are host to a number of parasitic helminths, the parasite fauna of coyotes from Nova Scotia has not been previously investigated. The objectives of this study were to determine geographical range, prevalence, mean intensity, and abundance of metastrongyloid helminth parasites of the pulmonary system (Crenosoma vulpis, Oslerus osleri) in coyotes from Nova Scotia and to investigate whether prevalence, mean intensity, and abundance were consistent among different age classes of this mammal. In addition, hearts and pulmonary arteries were examined for the presence of Angiostrongylus vasorum (French heartworm) and Dirofilaria immitis (heartworm) to determine whether these heartworms had spread to Nova Scotia. A total of 235 coyotes were collected from trappers in the 2010–2011 season. Heart and lungs were removed from coyotes and examined for parasites by gross examination and lungflush. Canine teeth from lower jaws were removed to assess the age class of each coyote. Crenosoma vulpis and O. osleri were found in 31% and 37% of coyotes, respectively. There was a mean intensity of 8.8 adult C. vulpis and 9.5 nodules of O. osleri in infected coyotes across all age classes, with a tendency toward higher worm burdens in juvenile animals; significant differences were observed only for C. vulpis. There was a mean abundance of 2.7 adult C. vulpis and 3.5 nodules of O. osleri in coyotes sampled across all age classes, with significantly higher numbers of each species of worm in juveniles. Dirofilaria immitis and A. vasorum were not detected. The life history implications of these findings are discussed in relation to the possibility of parasite transmission to domestic dogs.

Seven species of endemic freshwater fish, Aphanius anatoliae, Aphanius villwocki (Cyprinodontidae), Capoeta angorae, Capoeta erhani, Capoeta mauricii, Chondrostoma fahirae, and Pseudophoxinus fahrettini (Cyprinidae) from Turkey were examined for acanthocephalans. Acanthocephalus sp., Neoechinorhynchus zabensis, Pomphorhynchus spindletruncatus, and Paralongicollum nurtenae n. sp. were found. The new species can be distinguished from its congeners by a suite of characters including the shape of the proboscis, which has an armature of 16–22 rows of 10–13 hooks, the posterior most circle of hooks alternating. All are new host and locality records. The geographic distributions of N. zabensis and P. spindletruncatus in Turkey may be due in part to changes in glacial river system connections that have occurred since the Pleistocene.

Fecal samples from 38 individually recognized vervet monkeys (Chlorocebus aethiops) from Loskop Dam Nature Reserve, South Africa, were examined for helminths. Analysis of 272 fecal samples revealed that all individuals were infected. Eggs of 5 helminth species were recovered. Prevalence of infection for Trichuris sp. was 92%, Oesophagostomum sp. was 84%, an indeterminate hookworm was 71%, an indeterminate spirurid was 68%, and Strongyloides sp. was 24%. Social group membership, age, and sex were not predictors of infection with any of the parasites detected. Monthly prevalence of parasites was not significantly correlated with mean monthly precipitation, minimum temperature, or maximum temperature, although some variables were correlated. Monthly prevalence of Oesophagostomum sp. was positively correlated with mean monthly minimum temperature (r  =  0.7152, n  =  12, P  =  0.013), mean monthly maximum temperature (r  =  0.6012, n  =  12, P  =  0.050), and mean monthly precipitation (r  =  0.6216, n  =  12, P  =  0.041). Monthly prevalence of Strongyloides sp. was positively correlated with mean monthly precipitation (r  =  0.7005, n  =  12, P  =  0.016). These are the first data on the parasitic infections of wild C. aethiops in Mpumalanga province of South Africa.

The freshwater fish parasite Leptorhynchoides thecatus contains several cryptic species that vary morphologically, molecularly, and in host use. This study investigated 404 individual fish for the presence of Leptorhynchoides, representing 24 species of fish from Otsego Lake, a glacially formed lake in New York, U.S.A. Of the 24 fish species represented, 12 species were infected with adult Leptorhynchoides in the digestive tract, including 4 species that were infected with gravid female worms: largemouth bass (Micropterus salmoides), smallmouth bass (Micropterus dolomieu), rock bass (Ambloplites rupestris), and redbreast sunfish (Lepomis auritus). Individuals from 5 fish species were infected with both adult worms in the digestive tract and with cystacanths in the body cavity. Measurements taken from specimens of the trunks, proboscides, and hooks, along with genetic sequences obtained from specimens at the mitochondrial gene cytochrome oxidase I (Cox1), suggest that the specimens encountered here are the “large form” of L. thecatus. Our survey data provide evidence of the importance of fish as paratenic hosts in the life cycle of L. thecatus and illustrate host use patterns somewhat different than previously reported for members of the L. thecatus species complex. This is the first study, to our knowledge, of a Leptorhynchoides species from the Mid-Atlantic drainage in which morphological, molecular, and ecological data are presented.

Serpentirhabdias dubielzigi n. sp. is described from Python regius from 2 separate locales in the United States. Many nematodes were observed in the eye, mouth, and subcutaneous tissues of 3 clinically affected, captive-bred, and captive-reared ball pythons. Although intact adult nematodes were not available for examination from the 2 Wisconsin, U.S.A., snakes, nematodes seen in histological sections from these cases and from the single Virginia, U.S.A., case were identical. The new species is described based on morphological characters of adult specimens obtained from formalin-fixed material from the Virginia case, and nematodes in histological sections from all cases. The designation is further supported by phylogenetic analysis of the nematodal internal transcribed spacer (ITS) 1 region of ribosomal DNA (rDNA) obtained from an affected Wisconsin snake. The nematodes involved in these infections are distinct from currently described species of Serpentirhabdias in the family of the host parasitized, the sites of infection, the possession of double lateral alae and very long excretory glands on adult nematodes, the possession of single lateral alae on larvae in eggs, and a unique genetic sequence of the ITS1 region of rDNA as compared with currently reported sequences in GenBank.

The action of a water extract of Eysenhardtia polystachya on the cattle tick Rhipicephalus (Boophilus) microplus adults and larvae was studied. A stock solution of the extract was serially diluted in distilled, sterile water to obtain test concentrations of 1%, 0.5%, 0.25%, 0.125%, and 0.0625%, and a field trial was carried out on Cebu/Holstein F1 cattle experimentally infected with ticks. The extract was applied by spraying at a rate of 5 liters per animal per day for 7 d. The effectiveness of treatment against engorged females was assessed by measuring mortality and egg production in an adult immersion test. Although the natural extract was found to be nonlethal to adults, it had a significant effect on egg-laying at the highest concentrations, inhibiting 64.58% of oviposition. Using a larval immersion test, the extract was determined to be highly toxic to the larvae at the higher concentrations, killing 100, 99.94 ± 0.06, 99.35 ± 0.37, 99.17 ± 0.14, and 99.03 ± 0.01 at concentrations of 1%, 0.5%, 0.25%, 0.125%, and 0.0625%, respectively, after 72 hr of immersion. Field trial results also revealed nonadulticidal efficacy. Nevertheless, adult ticks and egg masses recovered from treated calves weighed less than those collected from untreated controls. Also, daily application of the plant extract over 7 d provided 94.82% control as measured by the index of fecundity in engorged females. Aqueous extract from E. polystachya possesses a well-defined acaricidal effect on R. microplus larvae and inhibits oviposition. These findings allow us to suggest that further extraction and characterization of the active compound(s) responsible for the observed acaricidal activity may reveal new xenobiotics for further drug-development and can contribute to our understanding of the larvacidal mechanism of action of E. polystachya extract.

Trachemys dorbigni, the Brazilian slider turtle, occurs in the southernmost portion of South America in Brazil, Uruguay, and Argentina. Despite being an abundant species in southern Brazil, its helminth fauna is little known. In this context, 60 turtles from southern Brazil were examined for helminths. The nematodes Spiroxys contortus (Gnathostomatidae) and Falcaustra affinis (Kathlaniidae) were found, both representing new host records. This is the southernmost locality reported for Falcaustra affinis, as the previous known extent of its southern distribution was in Mexico.

Between June 2012 and July 2013, 43 slender madtoms (Noturus exilis) and 21 Black River madtoms (Noturus maydeni) were collected from 4 counties of northern Arkansas and examined for helminths. Eleven (26%) slender madtoms were infected with digenean trematodes, including 3 (7%) with metacercaria of Posthodiplostomum minimum, 3 (7%) with Alloglossidium sp., and 7 (16%) with Plagioporus sp.; a single (5%) Black River madtom was infected with Caecincola sp. We document new host records for each of these 4 helminths. Notable among these new host records are new distributional records for Caecincola sp. To our knowledge this represents the first report of any helminth from N. exilis and N. maydeni.

Here we present the occurrence of Pyelosomum cochlear Looss 1899 in the urinary bladder of an olive ridley sea turtle Lepidochelys olivacea (Eschscholtz, 1829) from Brazil. This parasite species has previously been reported only from Chelonia mydas from Egypt, the United States (including Puerto Rico), Panama, and Costa Rica. This paper reports the first occurrence of P. cochlear parasitizing L. olivacea and the first occurrence of this parasite in the western South Atlantic.

Oocysts of a coccidium found in the small intestine of a road-killed opossum, Didelphis marsupialis (Didelphimorphia: Didelphidae), are described and identified as Eimeria marmosopos. Sporulated oocysts (n  =  57) were subspherical to spherical and measured 21.9 × 22.1 (20–25 × 20–25); oocyst wall rough and striated, yellowish and bilayered; micropyle, polar body, and oocyst residuum all absent, but some oocysts have a polar granule. Sporocysts were ovoidal, 9.8 × 8.7 (8–13 × 7–12), with both a conspicuous Stieda body and sub-Stieda body, but para-Stieda body was absent. The sporocyst residuum was composed of 2–5 globules (1–4 wide) and several smaller ones. Sporozoites (n  =  10) were comma-shaped, ~7 × 2.7 and had 1 refractile body at their wider end and a centrally located nucleus. These morphological characters were compared with other Eimeria species found in related genera of New World marsupials; based on oocyst morphology, we identified this species as Eimeria marmosopos Heckscher, Wickesberg, Duszynski, and Gardner 1999. This finding constitutes both a new host genus and new geographical record for this species.

Between May 2012 and July 2013, 4 eastern hognose snakes (Heterodon platirhinos) were collected from Arkansas (n  =  2) and Oklahoma (n  =  2), U.S.A., and examined for coccidians. Feces from a single H. platirhinos from Arkansas, U.S.A., were found to be contain oocysts of Caryospora lampropeltis Anderson, Duszynski, and Marquardt, 1968. Oocysts obtained from host feces were spheroidal to slightly subspheroidal with a rough, colorless, and bilayered wall, measure 23.5 × 22.8 µm, and with a length/width (L/W) ratio of 1.0; both micropyle and oocyst residuum were absent, but a prominent polar granule was present. Sporocysts were ovoidal, 16.8 × 12.8 µm, L/W of 1.3; a prominent Stieda and sub-Stieda body was present; a sporocyst residuum was present and composed of numerous spheroidal granules dispersed into small and large granules. Sporozoites lie lengthwise and parallel in a semispiral in the sporocyst; a spheroidal anterior refractile and a posterior refractile body are present; a single nucleus is located between the 2 refractile bodies. To our knowledge, this represents the first report of a caryosporan reported from H. platirhinos as well as the only known coccidian from this host. A summary of hosts of C. lampropeltis is provided.

This note reports the first occurrence of Monticellius indicum Mehra, 1939, in the heart of the Hawksbill turtle, Eretmochelys imbricata Linnaeus, 1766, in the state of Espírito Santo, Brazil. This parasite has only previously been reported, to our knowledge, in Chelonia mydas from India, Brazil, and Costa Rica.

Twenty-nine hylid frogs, Nyctimystes perimetri, from Milne Bay Province, Papua New Guinea, were examined for helminths. Four species of Nematoda were found: Maxvachonia adamsoni, Maxvachonia ingens, Pseudorictularia disparilis, and encysted larvae of Abbreviata sp. Larvae of Abbreviata sp. were the most abundant (n  =  47) and had the highest prevalence (51%). Like many other Papua New Guinean hylids, N. perimetri is infected by a combination of Papuan ( =  New Guinea) endemics, Australian–Papuan endemics, and semicosmopolitan helminths.