Changes to the environment can have a profound effect on parasite transmission, and many examples have been documented. Although such studies describe the changes that occur, they do not usually address the question of whether or not the environmental effects are reversible. Both manmade and natural perturbations can alter habitats, leading to either an increase or decrease in parasite transmission. Two different categories of manmade environmental changes, with examples and whether they can be reversed, are discussed. The first type is where habitats are intentionally altered to improve human well-being but produce unintended consequences to parasite transmission. The examples described include the Aswan High Dam, the Diama Dam, urbanization, and family ranching. The second type is where commercial interests intentionally alter habitats for profit or to avoid expensive treatment of waste products, which then changes parasite transmission. The examples discussed are commercial logging, salmon farming, and water pollution from pulp and paper mills. In some cases, government intervention has mitigated the effects on parasite transmission although the habitat remains altered (e.g., Aswan High Dam). In another example, once the habitat was returned to its normal state, parasite transmission diminished (family ranching). However, there are environmental perturbations that are not easily reversed, such as urbanization and those caused by commercial endeavors. In these cases, improvements to the economy, public advocacy, and special interest groups may reduce the problem of increased parasite transmission, although they will not likely be completely mitigated.

Oligacanthorhynchus (Rudolphi, 1819) Schmidt, 1972 (Oligacanthorhynchidae) is a typical parasite of opossums (Didelphidae). This species of acanthocephalan exhibits a wide distributional range that extends from Brazil to as far north as the United States, but no data on the genetic divergence of this helminth has been provided thus far along its entire geographic range. The facts that O. microcephalus shows a relatively wide geographic range in Mexico and that it has been recorded in 3 species of opossum allowed us to conduct a molecular prospecting study to assess the genetic divergence among individuals and populations as well as to detect potentially exclusive lineages indicative of the presence of a species complex. In total, 81 specimens identified as O. microcephalus were collected from the intestines of 3 species of opossum in 8 localities across central and southeastern Mexico. The DNA sequences of 2 genes were generated; cytochrome c oxidase subunit 1 (cox 1) of the mitochondrial DNA and the domains D2 and D3 from large subunit of the nuclear ribosomal RNA (LSU). Maximum parsimony, maximum likelihood, and Bayesian inference analyses were performed for each dataset alone and for the combined datasets (LSU cox 1). All the phylogenetic analyses yielded 3 major clades with high bootstrap and posterior probability support values and with relatively high genetic divergence levels for both markers. However, the morphological study of specimens through both light and scanning electron microscopy, as well as the morphometric data, indicate that those specimens allocated into Clade I are smaller than those contained in Clades II and III. Lower genetic divergence values, as well as no clear-cut morphometric differences, indicate that Clades II and III are likely not independent lineages. Our results show at least 2 genetic lineages that may represent independent species, but we refrain at the moment on describing a new species in the lack of evidence gathered from a wider geographic range.

A survey of 2 species of ictalurid catfishes, channel catfish (Ictalurus punctatus) and yellow bullhead (Ameiurus natalis), was conducted in southeastern Texas, United States. Sixty-nine channel catfish and 26 yellow bullhead were collected from 6 sites within the Big Thicket National Preserve and 6 sites in surrounding bodies of water. Thirty-one species of parasites were found including 11 trematodes, 8 nematodes, 5 copepods, 3 cestodes, and 1 each of an acanthocephalan, leech, monogene, and myxozoan. Channel catfish harbored 23 species of parasites, yellow bullhead harbored 17, and 9 species occurred in both host species. Adult endohelminths dominated the fauna (18 species). Trematodes (Alloglossidium corti, Alloglossidium kenti, Polylekithum catahoulensis), a cestode (Megathylacoides giganteum), a nematode (Dichelyne robusta), and an ectoparasitic copepod (Ergasilus cerastes) constituted over 75% of the total parasite abundance. Although this constitutes the highest species diversity reported among similar surveys of catfishes in North America, much of the high species density is due to the presence of generalists, e.g., species of Spinitectus and Crepidostomum, more-commonly known to parasitize fishes of other groups.

During a dietary study of the naked goby, Gobiosoma bosc, collected from Charleston Harbor, South Carolina, in 2011–2012, gut content analyses showed the presence of several digenean species. The identity of one of the digenean species was investigated using molecular and morphological techniques. A comparison of 374 base pairs of an internal transcribed spacer region of ribosomal DNA (ITS2) with the GenBank database revealed that the digenean was a Homalometron sp., most likely Homalometron palmeri or an undescribed sister taxon. Specimens examined for morphology were immature, less than 1 mm in length, and had an oral to ventral sucker width ratio of 1:1.15–1.29. This is the first record of Homalometron sp. parasitizing a Gobiosoma bosc host, and it represents the first potential occurrence of H. palmeri outside of the Gulf of Mexico.

The presence of nematodes was investigated in 84 small mammals belonging to 10 species living in arid wild habitats from Central Tunisia. Hosts were infected with a total of 7 species of nematodes. The dominant parasite species was Gongylonema neoplasticum, which was found in the stomach of 7 host species with prevalences varying from 15.4% in Gerbillus campestris to 50% in Meriones shawi. Several nematodes, such as Syphacia obvelata, Acanthocheilonema viteae, Trichuris gerbilli, and G. neoplasticum, are potential zoonotic parasites. These latter species were collected from M. shawi, Meriones libycus, Mus musculus, Mus spretus, Rattus rattus, G. campestris, Psammomys obesus, and Ctenodactylus goundi, raising concern that these rodents and their associated rodent-borne helminths could be of potential concern for public health in this region.

Hoplorhynchus aster n. sp. (Apicomplexa: Eugregarinida: Actinocephalidae: Menosporinae) and Anguilloforma marcelyni (Actinocephalidae: Acanthosporinae) are described from adults of Ischnura ramburii and Enallagma civile (Odonata: Zygoptera: Coenagrionidae), respectively, from south and west Texas, U.S.A. Hoplorhynchus aster is the eleventh species described in the genus, and only the second reported from North America. It is distinguished from Hoplorhynchus acanthatholius by the number of digitations surrounding the epimerite disk (8 in H. acanthatholius vs. 14–18 in H. aster). Anguilloforma marcelyni gen. et n. sp. is distinguished from existing genera within Acanthosporinae by oocysts bearing a total of 14 spines (6 equatorial, 1 at each equatorial vertex, and 4 terminal spines inserted at each pole, 1 at each vertex created by polar truncations); mature trophozoites long and slender; and epimerite a simple, striated cup.

Allopodocotyle enkaimushi n. sp. (Opecoelidae: Plagioporinae) is described from the pyloric ceca and intestine of the short-tail grenadier, Nezumia proxima (Smith and Radcliff, 1912) (Gadiformes, Macrouridae), collected at depths of 681–1,061 m off Jōgashima Island, Sagami Bay, Japan. The new species is placed in Group C and is distinguished from its closest congener, Allopodocotyle margolisi Gibson, 1995, by possessing a terminal rather than a subterminal oral sucker; an unspecialized, inconspicuously elevated ventral sucker rather than being embedded in a well-developed ventral eminence that forms an anterior and lateral fold but with no distinct, muscular fold around the entire ventral sucker; a cirrus pouch that is entirely anterior to the ventral sucker rather than extending posteriorly to about the midlevel of it; and a sessile genital pore that is not situated on an eminence and surrounded by a muscular thickening of the body wall that appears to form a sphincter, as is the case in A. margolisi. In addition, A. enkaimushi n. sp. parasitizes a member of the grenadier genus Nezumia Jordan, 1904, from the west Pacific Ocean (Japan) rather than a species of the grenadier genus Coryphaenoides Gunnerus, 1765, from the North Atlantic Ocean. The combination of tandem testes, an entirely pre-acetabular cirrus pouch, and a pre-bifurcal (esophageal level) genital pore distinguishes A. enkaimushi n. sp. from all members of Group C recognized herein as well as from the 3 accepted species of Allopodocotyle Pritchard, 1966, already known from Japanese waters. A checklist of parasites reported from N. proxima is provided. We also furnish a key to the species in Groups A–C of Allopodocotyle, offer insights into the host familial diversity of shallow-water representatives in this genus, and hypothesize life histories for the 2 deep-water representatives in this genus.

A species of Eimeria new to science was discovered in fecal samples of mourning doves (Zenaida macroura) from Kentucky, U.S.A. Oocysts (n  =  57) are spherical to ovoid, 24.2 μm ± 0.6 × 20.7 μm ± 0.4 (23–25.5 μm × 20–21.5 μm), with an average length/width (L/W) ratio of 1.2 (1.1–1.3). The oocyst wall is double layered, smooth, and colorless. The outer wall is 1 μm, and the inner wall is extremely thin. Oocyst residuum and micropyle are absent, but 0–2 variably shaped polar granules (PG) are present. Most PG are sausage shaped (1 × 1.5 μm), while others are round or globular (~0.8–1 μm). Among the 57 oocysts, 54 had 1 PG, 2 had two PG, and 1 oocyst lacked a detectable PG. Sporocysts (n  =  83) are ovoid, 12.4 μm ± 0.5 × 7.3 μm ± 0.3 (12–13.8 μm × 6.9–8 μm), with an average L/W ratio of 1.7 (1.5–1.9). A knob-like Stieda body continuous with the sporocyst wall and a rounded substieda body are present. The sporocysts contained a sporocyst residuum made up of numerous granules of a uniform size (1 μm). Sporozoites are smooth with a terminal refractile body present. This is the third description of an Eimeria species from the genus Zenaida (Columbiformes: Columbidae) and the first report of Eimeria from the mourning dove.

Pontobdella californiana is described parasitizing California coastal water big skates, Raja binoculata, and thornback guitarfish, Platyrhinoidis triseriata. Leeches are large, up to 70 mm in total length. The oral sucker has 2 pairs of linear eyespots and 2 pairs of lateral papillae. The caudal sucker is small and terminal, with a diameter less than maximum body width. Annulus a2 has 4 large conical tubercles dorsally and 4 smaller conical tubercles ventrally. Annuli a1 and a3 have 4 small tubercles dorsally and ventrally and 2 small tubercles laterally for a total of 10 tubercles on each of these annuli.

During the summer of 2013, collection of glossiphoniid leeches from turtles in southern New England U.S.A. revealed several new host associations and geographic distribution records. Placobdella ali is reported for the first time from Massachusetts and Rhode Island. Placobdella hollensis is reported for the first time from mainland Rhode Island and for the first time from the common snapping turtle (Chelydra serpentina) and the stinkpot turtle or common musk turtle (Sternotherus odoratus). Helobdella papillata and Helobdella modesta were collected from common snapping turtles, and Helobdella lineata was collected from a stinkpot turtle. Data on the frequency of association of Helobdella spp. with aquatic vertebrates suggest that although Helobdella spp. are not parasitic, a symbiotic relationship likely exists between Helobdella spp. and their hosts, the nature of which is yet to be elucidated.

A new species, Androlaelaps delomys n. sp., (Acari: Mesostigmata: Laelapidae) is described from the sigmodontine rodent, Delomys dorsalis, collected in the Boraceia Biological Station in the state of São Paulo, Brazil. This mite is associated with the endemic rodent genus Delomys throughout the Atlantic Forest region of southeastern Brazil.

Recent work using DNA sequence data considered Homalometron armatum (McCallum, 1895) Manter, 1947 (Trematoda: Apocreadiidae) to consist of 3 species. The goal of the present investigation was to test, using new collections, whether these 3 putative species could be recognized and differentiated morphometrically. Newly collected worms from freshwater drum (Aplodinotus grunniens) and redear sunfish (Lepomis microlophus) in Texas, U.S.A., were combined with existing museum collections in multivariate analyses of morphometric characteristics. Principal components analysis on new collections suggested that worms did group by morphometric characteristics relativized by worm length. Discriminant function analyses demonstrated a high degree of fidelity between a priori classification of worms and the ability to discriminate among populations using morphometric data. Based on these results, the 2 as-yet undescribed species of Homalometron are named herein.

Nephromonorcha varitestis n. sp. (Digenea: Renicolidae) is described based on numerous specimens found in the kidneys of an American white pelican, Pelecanus erythrorhynchos Gmelin, 1789, collected in the Turtle Mountains, North Dakota, U.S.A. Nephromonorcha varitestis n. sp. differs from morphologically similar species in the body shape and proportions, sucker and sucker:body ratios, position and extent of vitellarium, and the shape of its ovary and testis. The morphological description of the new species based on light and scanning electron microscopy is provided. Nephromonorcha varitestis n. sp. is differentiated from all other members of Nephromonorcha and morphologically similar species of Renicola. Partial sequences of nuclear ribosomal rRNA gene are provided for future phylogenetic analyses. This is the first Nephromonorcha species reported from pelicans and only the second named renicolid species from pelicans in North America.

A species of Serendip Brooks and Barriga, 1995, Serendip danbrooksi n. sp., is described from Mexico as a parasite of Rhinoptera steindachneri Evermann and Jenkins, 1891. The new species differs from Serendip deborahae, the type and only other known member of the genus, by having bothridia subdivided by 2 septa, 1 simple and 1 bifurcating, rather than 3 septa, 2 simple and 1 bifurcating, and by having 37–61 testes versus 64–116 testes, respectively. In general, S. danbrooksi n. sp. is smaller than S. deborahae in the number of proglottids (average 77 vs. 150, respectively) and length (maximum length 15.3 mm vs. 60.0 mm, respectively). Clarification of the details of some previously described structures is discussed.

Two new species of Dactylogyridae (Monogenoidea) found parasitizing the gills of the pacu, Piaractus mesopotamicus (Holmberg, 1887), are described: Anacanthorus toledoensis n. sp. and Mymarothecium ianwhittingtoni n. sp. These monogenoideans were collected in the gills of all 38 pacus reared in cages in Toledo, State of Paraná, Brazil. Anacanthorus toledoensis n. sp. is characterized by the slightly sigmoid male copulatory organ (MCO) with a membranous flap along the longitudinal axis, which ends at the distal, spatulated portion of the organ, and by the rod-shaped accessory piece bearing a protruding median projection. Mymarothecium ianwhittingtoni n. sp. differs from all other species of the genus by the morphology of the anchors and by the structure of the copulatory complex comprising an arcuate MCO, with basal flap and accessory piece with a distal rod, somewhat sigmoid, and subterminal flap hooked.

Many modern-day studies require parasite samples essentially free of environmental contamination. Techniques used to prepare gastrointestinal nematode eggs from livestock are sufficient for biological studies but fall woefully short of generating pure preparations for downstream molecular, biochemical, and immunological studies. Consequently, a method to produce highly purified nematode parasite eggs free from fecal contamination is needed. The present study compared different procedures for egg isolation and attempted to improve the purity of Ostertagia ostertagi eggs isolated from cattle feces. The Wisconsin method using saturated sucrose has been used widely to enrich eggs from feces and is adequate for identification and counting. A more-recently developed method using the combination of salt and sucrose is robust and consistent and can be used to isolate eggs with much higher purity; however, residual fecal materials are still present in the egg preparations, which could account for large levels of nonspecific DNA and RNA contamination in the final samples. While large numbers of eggs can be harvested from the medium of overnight, in vitro-cultured adult worms, this method is labor intensive, involves euthanasia of animals, and requires the purification of adult worms to high purity and subsequent culturing to acquire the eggs. In addition, a large proportion of the eggs initiate development and hatch during isolation. In the current method, Ostertagia eggs free from fecal contamination were secondarily purified using lymphocyte separation medium (LSM) from eggs previously enriched by the Wisconsin method. The egg recovery following the LSM step was 100%. The results indicate that this two-step method involving sucrose and LSM was simple, rapid, nonselective, and greatly improved the purity of Ostertagia eggs. This method will have broad application for isolating eggs of the superfamily of Trichostrongyloidea, which includes the most-important nematode parasites infecting livestock.

One-hundred trout-perch, Percopsis omiscomaycus, collected from Saginaw Bay, Lake Huron in September 2011, were examined for parasites. Seven parasite species (1 Myxozoa: Myxobolus procercum; 1 Ciliophora: Trichodina sp.; 3 Digenea: Allacanthochasmus sp., Neochasmus sp., Crepidostomum percopsisi; 1 Nematoda: Camallanus oxycephalus; 1 Copepoda: Ergasilus luciopercarum) were found to infect trout-perch. Crepidostomum percopsisi had the highest prevalence (98%), mean intensity (5.3), and mean abundance (5.2). Ergasilus luciopercarum had a prevalence of 46% and a mean intensity of 2.6. Myxobolus procercum and Allacanthochasmus sp.–Neochasmus sp. (considered 1 taxonomic group) each had a prevalence of 22%. Trichodina sp. and C. oxycephalus infrequently infected trout-perch. Gravid individuals of only C. percopsisi and E. luciopercarum were found. Trichodina sp., Allacanthochasmus sp., Neochasmus sp., C. oxycephalus, and E. luciopercarum are reported for the first time from trout-perch in Lake Huron.

Echinococcus multilocularis can cause serious disease and even death in humans. Despite its human health implications, nearly 20 years have elapsed since the last surveys for E. multilocularis have been conducted in the United States. Between April 2009 and December 2012, 302 coyotes (Canis latrans), gray foxes (Urocyon cinereoargenteus), and red foxes (Vulpes vulpes) from Michigan were examined for E. multilocularis. The cestode was identified in 1 coyote (0.4%, n  =  223 coyotes) from the southwest portion of the state, representing the first report of E. multilocularis in this species in Michigan. Prevalence was lower than expected based on previous results in red foxes and coyotes in Michigan and nearby states.

This paper describes the first occurrence of Rhytidodoides similis Price, 1939, parasitizing a juvenile green turtle (Chelonia mydas Linnaeus, 1758) found on the coast of Brazil. This parasite is known only from C. mydas, with previous reports of occurrences in the liver and gall bladder of green sea turtles found in the United States, Panama, and Costa Rica. In this case, no gross or microscopic lesions were found on the liver associated with R. similis. However, microscopic analysis of the liver revealed granulomas of trematode eggs consistent with spirorchiids.

A new nematode species, Pterygodermatites (Paucipectines) andyraicola n. sp., is described from the small intestine of 4 neotropical species of Molossidae bats captured in São Paulo State, Brazil. The newly recognized species is characterized by the presence of a subterminal hexagonal oral opening with 24 triangular and prominent denticles of the same shape and size and a buccal capsule with 3 oesophageal teeth with jagged edges. The male has a robust body covered with 40 to 43 pairs of subventral cuticular spines, a coiled tail with thin caudal alae, 10 pairs of papillae, and a single, precloacal, semicircular cuticular fan on the ventral surface. The first pair of precloacal papillae are composed of 2 short pedunculated papillae, a feature that seems to be unique to P. (P.) andyraicola when compared to other species of the subgenus Pterygodermatites (Paucipectines). Equal spicules and the cone-shaped gubernaculum poorly sclerotized. The female has a robust body, thinner in the anterior portion, covered by 2 rows of 67 to 80 cuticular spines, of which the first 41 to 43 pairs are anterior to the vulvar opening and symmetrically arranged, which is in contrast to the asymmetrical disposition of the postvulvar spines. This is the 15th species in the genus described from mammals in the Neotropical ecozone and the third parasitizing bats in this biogeographic region.

The pathological and histopathological alterations associated with parasitic infection induced by the didymozoid Pozdnyakovia gibsoni Justo and Kohn, 2012, in the stomach wall of the skipjack tuna Katsuwonus pelamis (Linnaeus, 1758) in the southwestern Atlantic Ocean off South America are presented. The parasites were encysted in the mucosal layer of the stomach and inserted into the connective tissue that forms the lamina propria. The parasite penetrates through the stomach wall, inducing white blood cell proliferation and a localized inflammatory reaction.

The digestive tracts of 8 Chalcides ocellatus, now established in Mesa, Maricopa County, Arizona, U.S.A., were examined for helminths. Found were 2 species of Nematoda previously restricted to the Old World, Moaciria icosiensis and Spinicauda sonsinoi. The New World is a new host locality for M. icosiensis and S. sonsinoi. The helminth fauna of New World C. ocellatus (2 species of Nematoda) is depauperate when compared to that of Old World (Turkey) C. ocellatus, which contained 1 species of Digenea, 1 species of Cestoda, and 6 species of Nematoda.

Forty-seven dark-sided salamanders (Eurycea longicauda melanopleura) were collected from 5 counties of northern Arkansas and examined for helminth parasites. Twenty-four (51%) were infected with 1 or more helminths, including 8 (17%) with Brachycoelium salamandrae, 8 (17%) with Bothriocephalus rarus, 3 (6%) with Omeia papillocauda, 5 (11%) with Oswaldocruzia euryceae, 1 (2%) with Desmognathinema nanthalaensis, 1 (2%) with Cosmocercoides variabilis, and 2 (4%) with Amphibiocapillaria tritonispunctati. Five (11%) were concurrently infected with various helminths. We document new host records for the digenean B. salamandrae and the nematodes A. tritonispunctati, D. nanthalaensis, and O. papillocauda.

Biological inventories often miss parasites, a critical component of biodiversity, and even well-studied host species generally have a paucity of parasite records. Efforts to document the host diversity and distribution of parasites can use newly collected specimens as well as museum specimens. We focus on a group of widespread, well-documented hosts, western North American chipmunks (Rodentia: genus Tamias). Field-collected and museum specimens of chipmunks from across western North America were examined externally for sucking lice (Anoplura), and gastrointestinal tracts were examined for pinworms (Oxyuriodea). We documented new hosts and expanded the geographic distribution for four parasite taxa under investigation: Hoplopleura arboricola, Neohaematopinus pacificus, Heteroxynema cucullatum, and Rauschtineria eutamii. This effort demonstrates the utility of museum collections as well as the pressing need for continued field collection to characterize global biodiversity.