Use of the host individual as a boundary for parasite populations and communities provides an unambiguous spatial unit that is useful for pattern description, but this framework precludes consideration of the host landscape and within-host population dynamics. Recognizing host individuals as spatially and temporally complex landscapes requires modified concepts of parasite populations and communities. An outline of the currently accepted hierarchies of parasite populations and communities is provided on the basis of ecological neighborhoods that are delineated by discrete habitat patches or functional dynamics (or both), as opposed to host individuals. This parasite-based framework accommodates consideration of both within- and among-host dynamics and facilitates investigation into the mechanisms by which these 2 levels of investigation interact.

Fecal samples were collected from 6 African forest elephants, Loxodonta africana cyclotis, from the Nouabalé-Ndoki National Park, Republic of Congo, and the Dzangha-Sangha National Park, Central African Republic. One of the elephants was found freshly dead from natural causes, and 12 species of intestinal parasites (2 bot fly larvae, 1 trematode, and 9 nematodes) were collected during a complete necropsy. In addition, fecal samples revealed the presence of a schistosome, Bivitellobilharzia sp., a tracheal nematode, Mammomonagamus sp., and a complex of intestinal strongylids and ciliates. The nematode genera Decrusia and Equinurbia are reported for the first time from African elephants, and the ciliate genus Latteuria is reported for the first time from wild elephants. The parasite fauna of the African elephant is discussed in the light of recent genetic evidence that the forest and savannah elephants may be separate species.

A study was conducted on the occurrence of 2 Diphyllobothrium species in 5 species of fish from Lake Panguipulli in southern Chile and in dogs and humans associated with the lake. Fish were examined for plerocercoid larvae, and human and dog feces from the towns of Panguipulli and Choshuenco were sampled for the presence of tapeworm ova. Odonthestes (Cauque) mauleanum (Steindachner, 1896) is reported for the first time as a host for both Diphyllobothrium latum Linnaeus, 1758, and Diphyllobothrium dendriticum (Nitzsch, 1824). Basilichthys australis Eigenmann, 1927, is reported for the first time as a host for D. latum. Prevalences and mean intensities of D. latum and D. dendriticum were higher in introduced trout, Oncorhynchus mykiss (Walbaum, 1792), than in the native fishes, O. (C.) mauleanum, B. australis, Percichthys trucha (Valenciennes, 1833), and Galaxias maculatus (Jenyns, 1842). Prevalence and mean intensities of Diphyllobothrium spp. were similar (P > 0.05) in fish of both sexes. Intensities of infection by Diphyllobothrium spp. showed significant correlation (P < 0.05) with length in trout. Human infection by adults of D. latum was detected only at Choshuenco, with a prevalence of 2.8%. In this locality 12.5% of the people consumed smoked fish, showing a significant difference compared with Panguipulli, where 5.2% of the people consumed smoked or raw fish. No significant difference was detected in prevalence of infection in dogs in Panguipulli (1.8%) and Choshuenco (4.5%).

Distribution and host use of the 9 species of Neoechinorhynchus (Acanthocephala: Neoechinorhynchidae) described from turtles are summarized from a comprehensive evaluation of the specimen base in the major parasitology museums of the United States. Each specimen in each lot was examined and its identity verified, if possible. Verified specimens were used to construct a specimen-based known distribution and list of definitive hosts for each species. Five species (Neoechinorhynchus chrysemydis, Neoechinorhynchus emydis, Neoechinorhynchus emyditoides, Neoechinorhynchus pseudemydis, and Neoechinorhynchus stunkardi) have broad distributions in North America, whereas Neoechinorhynchus chelonos and Neoechinorhynchus lingulatus are currently known only from eastern states, and Neoechinorhynchus magnapapillatus is known from the eastern Atlantic seaboard, Florida, and the coast of the Gulf of Mexico. Neoechinorhynchus schmidti is known only from Mexico. Host use is confined largely to emydid turtles; reports from turtles in other families are sporadic, and most of the turtle species of North America have not been surveyed adequately for acanthocephalans. The specimen base for the species of Neoechinorhynchus of turtles is unsuitable for most taxonomic purposes; it is composed of small lots of specimens with few identifiable worms that are, on average, in poor physical condition. Future biodiversity studies of this group will require significant new specimen collections to answer questions of host use, evolutionary relationships, and biogeography.

Current practice in gregarine (Apicomplexa: Eugregarinorida) taxonomy does not include a standard nomenclature and metric set for plane shapes even though most taxonomic works within the group depend on shape-based descriptions. The lack of a uniform shape nomenclature and metric set has produced considerable confusion in gregarine systematics: descriptions of species often are not directly comparable even among congeneric taxa. As a step toward unifying taxonomic practice within Eugregarinorida, a standard nomenclature and metric set for 278 plane shapes in 23 shape series is delineated.

Calyxocephalus karyopera g. nov., sp. nov. (Apicomplexa: Eugregarinorida: Actinocephalidae: Actinocephalinae) is described from the Ebony Jewelwing Damselfly Calopteryx maculata (Odonata: Zygoptera: Calopteryigidae) collected along Turkey Creek in Johnson County, Nebraska, U.S.A. Calyxocephalus gen. n. is distinguished by the form of the epimerite complex: a terminal thick disk or linearly crateriform sucker with a distal apopetalus calyx of petaloid lobes and a short intercalating diamerite (less than half of the total holdfast length). The epimerite complex is conspicuous until association and syzygy. Association occurs immediately before syzygy and is cephalolateral and biassociative. Gametocysts are spherical with a conspicuous hyaline coat. Lacking conspicuous sporoducts they dehisce by simple rupture. Oocysts are axially symmetric, hexagonal dipyramidic in shape with slight polar truncations, bearing 6 equatorial spines, 1 at each equatorial vertex and 6 terminal spines obliquely inserted at each pole, 1 at each vertex created by polar truncation. The ecology of the C. karyopera–C. maculata host–parasite system provides a mechanism for mechanical prey–vector stabilization of exogenous gregarine development and isolation.

During 1991–1992 and 1999–2000, domestic dogs (n = 611) and cats (n = 71) from animal shelters in Anderson, Pickens, and Oconee counties in northwestern South Carolina, U.S.A., were examined for the filarial heartworm, Dirofilaria immitis. For both dogs and cats, whole blood was collected and tested for microfilaria using the Modified Knott's technique. In an effort to find adult heartworms in cats only, a gross necropsy of heart, lungs, and pulmonary vessels was performed immediately after municipal euthanasia. Plasma from each cat was tested for anti–D. immitis antibodies and D. immitis antigens using in-house antibody and antigen tests. In the 1991–1992 study, 21 of 242 dogs (8.7%) were positive for D. immitis. The prevalence of heartworm in dogs increased to 12.7% (47 of 369 dogs) in 1999–2000. Another species of filarial worm, Dipetalonema reconditum, also was observed in blood samples from dogs (18 of 242 dogs [7.44%] and 28 of 369 dogs [7.6%] in 1991–1992 and 1999–2000, respectively). The prevalence of the nonpathogenic D. reconditum was not significantly different from that of D. immitis, emphasizing the importance of correct diagnosis of circulating microfilaria. Modified Knotts' and gross necropsy of cats revealed no heartworms, but 5 of 71 (7%) plasma samples were positive for heartworm antibodies.

The diagnosis of Diplectanocotyla (Monogenoidea: Dactylogyridea) is emended, the genus is transferred to the Diplectanidae, and the Diplectanocotylidae is considered a junior synonym of the Diplectanidae. Diplectanocotyla megalopis is redescribed from gills of Atlantic tarpon, Megalops atlanticus (Megalopidae), from the Atlantic coasts of Nicaragua and Mexico (new host and locality records). Although D. megalopis was previously found on the Atlantic tarpon in Puerto Rico, the species from this host was originally misidentified as Diplectanocotyla gracilis. Diplectanocotyla is differentiated from other diplectanid genera by its members having a haptor with 2 central suckers (1 ventral, 1 dorsal) and paired ventral bars, a pair of squamodiscs with concentric rows of scales, a spined tegument of the posterior trunk and peduncle, an ovary looping the right intestinal cecum, and a vas deferens looping the left intestinal cecum.

Oxyuronema Kreis, 1932 and Buckleyenterobius Sandosham, 1950 are reestablished as subgenera of Trypanoxyuris Vevers, 1923 (Nematoda: Oxyuridae) by dividing Paraoxyuronema sensu Hugot et al., 1996. Trypanoxyuris (Oxyuronema) atelophora Kreis, 1932 n. comb. and Trypanoxyuris (Buckleyenterobius) atelis (Cameron, 1929) are redescribed based on both sexes collected from the black-handed spider monkey, Ateles geoffroyi (Primates: Cebidae). The male of T. (O.) atelophora is described for the first time. It is also first shown that T. (B.) atelis possesses a round hyaline structure at the distal tip of spicule and eggs with 3 longitudinal ridges on the shell.

Fecal samples were collected from 61 adult raccoons (Procyon lotor) livetrapped on Key Largo, Florida, U.S.A. (25°15′N; 80°15′W), between April and November 2002 and analyzed for intestinal coccidia. Eimeria procyonis (84%), Eimeria nuttalli (10%), 1 unidentified species of Eimeria (3%), and an unidentified species of Sarcocystis (3%) were found. No oocyst of Cryptosporidum was found on a fecal smear stained with Kinyoun carbol-fuchsin acid-fast stain.

A total of 15 species of helminths (2 trematodes, 10 nematodes, 2 acanthocephalans, and 1 protozoan) were recovered from 21 crested goshawks (Accipiter trivirgatus formosae) from Taiwan. Sixteen of 21 birds (76.2%) were infected, and 6 of them had ≥4 species of parasites. Most of the parasites were in the gastrointestinal tract. Infection of other sites (e.g., liver, body cavity, air sac) was uncommon. Intensities of infection were low, and no lesions were attributed to the parasites. Most of the species appear to be generalists in raptors and remained generalists in other birds. Lutztrema monoteron, Ascaridia perspicillus, Dispharynx nasuta, Spirocerca sanguinolenta, Raphidascaris sp., and Caryospora sp. are reported here for the first time from Accip. t. formosae. Most of the parasites recovered from Accip. t. formosae require mammals, amphibians, and reptiles as paratenic or intermediate hosts. This article is the first to detail the endoparasites of Accip. t. formosae in Taiwan.

During field surveys in Cape York, Australia, a new genus was recovered from Rattus leucopus, the Cape York rat. Study of the morphology, particularly of the anterior end, showed that Spirosprattus scyphiformis n.g., n. sp. is distinguished from all other species of the Spirocercidae and falls within the subfamily Ascaropsinae. All other ascaropsines are either cosmopolitan in distribution, occurring in bovids, cervids, or suids, or found in hosts endemic to South America. There is, however, insufficient evidence to establish the relationships between S. scyphiformis and spirocercids from cosmopolitan, Southeast Asian, or Australian marsupial hosts.

This study presents results from a survey of helminth parasites of fishes in the Pánuco River basin, in the states of San Luis Potosí, Hidalgo, Querétaro and Guanajuato, all in east central Mexico. Seventeen freshwater fish species (n = 1,019) were examined for helminths between May 1997 and September 1998. Thirty-one helminth species were collected: 11 allogenic species, mostly Nearctic in origin, and 20 autogenic species. Two anthropogenically introduced species were recorded. The most prevalent and widespread helminth taxon was Posthodiplostomum minimum (metacercariae). The helminth fauna of fishes of the Pánuco River is dominated by trematodes (12 species) and nematodes (11 species) accompanied by a few monogenean (4 species), cestode (3 species), and acanthocephalan (1 species) taxa. Most of the helminth taxa reported have been reported from other regions of Mexico. Thus, the helminth parasite fauna of fishes of the Pánuco River basin are not exclusive, including a primordially autogenic Neotropical species component mixed with a mainly allogenic, globally distributed Nearctic species component. The regional freshwater fish helminth fauna is associated with the ichthyofaunanal composition of the basin. The nematode family Rhabdochonidae displays high species richness in this hydrological basin of Mexico.

Seventy-seven of 81 (95%) Tropidurus guarani collected in Ybycui National Park, Paraguay were found to harbor 1 or more of 7 helminth species: Oochoristica bresslaui, Parapharyngodon scleratus, Piratuba digiticaudata, Physaloptera lutzi, Spauligodon oxkutzcabiensis, Strongyluris oscari, and Skrjabinelazia intermedia. All represent new host and new locality records.

Twenty-five lizards representing 2 species of Leiosauridae, Leiosaurus belli and Leiosaurus catamarcensis, and 10 species of Liolaemidae, Liolaemus andinus, Liolaemus buergeri, Liolaemus chiliensis, Liolaemus elongatus, Liolaemus lemniscatus, Liolaemus neuquensis, Liolaemus pictus argentius, Liolaemus tenuis, Liolaemus vallecurensis, and Phymaturus palluma, from Argentina were examined for endoparasites. One species of Cestoda, Oochoristica travassosi, 3 species of Nematoda, Physaloptera retusa, Parapharyngodon riojensis, and Spauligodon maytacapaci, and 1 species of Pentastomida, Kiricephalus sp. (nymphs), were found. Twelve new host records are reported.

A survey of soils from Iceland for the presence of cold-active entomopathogenic nematodes yielded a single isolate of Steinernema kraussei. This isolate was compared morphologically with the topotype from Westphalia, Germany, and was found to be similar except that the strain from Iceland had shorter mucrons and a longer gubernaculum in second-generation males. A fragment of the ribosomal DNA (internal transcribed spacer 1 [ITS1] 5.8S ITS2) was amplified and sequenced along with 7 other isolates of S. kraussei, 2 isolates from Switzerland, 1 isolate from Scotland, and 4 isolates from Russia. Phylogenetic trees prepared using maximum parsimony methods placed the strain from Iceland in a cluster with 2 Russian strains. The virulence of S. kraussei from Iceland against larvae of Tenebrio molitor was compared with that of a commercially available strain of Steinernema feltiae at 12°C and 4°C. At 12°C the strain from Iceland was less virulent than S. feltiae, and at 4°C the strain from Iceland demonstrated no detectable virulence, whereas S. feltiae evinced limited virulence.

A total of 142 bass (54 Micropterus dolomieu and 88 Micropterus salmoides) were collected April through September 2000 and April through July 2001 from 5 locations in Gull Lake, Michigan, U.S.A., and examined for Proteocephalus ambloplitis. Proteocephalus ambloplitis was 100% prevalent in both smallmouth and largemouth bass. The numbers of P. ambloplitis from each microhabitat (gonads, liver, spleen, mesentery, pyloric ceca, intestine) were counted and compared between females and males within and between host species. Overall mean intensity of infection and mean intensity in the ovaries was significantly higher in smallmouth bass. Infections among smallmouth bass were most intense in the gonads but most intense in the liver and mesentery among largemouth bass. Given the known pathology of P. ambloplitis, bass tapeworm may reduce the reproductive potential of smallmouth bass in Gull Lake.

We describe an unusual behavior observed in a noctuid caterpillar infected by juvenile forms of a cestode. The caterpillar ate the parasites from a membranous sac located in the final segment of the body. Some comments on this structure and behavior are made in connection with the life cycle of the parasite.

A total of 230 feral African clawed frogs, Xenopus laevis, from 3 localities in southern California were examined for parasites. The following species were found: 3 species of Protozoa, Nyctotherus sp., Balantidium xenopodis, Protoopalina xenopodus; 2 species of Monogenea, Protopolystoma xenopodis, Gyrdicotylus gallieni; 1 species of Digenea, Clinostomum sp. (as metacercariae); 1 species of Cestoda, Cephalochlamys namaquensis; 2 species of Nematoda, Contracaecum sp. (as larvae), Eustrongylides sp. (as larvae); and 1 species of Acanthocephala, Acanthocephalus sp. (as cystacanth). Of these, the protozoans P. xenopodus and B. xenopodis, both monogeneans, and the cestode have an African origin. Contracaecum sp., Eustrongylides sp., and Acanthocephalus sp. have not been previously reported from X. laevis.

Between the spring of 1999 and the spring of 2002, 196 conger eels, Conger conger, were collected from the Ría de Arousa, Galicia, Spain, and examined for hemiurid flukes. Five trematode species belonging to the family Hemiuridae were found: Hemiurus communis, Lecithochirium fusiforme, Lecithochirium rufoviride, Lecithochirium furcolabiatum, and Lecithochirium musculus. The 2 most common species were L. fusiforme and L. rufoviride, each with a prevalence of more than 80%. Furthermore, both species occurred simultaneously in 145 conger eels (74%). In contrast to the population of L. rufoviride, the mean intensity and abundance of L. fusiforme revealed a clear seasonal pattern, with peak values coinciding with each of the 3 winters studied. However, the prevalence of L. fusiforme did not increase significantly during winter. These differences may be related to an aggregated distribution of the parasite. The results show that infrapopulations of this species fluctuate greatly in the host with time and suggest that this parasite matures relatively quickly but does not survive for much longer than 3 mo in conger eels.

The acuarioid nematode Paracuaria adunca (Creplin, 1846) was found in 7 of 13 (54%) Larus dominicanus (Aves: Laridae) examined from several locations along the Argentine coast. It was only present in specimens from Patagonia; the intensity of infection ranged from 1 to 14 (mean = 5.4). This is the first record of P. adunca from South America and as a parasite of L. dominicanus. Using both light and scanning electron microscopy (SEM), the complexity of the left spicule and the number and arrangement of male caudal papillae were observed. Although P. adunca is parasitic in several unrelated bird families and has a wide geographical distribution, the dimensions of our specimens fully agree with previous reports. The genus Paracuaria was characterized by the presence of rudimentary cordons; thus, it was considered the most primitive acuarioid. The cordons appear as finger-like structures within shallow grooves held tightly against the surface and extend posteriorly from the ends of the mouth and for this reason cannot be easily seen under SEM.

During investigations of digenetic fluke diseases of aquaculture fish, 11 digeneans (Apharyngostrigea simplex, Apharyngostrigea cornu, Diplostomum compactum, Diplostomum spathaceum, Posthodiplostomum minimum, Hysteromorpha triloba, Clinostomum marginatum, Drepanocephalus spathans, Mesorchis denticulatus, Microparyphium facetum, and Notocotylus pacifera) were collected from 5 species of piscivorous birds (Ardea herodias, Fulica americana, Larus delawarensis, Nycticorax nycticorax, and Phalacrocorax auritus) from North Carolina, U.S.A. Apharyngostrigea simplex from A. herodias represents a new host record. Diplostomum spathaceum, P. minimum, C. marginatum, and M. denticulatus have previously been reported from North Carolina; the remainder represent new locality records.

We report a specimen of Cardicola forsteri Cribb, Daintith, and Munday, 2000 (Digenea: Sanguinicolidae) from the lumen of the heart of a northern bluefin tuna, Thunnus thynnus (Linnaeus, 1758) (Scombridae), that was 218 cm in total length (TL) and caught in the northwest Atlantic Ocean 12 km south of Cape Lookout, North Carolina. The hearts of 12 similarly sized northern bluefin tuna (127–262 cm TL) from George's Bank, northwest Atlantic Ocean, were not infected. This is the first report of C. forsteri from a wild host and of a sanguinicolid from any scombrid in the northwest Atlantic Ocean. Bluefin tuna is cultured in sea cages because of its highly prized flesh, and the fact that a blood fluke infects this host is significant because some blood flukes have been identified as serious pathogens of cage-cultured fish.

Air-dried smears of trichodinids were collected from cultured marine flatfishes of the families Pleuronectidae and Scophthalmidae at 2 localities in Atlantic Canada and stained using Klein's dry-silver impregnation technique to reveal the morphology of the adhesive disk. Two species were identified: Trichodina jadranica from the skin of captive broodstock of Pleuronectes americanus, Limanda ferruginea, Hippoglossus hippoglossus, and Scophthalmus aquosus and Trichodina hippoglossi from the skin of juvenile and broodstock H. hippoglossus. The former parasite has an extensive distribution in marine seas worldwide and has broad host specificity. The latter parasite is known only from the North Atlantic Ocean and has been found only on H. hippoglossus. This study represents the first confirmed identifications of Trichodina from pleuronectiform fishes in Atlantic Canada and the first reports of these species in Canadian waters.

The pentastome Raillietiella indica was collected from the introduced toad Bufo marinus in Oahu, Hawaii, U.S.A. The parasite was identified as R. indica from similarities in morphology of the hooks, buccal cadre, and male copulatory spicule. This represents a new host record for this parasite, previously only recorded from Bufo melanostictus. This also represents a new locality record because this parasite has only been reported previously in India, Burma, and Taiwan. This is the third record of B. marinus as a host for parasites in Hawaii.

Nineteen black marsh turtles, Siebenrockiella crassicollis, confiscated by international authorities in Hong Kong, People's Republic of China, on 11 December 2001 were examined for endohelminths. Turtles were either frozen or placed on ice and shipped to the Texas Cooperative Wildlife Collection, Texas A&M University, College Station, Texas, U.S.A., for examination. Eighty-nine percent of the black marsh turtles examined was infected with helminthes, with an average of 1.6 species per infected turtle. Prevalences of collected helminths were as follows: 1 unidentified proteocephalid tapeworm (5%), 2 nematodes (Falcaustra duyagi [74%] and Serpinema octorugatum [21%]), 3 digeneans (Diaschistorchis multitesticularis [11%], Stunkardia dilymphosa [11%], and Telorchis cyclemidis [21%]), and 1 aspidogastrean (Multicotyle purvisi [26%]). Eggs from a species in Spirorchidae were also found in the intestinal wall of 1 turtle.

The helminth fauna of 73 tree frogs, Hyla arborea, in the Antalya province of southwestern Turkey comprised 6 species: Polystoma skrjabini Buchvarov, 1984, Pleurogenoides medians (Olsson, 1876), Encyclometra colubrimurorum (Rudolphi, 1819) Dollfuss 1929 (metacercariae), Proteocephalus sp. Weinland, 1858 (Pleurocercoid stage), Cosmocerca commutata (Diesing, 1861), and Acanthocephalus ranae (Schrank, 1788). All parasites collected represent new host records for H. arborea in Turkey. This is the first report of the monogenetic trematode P. skrjabini from Turkey.

Two experiments were conducted to study the influence of salinity and desiccation on the development of first-stage larvae in eggs of Eustrongylides ignotus. In cultures of low salinities (0, 10, and 20 parts per thousand [ppt]) 54% to 60% of the eggs contained first-stage larvae by day 90, but no development occurred in the eggs incubated in seawater (40 ppt). Development of eggs in cultures that were exposed to sunlight and allowed to dry down was ca. 1%, whereas 57% to 62% development occurred in cultures maintained in deionized water.