The effects of aestivation or starvation on the neutral lipid and phospholipid content of Biomphalaria glabrata patently infected with Schistosoma mansoni were determined by high-performance thin-layer chromatography–densitometry. Infected–aestivated snails were maintained in a moist chamber at 24 ± 1 C and a relative humidity of 98 ± 1%. Infected–starved snails were maintained in artificial spring water (ASW) at 23 ± 1 C without exogenous food. Infected snails (the controls) were maintained in ASW at 23 ± 1 C and fed lettuce ad libitum. The 3 groups were maintained in the laboratory for 7 days, and then the lipids from the digestive gland–gonad complex (DGG) were extracted and analyzed by class. Infected–aestivated snails exhibited greater mortality rate and weight loss after 7 days than did the infected–starved snails. The steryl ester concentration in the infected–starved snails was significantly increased (P = 0.010) compared with the controls but not compared with infected– aestivated snails; the concentration of phosphatidylcholine in infected–aestivated snails was significantly decreased (P = 0.007) compared with the controls but not when compared with the infected–starved snails. Aestivation or starvation had a significant effect on the concentration of certain lipid classes in the DGG of B. glabrata infected with S. mansoni.

The distal bothridial surfaces of adult triloculate onchobothriids are covered with short structures that have been tentatively classified as very short filitriches, but this hypothesis has never been tested. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to investigate microthrix morphology in the plerocercoid and adult forms of Calliobothrium cf. verticillatum, a triloculate onchobothriid tapeworm from Long Island Sound (Connecticut). Plerocercoids of C. cf. verticillatum were collected from the anterior midgut ceaca of Pagurus pollicaris Say, 1817 (flat-clawed hermit crab), and adults were collected from the spiral intestine of the dusky smooth hound Mustelis canis (Mitchell, 1815). Two plerocercoids and 2 adults were examined using SEM; 2 plerocercoids and 2 adults were examined using TEM. Microthrix distribution and morphology (including measurements of total length, base length, shaft length, and base width) were investigated on all surfaces of the plerocercoid and adult scolex. Slender filitriches and large bladelike spinitriches were observed extending from the tegument of plerocercoid and adult forms. The filitriches were found to have significantly narrower bases than the spinitriches (65–167 nm vs. 466–1,936 nm, respectively). The scolex proper of the plerocercoid and adult forms were found to have filitriches of medium-length and bladelike spinitriches. The distal bothridial surfaces differed dramatically in microthrix morphology between plerocercoid and adult forms; on the distal surfaces of the plerocercoids were long filitriches and bladelike spinitriches. However, the distal surfaces of the adults had short structures (previously hypothesized to be short filitriches) and a few bladelike spinitriches. Serial transverse sections revealed that the short structures on the distal bothridial surfaces of the adults were homologous with filitriches. They included all of the structural components of a filithrix as well as a base width that conformed to the filitriches found on other surfaces. The bothridial margins of the plerocercoid and adult forms had a microthrix pattern similar to that seen on the proximal bothridial surfaces except that the filitriches on the margins were significantly longer than those found anywhere else on the bothridia. The most dramatic difference between the plerocercoid and adult forms occurred on the distal bothridial surfaces, where the filitriches of the adult cestodes were significantly shorter and narrower, and the spinitriches were almost entirely lacking.

Few studies on the relationship between environmental factors and Trypanosoma cruzi transmission have been conducted in Ecuador. We conducted a cross-sectional study of household risk factors for T. cruzi seropositivity in 2 distinct geographical regions of Ecuador. Exposure information was collected via household surveys, and subjects were tested for serological evidence of T. cruzi infection. In total, 3,286 subjects from 997 households were included. In the coastal region, factors associated with seropositivity were living in a house with a palm roof (odds ratio [OR] = 2.63, 95% confidence interval, [1.61, 4.27]), wood walls (OR = 5.75 [2.04, 16.18]), or cane walls (OR = 2.81 [1.31, 6.04]), and the presence of firewood in the peridomicile (OR = 2.48 [1.54, 4.01]). Accumulation of trash outside the home was associated with a reduced risk of seropositivity (OR = 0.25 [0.12, 0.51]). In the Andean region, living in a house with adobe walls was the only factor predictive of T. cruzi seropositivity. In conclusion, risk factors for T. cruzi transmission in Ecuador varied by geographic region, probably because of differing behavior of the triatomine vector species in each region. An understanding of the transmission dynamics of T. cruzi in a particular area is necessary for the development of effective Chagas disease control strategies in those areas.

The role of ecological and phylogenetic processes is fundamental to understanding how parasite communities are structured. However, for coral reef fishes, such information is almost nonexistent. In this study, we analyzed the structure of the parasite communities based on composition, richness, abundance, and biovolume of ecto- and endoparasites of 14 wrasse species (Labridae) from Lizard Island, Great Barrier Reef, Australia. We determine whether the structure of the parasite communities from these fishes was related to ecological characteristics (body size, abundance, swimming ability, and diet) and/or the phylogenetic relatedness of the hosts. We examined 264 fishes from which almost 37,000 individual parasites and 98 parasite categories (types and species) were recorded. Gnathiid and cestode larvae were the most prevalent and abundant parasites in most fishes. Mean richness, abundance, and biovolume of ectoparasites per fish species were positively correlated with host body size only after controlling for the host phylogeny, whereas no such correlation was found for endoparasites with any host variable. Because most ectoparasites have direct transmission, one possible explanation for this pattern is that increased space (host body size) may increase the colonization and recruitment of ectoparasites. However, endoparasites generally have indirect transmission that can be affected by many other variables, such as number of prey infected and rate of parasite transmission.

Janinecaira darkthread n. gen., n. sp. (Eudactylinidae, Siphonostomatoida, Copepoda) infects gills of the ornate eagle ray Aetomylaeus vespertilio (Bleeker, 1852) (Myliobatidae, Myliobatiformes) in the Beagle Gulf (Timor Sea, eastern Indian Ocean) off northern Australia. The adult female of Janinecaira darkthread n. sp. is most easily distinguished from other eudactylinids (Eudactylinidae) by its long genital complex that comprises about 86–90% of the total body length. A diagnostic key to genera of Eudactylinidae based on adult females is provided.

Nine species of Siganus (Perciformes: Siganidae) were examined for dactylogyrids (Monogenoidea) from the Red Sea, Egypt; the Great Barrier Reef, Australia; and the South China Sea, China. Species of Tetrancistrum were found on siganids from all 3 localities; Pseudohaliotrema spp. were restricted to siganids from the Great Barrier Reef; and species representing Glyphidohaptor n. gen. were found on siganids from the Red Sea and Great Barrier Reef. Siganus argenteus from the Red Sea and Siganus vulpinus from the Great Barrier Reef were negative for dactylogyrid parasites. Glyphidohaptor n. gen. is proposed for 3 species (2 species new to science) and the new species are described: Glyphidohaptor phractophallus n. sp. from Siganus fuscescens from the Great Barrier Reef; Glyphidohaptor sigani n. sp. from Siganus doliatus (type host), Siganus punctatus, Siganus corallinus, and Siganus lineatus from the Great Barrier Reef; and Glyphidohaptor plectocirra (Paperna, 1972) n. comb. (=Pseudohaliotrema plectocirra Paperna, 1972) from Siganus luridus and Siganus rivulatus from the Red Sea.

Flea, lice, mite, and tick species associated with 510 Rhabdomys pumilio were collected at 9 localities in the Western Cape Province, South Africa. The aims of the study were first to quantify the species richness, prevalence, and relative mean intensity of infestation of epifaunistic arthropod species associated with R. pumilio, and second to determine temporal variations in the mean abundance of the parasitic arthropods. Each mouse was examined under a stereoscopic microscope and its parasites were removed, identified, and quantified. The epifaunal population was made up of more than 25,000 individuals and included 8 flea, 1 sucking louse, 11 mite, and 13 ixodid tick species. Female-biased sex ratios were noted for 9 (30%) of the ectoparasite species. Three undescribed mite and 1 undescribed tick species were recovered, and new locality records for 2 flea, the louse, and 2 mite species were documented. A phoretic host association between a nonparasitic mite species, Psylloglyphus uilenbergi kivuensis, and 3 flea species, Chiastopsylla rossi, Hypsophthalmus temporis, and Listropsylla agrippinae, was recorded. The mean abundance of the parasitic mite and insect species were higher during the cold wet season, whereas ticks were more numerous during the warm dry months. The large number of ectoparasite species on R. pumilio, a locally abundant and regionally widespread species, is of medical and veterinary importance particularly in relation to the transmission of pathogens such as Anaplasma marginale, Babesia caballi, and Babesia canis to domestic animals; Rickettsia conori; Yersinia pestis; and the viral disease Crimean-Congo hemorrhagic fever to humans.

The prevalence of Toxoplasma gondii in 118 unwanted dogs from São Paulo City, São Paulo State, Brazil, was determined. Antibodies to T. gondii were assayed by the modified agglutination test and found in 42 (35.8%) dogs, with titers of 1:20 in 10, 1:40 in 6, 1:80 in 5, 1:160 in 5, 1:320 in 6, 1:640 in 7, and 1:1,280 or higher in 3. Hearts and brains of 36 seropositive dogs were bioassayed in mice, or cats, or both. Tissues from 20 seropositive dogs were fed to 20 T. gondii–free cats. Feces of cats were examined for oocysts. Toxoplasma gondii was isolated from 15 dogs by a bioassay in mice, from the brain alone of 1, from the heart alone of 4, and from both brains and hearts of 10. All infected mice from 5 of 15 isolates died of toxoplasmosis during primary infection. Four additional isolates were obtained by bioassay in cats. Genotyping of these 19 T. gondii isolates using polymorphisms at 10 nuclear markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and a new SAG2 (an apicoplast marker Apico) revealed 12 genotypes. One isolate had Type III alleles at all 11 loci, and the remaining 18 isolates contained a combination of different alleles and were divided into 11 genotypes. The absence of Type II in Brazil was confirmed. The result supports previous findings that T. gondii population genetics is highly diverse in Brazil.

This study reports a new capture ELISA (MM3-SERO) for the serodiagnosis of sheep fascioliasis, based on the use of the monoclonal antibody (mAb) MM3. Like our previously reported indirect ELISA method, based on the use of a FPLC-purified fraction (fraction IV) of the Fasciola hepatica excretion/secretion antigens (ESAs), this new test was able to detect animals infected with very small numbers of metacercariae (5–40) and showed no cross-reaction with sera from sheep infected with other parasites, i.e., Moniezia spp., Cysticercus tenuicollis, and Dicrocoelium dendriticum. In contrast with these 2 methods, some sera (mainly those obtained from animals infected with D. dendriticum) showed high reactivities in indirect ELISA with whole F. hepatica ESAs used as control. Interestingly, the MM3-SERO ELISA has a better signal-to-noise ratio than the fraction-IV ELISA, thus allowing detection of seroconversion in infected sheep on average 1 wk earlier (3.2 ± 0.4 wk postinfection [PI] for MM3-SERO ELISA vs. 4.2 ± 0.9 wk PI for fraction IV ELISA). Moreover, the antibody response detected with MM3-SERO ELISA was more uniform, with seroconversion always occurring at 4 wk PI in sheep with 1–2 flukes and at 3 wk PI in sheep with more than 2 flukes. The MM3-SERO ELISA was also used to evaluate the kinetics of antibody response against MM3-recognized antigens in sera from sheep experimentally infected with F. hepatica and then treated with triclabendazole. Our results showed that antibody levels dropped by about 25% during the 4-wk observation period following the flukicide treatment, whereas they remained invariably high in all sheep left untreated. We conclude that the MM3-SERO ELISA is a 100% sensitive and 100% specific test for the early serodiagnosis of sheep fascioliasis. Preliminary studies in our laboratory seem to indicate that this method may also be useful for the determination of anti–F. hepatica antibodies in serum and milk of other ruminants. A commercial version of MM3-SERO is currently available from BIO X Diagnostics (La Jemelle, Belgium).

The grass shrimp, Palaemonetes pugio, is an important food source for many invertebrate and fish species, including several of commercial importance. The bopyrid Probopyrus pandalicola prevents reproduction in P. pugio by sexual sterilization. The purpose of our research was to determine bopyrid prevalence in grass shrimp over the course of a year. Shrimp were collected from 2 estuarine systems in South Carolina and 2 estuarine systems in Georgia and examined for parasite presence, sex, and gravidity. Site-specific monthly prevalence ranged from 0 to 6.3%. Country Club Creek had the maximum mean ± SE prevalence of 3.1 ± 0.3%, and Harbour Town had the minimum of 1.3 ± 0.3%. Maximum prevalence was concurrent with peak gravidity for Moon River; thus, at this site the negative effect of this parasite on reproductive output may be greater. Reduced egg production may affect grass shrimp abundance and ultimately the recruitment success of its predators.

A survey for Manayunkia speciosa, the freshwater polychaete host for the myxozoan parasite Ceratomyxa shasta, was conducted from 2003 to 2005 as part of an integrated study of the epizootiology of ceratomyxosis in Klamath River salmonids. Substrata samples (n = 257) were collected in a variety of habitats from Klamath Lake to the mouth of the Klamath River to document occurrence and relative abundance of the polychaete by habitat type and to estimate the prevalence of C. shasta within selected polychaete populations. Populations of M. specios a were identified throughout the Klamath River within pools (51.6%), eddy-pools (47.0%), and runs (40.0%). Large populations of M. speciosa were consistently found at the inflow to the main-stem reservoirs where densities were correlated with distance from the inflow into the reservoir. Using polymerase chain reaction assay and composite samples, 12 of 71 populations identified were tested for C. shasta, revealing a mean infection prevalence of 0.27%. An area of elevated infection prevalence (4.9 and 8.3%) was identified with 2 populations below a barrier to salmonid migration, which explains the high infectious spore densities demonstrated in concurrent studies and observations of C. shasta-induced mortality in Klamath River fall Chinook salmon (Oncorhynchus tshawytscha).

Previous studies have described a range of Klossiella species parasitic in marsupial hosts. Klossiella quimrensis is the etiologic agent of renal coccidiosis in the peramelid marsupial hosts Isoodon obesulus and Perameles gunnii in Eastern Australia, but there is no previous report of klossiellosis in Western Australian peramelids. This study describes klossiellosis diagnosed by histology of renal tissue sections collected during necropsy of 20 Perameles bougainville between 2000 and 2005. Sporonts, sporoblasts, and macrogametes were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. The prevalence of renal coccidiosis in P. bougainville diagnosed by renal histology is estimated at 30%. Only a single unsporulated sporocyst was detected by examination of cystocentesis-collected urine, indicating that microscopic evaluation of urine samples is an insensitive diagnostic test for detection of K. quimrensis in P. bougainville. This infection in P. bougainville is indirectly associated with mild multifocal interstitial lymphohistiocytic nephritis and is likely to be only minimally pathogenic in otherwise healthy individuals. Our study also extends the host and geographic range of K. quimrensis to include P. bougainville and Western Australia.

Lemurs on St. Catherines Island, Georgia were tested for Trypanosoma cruzi infection to develop a better understanding of the epizootiology of the parasite in nonhuman primates in the southeastern United States. Fifty-six ring-tailed (Lemur catta), blue-eyed black (Eulemur macaco flavifrons), and black-and-white ruffed (Varecia variegata variegata) lemurs were tested by hemoculture and serology to determine the prevalence of T. cruzi in the population. Of those tested 3 (5%) were identified as culture positive and 25 (44.6%) as seropositive. When hemoculture results were compared with those from a similar study performed in 1997, prevalence remained unchanged. Genetic characterization of the 3 culture isolates indicated they belong to the T. cruzi IIa group, which is identical to strains previously isolated from raccoons on the island. Despite the occurrence of T. cruzi in the population, there was no evidence that the health of the lemurs was compromised as a result of infection. Based upon prevalence and available breeding records we speculate that both vertical and vector-mediated transmission play significant roles in the epidemiology of T. cruzi on the island. This also represents the first report of autochthonous infection in blue-eyed black and black-and-white ruffed lemurs.

Myoglobins (Mbs), globin proteins, are present in high concentrations in trematodes. In Paragonimus westermani, 2 cDNAs were found to encode Mbs. The first clone, Pwmyo1, codes a total of 149 amino acids with a calculated mass of 16.6 kDa. The second, Pwmyo2, encodes a 146–amino acid protein with a calculated mass of 16.2 kDa. The predicted secondary structures showed the presence of 8 helices, which is the basic characteristic of Mbs. Sequence alignment revealed a high homology with the other trematode Mbs. The 2 clones contained the characteristic tyrosyl residues at helical positions B10 and distal E7, which are substitutions that have been previously shown to contribute to the high oxygen affinity of Mbs. Polyclonal antibodies against the recombinant Mbs were raised with no cross-reactivity observed. Immunolocalization revealed the proteins to be distributed generally throughout the parenchymal tissues, but absent from the tegument and reproductive organs. The cell mass of the eggs of the worm stained positive to Pwmyo2 but not Pwmyo1, suggesting the stage-specific expression of these Mbs.

Whirling disease, caused by the myxozoan parasite Myxobolus cerebralis, remains a health threat to salmonid fish in the western United States. Although various aspects of this host–parasite system have been studied, investigations examining the overall epizootiology of whirling disease in an ecosystem are lacking. Therefore, in June 1998, studies were initiated in the Rock Creek watershed of west-central Montana and continued through 2003 to assess the intensity of infection in trout using sentinel cages stationed throughout the drainage. Additional studies determined the percentage of the annelid worm, Tubifex tubifex, releasing M. cerebralis at various localities in Rock Creek and whether there was a seasonal or daily periodicity in the release of the triactinomyxon stage of the parasite from T. tubifex. Lastly, habitat and water quality parameters, and the effects of habitat restoration on transmission of M. cerebralis, were assessed. Overall, the intensity of M. cerebralis infections in sentinel trout increased significantly throughout the drainage between June of 1998 and 2003, with the biggest jump occurring between 1998 and 1999. In addition, the range of M. cerebralis expanded considerably over the period of study. There was no strict correlation between habitat condition and the occurrence of the parasite; fish became heavily infected in optimal and marginal habitats. However, fish exposed at a locality that had the lowest habitat ranking consistently had the highest intensity of infection. The parasite has apparently caused a dramatic decline in rainbow trout densities, but the brown trout population numbers have increased, and the overall fish density remains high. Although a major habitat restoration project did not seem to have an effect on decreasing disease intensity, this was not surprising because the restored area was located just downstream from a “hotspot” of infected T. tubifex.

Oligacanthorhynchus nickoli n. sp. (Acanthocephala: Oligacanthorhynchidae) is described from the great-horned owl, Bubo virginianus (Gmelin, 1788) (type host), and red-tailed hawk, Buteo jamaicensis (Gmelin, 1788), collected in central Arizona. The new species is most similar to Oligacanthorhynchus iheringi and Oligacanthorhynchus minor, but it differs from all congeners primarily by trunk length, proboscis size and armature, egg size, geographical range, and host species. It is distinguished from the 9 Oligacanthorhynchus species occurring in avian hosts from both the Western and Eastern Hemispheres. Descriptions of juvenile forms of O. nickoli from the intestine of B. jamaicensis are provided from recently ingested cystacanths with everted proboscides.

Rhabdias nicaraguensis n. sp. (Rhabditida: Rhabditidae) from the lungs of Norops capito (Sauria: Polychrotidae) is described and illustrated. Rhabdias nicaraguensis n. sp. represents the 54th species assigned to the genus and the 12th from the Neotropical realm. Of the 12 Neotropical Rhabdias species, nicaraguensis is most similar to tobagoensis and vellardi. These 3 species have equatorial placement of the vulva, inflated cuticle, and 6 small circumoral lips. Rhabdias nicaraguensis is easily separated from R. tobagoensis by the shape of the buccal cavity and from R. vellardi by body size and shape of the tail. Rhabdias nicaraguensis differs from both species by host preference, the amount of inflated cuticle covering the body, and the phasmids situated posterior to the midpoint of the tail.

Meiogymnophallus sinonovaculae n. sp. (Digenea: Gymnophallidae) is described from metacercariae found in the razor clam, Sinonovacula constricta, in the Republic of Korea, and adults recovered from the small intestine of experimentally infected mice. The worms are characterized by paired clusters of vitelline follicles, a well-developed pars prostatica with abundant prostate cells, a voluminous undivided seminal vesicle (in adults and metacercariae), and large, grouped, domelike sensory papillae on the ventral surface anterior to the ventral sucker (in metacercariae). This new species resembles the type species Meiogymnophallus affinis, but differs in having compact, elliptical, and 4–5-lobed vitellaria, and an excretory vesicle with bicornuated anterior arms reaching to the oral sucker. This is the second documentation of the presence of a species of Meiogymnophallus in the Republic of Korea.

Larvae of Mesocestoides sp. were recovered in Tenerife (Canary Islands) in 2004 from the peritoneal cavities of 2 domestic dogs and a domestic cat. Morphological and molecular identification were carried out. Mesocestoides litteratus from Vulpes vulpes was sequenced for the first time using the ITS-2 region (18S rDNA), and was included in the phylogenetic analysis to compare the sequence variability among these and other Mesocestoides spp. belonging to different carnivores. Phylogenetic studies were carried out based on maximum parsimony and neighbor-joining analysis. The results showed the relationships between these and other previously published Mesocestoides species. Moreover, it is demonstrated that Mesocestoides sp. from Tenerife comprises a previously unreported sequence. This is the first larval record of Mesocestoides sp. in domestic animals from Tenerife, Canary Islands, Spain.

The anisakid species Contracaecum pelagicum Johnston and Mawson, 1942, is reported for first time at 2 different sites on the Argentine coast (Península Valdés, 42°04′S, 63°38′W and Mar del Plata, 38°05′S, 57°38′W), parasitizing the Magellanic penguin, Spheniscus magellanicus Foster. Morphometric analysis and further studies of adult specimens of C. pelagicum were done using light and scanning electron microscopy. The presence of bifurcated interlabia differentiates the present species from most others in the genus, except (1) from Contracaecum travassosi, which possesses higher interlabia and longer spicules, and a blunt, more constrained tail; (2) from Contracaecum rudolphii, which has longer spicules, blunter spicule tips, postparacloacal papillae with oblique disposition, and a blunter constrained tail; (3) from Contracaecum eudyptulae, which has a blunter tail and longer spicules; and (4) from Contracaecum variegatum, which possesses smaller-diameter, hooklike extensions on auricle lips, and a less robust interlabium with a more marked furrow. In this paper we present the first detailed description of C. pelagicum adults from S. magellanicus. Morphometric data between adult specimens of C. pelagicum from S. magellanicus and those from the black-browed albatross, Diomedea melanophris Temminck, from Argentinean coasts were compared. In addition, fourth-stage larvae that parasitized both hosts were assigned to a nondeterminated Contracaecum species. Ecological parameters for adults and larvae nematodes were calculated.

A new dicrocoeliid trematode, Brachylecithum glareoli n. sp., is described from the biliary ducts of the bank vole, Clethrionomys glareolus, in southwest Poland. This is the first dicrocoeliid species described in rodents from Poland. It is characterized mainly by the maximum body width at the level of the vitellaria; large, longitudinally oval testes; round, or transversely oval, ovary that is smaller than the testes; vitellaria located in the midbody; cirrus sac dorsally overlapping ventral sucker, but never reaching beyond half of its length; and large, distinctly elongated eggs.

Limnomermis steineri n. sp. (Nematoda: Mermithidae) is described from the hemocoel of male, female, and intersex imagos of Ablabesmyia (s. str.) monilis (L.) eclosing from Lake Ozawindib and Lake Alice Bog in northern Minnesota during summers 2000–2005. The species is distinguished from other described members of the genus. Paramermis rosea is returned to Limnomermis. A review of adequately described members of the genus is included. One species of the genus has been reported previously from the Nearctic Realm. Emphasis is placed on the need for host identification, larger number of specimens of both mermithid sexes, and information on the intensity of infections to enable more precise range comparisons in mermithid biometrics.

Two new Rhabdias species are described from the lungs of the cane toad Bufo marinus (L.) from Costa Rica and Nicaragua. Rhabdias alabialis n. sp. differs from other known species of the genus by the remarkable morphology of its head end, i.e., the absence of lips or pseudolabia, the slitlike oral opening, and the triangular shape of the buccal capsule in apical view. Rhabdias pseudosphaerocephala n. sp. is identified as a form previously known in Central and South America as Rhabdias sphaerocephala Goodey, 1924, a species initially described from toads in Europe. The new species is differentiated from R. sphaerocephala based on head-end morphology and sequences of nuclear rDNA.

Megachona chamelensis n. gen., n. sp. is described from the intestinal cecae of blue striped chub Sectator ocyurus (Kyphosidae, Perciformes), from Chamela Bay, Mexico. Megachona n. gen. most closely resembles Beaninema Caspeta-Mandujano, Moravec, and Salgado-Maldonado, 2001; Fellicola Petter and Køie, 1993; and Rhabdochona Railliet, 1916. The main characters that distinguish the new genus from all other rhabdochonids include a longer than wide funnel-shaped prostom and cuticular longitudinal ridges of prostom forming anteriorly subterminal massive toothlike structures followed posteriorly by irregularly arranged smaller teeth. This finding brings the total number of genera of Rhabdochonidae of marine fish in Mexico to 2. The new species is characterized by having a smaller number of cuticular longitudinal ridges in the male prostom than in the female prostom, forming massive toothlike structures in its subterminal portion, followed by more minute teeth in the female than in the male, a slender tail end with a broad tip, the distal part of the left spicule with a lanceolate end, a straight right spicule without a dorsal barb, 1 pair of precloacal and 3 pairs of postcloacal papillae, and a smooth egg surface.

Two new nematode species, Philometra gymnosardae n. sp. (Philometridae) and Heptochona maldivensis n. sp. (Rhabdochonidae), are described from the dogtooth tuna Gymnosarda unicolor (Rüppell) (Scombridae, Perciformes) from the Indian Ocean off the Maldive Islands (Republic of Maldives). The former species is characterized mainly by unequal, conspicuously long (859 and 435 μm) spicules; the structure of the caudal end in the male (found in the host's stomach); by markedly large, oval cephalic papillae (n = 8) of the outer circle; the presence of a small, anterior bulb on the very long esophagus; and 2 large caudal projections in the gravid female (parasitic in the host's body cavity). This is the first-known species of Philometra whose gravid females are present in the body cavity of tuna fishes. Heptochona maldivensis resembles H. stromatei but differs mainly in the position of deirids, shape of the muscular esophagus, character of postanal papillae, length of the left spicule (648 μm), much larger body measurements, location in the host (stomach), and the host type. Rhabdochona parastromatei Bilqees, 1971, is synonymized with H. stromatei, whereas Heptochona sindica Akram and Pie de Imprenta, 1988, and H. rivdica Akram, 1988, are invalid names. Heptochona varmai is transferred to another genus as Rhabdochona varmai (Gupta and Masoodi, 1990) n. comb. Rhabdochona varmai, Heptochona schmidtii Arya, 1991, and Rhabdochona marina Lakshmi and Sudha, 1999, are considered species inquirendae.

This study describes a new species of Pomphorhynchus collected from Percilia gillissi Girard, 1855 from the Zañartu canal, between the sister basins of the Itata and Laja rivers, in central Chile. Pomphorhynchus moyanoi n. sp. is characterized by an asymmetrical, well-differentiated subspherical bulb and 12–14 longitudinal rows of 13–14 hooks; the third and the fourth hook in each row are stout. Among South American species, P. moyanoi n. sp. shows some similarities to the Chilean species P. yamagutii Schmidt & Hugghins, 1973, but it differs in having a longer neck, larger bulb, and different proboscis armature arrangement. Pomphorhynchus moyanoi n. sp. differs from P. patagonicus Ortubay, Ubeda, Semenas & Kennedy 1991, in the bulb shape (protuberances), number of rows, fourth hook size and basal hook size. Pomphorhynchus moyanoi n. sp. also differs from P. sphaericus in the arrangement of hooks (number of rows and hooks per row), length and width of the proboscis, neck width, and symmetry of the bulb.

Austrobdella coliumicus n. sp. is described from Coliumo Bay, Chile. It is characterized by a continuous, external coelomic canal (=marginal lacuna), 5 pairs of testisacs, accessory gland cells, a body not distinctly divided into trachelosome and urosome, 2 pairs of dorsal ocelli on the trachelosome, dorsal and ventral segmental ocelli present on the urosome, green overall pigmentation with transverse brown bands, and the absence of conducting tissue. Austrobdella coliumicus is distinguished from other species of Austrobdella by the presence of 2 pairs of ocelli on the trachelosome and a more cylindrical body. It is unusual that this leech was collected from inside the mantle cavity of the razor clam, Ensis macha. Austrobdella losmoliniensis n. sp. is described from the electric ray, Discopyge tschudii, collected at Los Molinos, Chile. It is characterized by a continuous, external coelomic canal; 5 pairs of testisacs; accessory gland cells; a body distinctly divided into trachelosome and urosome; 1 pair of eyes on the oral sucker; overall black pigmentation with unpigmented areas; and the absence of conducting tissue. Austrobdella losmoliniensis can be distinguished from other species of Austrobdella by the combination of 1 pair of eyes on the oral sucker and black pigmentation.

Balb/cJ mice fail to mount an immune response capable of clearing infection with larval Taenia crassiceps. Additionally, male Balb/cJ mice display a lag in larval growth of approximately 3 wk as compared to growth in female mice. It has been reported that male Balb/ cAnN mice generate a protective immune response early in infection, and become permissive to larval growth after they feminize (200-fold increase in serum estradiol and 90% decrease in serum testosterone). To determine if a different strain of Balb/c mice (Balb/cJ) also feminize, serum was collected from infected male mice for 16 wk and levels of 17-β-estradiol and testosterone were measured via ELISA. In addition, the mounting responses of 12- and 16-wk infected male mice, as well as uninfected control mice, were determined after isolation with a female mouse. The results of these experiments show that male Balb/cJ mice do not feminize during infection with larval T. crassiceps. There was no significant change in serum levels of either 17-β-estradiol or testosterone during the course of infection (>16 wk). Moreover, there was no significant decrease in the number of times infected male mice mounted the female mouse as compared to uninfected controls. These results suggest that there may be variances between the substrains of Balb/c mice that lead to the phenotypic differences reported for male Balb/cJ and Balb/cAnN mice.

Species of Allocreadiidae are an important component of the parasite fauna of freshwater vertebrates, particularly fishes, and yet their systematic relationships with other trematodes have not been clarified. Partial sequences of the 18S and 28S ribosomal RNA genes from 3 representative species of Allocreadiidae, i.e., Crepidostomum cooperi, Bunodera mediovitellata, and Polylekithum ictaluri, and from 79 other taxa representing 78 families of trematodes obtained from GenBank, were used in a phylogenetic analysis to address the relationships of Allocreadiidae with other plagiorchiiforms/plagiorchiidans. Maximum parsimony and Bayesian analyses of combined 18S and 28S rRNA gene sequence data place 2 of the allocreadiids, Crepidostomum cooperi and Bunodera mediovitellata, in a clade with species of Callodistomidae and Gorgoderidae, which, in turn is sister to a clade containing Polylekithum ictaluri and representatives of Encyclometridae, Dicrocoelidae, and Orchipedidae, a grouping supported by high bootstrap values. These results suggest that Polylekithum ictaluri is not an allocreadiid, a conclusion that is supported by reported differences between its cercaria and that of other allocreadiids. Although details of the life cycle of callodistomids, the sister taxon to Allocreadiidae, remain unknown, the relationship of Allocreadiidae and Gorgoderidae is consistent with their larval development in bivalve, rather than gastropod, molluscs, and with their host relationships (predominantly freshwater vertebrates). The results also indicate that, whereas Allocreadiidae is not a basal taxon, it is not included within the suborder Plagiorchiata. No support was found for a direct relationship between allocreadiids and opecoelids either.

In an attempt to identify parasite surface components involved in the interaction with the host cell, the present research focuses on the rafts of Eimeria tenella that might be involved in the host cell invasion process. To that end, this study was undertaken to investigate the expression of flotillin-1, which is an important component and marker of lipid rafts at the plasma membrane of sporozoites of E. tenella. The expression of this plasma membrane protein was identified by an antibody that specifically reacts with flotillin-1 and was studied by electron microscopy. Flotillin-1 was found to occur in patches on the surface of E. tenella sporozoites. Immunoblot analysis of the total proteins of the sporozoites showed only 1 band of approximately 48 kDa. This indicates that the antibody exclusively recognized the molecules of flotillin-1 expressed on the surface of E. tenella sporozoites. The presence of flotillin-1 on the cellular membrane of sporozoites predominantly at the apical tip suggests that flotillin-1 belongs to the invasion machinery of E. tenella.

Species of Cryptosporidium and Giardia can infect humans and wildlife and have the potential to be transmitted between these 2 groups; yet, very little is known about these protozoans in marine wildlife. Feces of river otters (Lontra canadensis), a common marine wildlife species in the Puget Sound Georgia Basin, were examined for species of Cryptosporidium and Giardia to determine their role in the epidemiology of these pathogens. Using ZnSO₄ flotation and immunomagnetic separation, followed by direct immunofluorescent antibody detection (IMS/DFA), we identified Cryptosporidium sp. oocysts in 9 fecal samples from 6 locations and Giardia sp. cysts in 11 fecal samples from 7 locations. The putative risk factors of proximate human population and degree of anthropogenic shoreline modification were not associated with the detection of Cryptosporidium or Giardia spp. in river otter feces. Amplification of DNA from the IMS/DFA slide scrapings was successful for 1 sample containing >500 Cryptosporidium sp. oocysts. Sequences from the Cryptosporidium 18S rRNA and the COWP loci were most similar to the ferret Cryptosporidium sp. genotype. River otters could serve as reservoirs for Cryptosporidium and Giardia species in marine ecosystems. More work is needed to better understand the zoonotic potential of the genotypes they carry as well as their implications for river otter health.

We examined the role that predation of infected conspecific fish and postcyclic transmission might play in the life cycle of the Asian fish tapeworm, Bothriocephalus acheilognathi (Cestoda: Pseudophyllidea) Yamaguti, 1934. Young-of-the-year (YOY) bonytail chub (Gila elegans) were exposed to copepods infected with B. acheilognathi and subsequently fed to subadult bonytail chub. Within 1 wk after consumption of the YOY chub, subadults were necropsied and found infected with gravid and nongravid tapeworms. This study provides evidence that postcyclic transfer of B. acheilognathi can occur. Postcyclic transmission may be an important life history trait of B. acheilognathi that merits consideration when studying the impact and distribution of this invasive and potentially pathogenic tapeworm.

Forty-eight scaled quail (Callipepla squamata) were collected during August 2002 at Elephant Mountain Wildlife Management Area in Brewster County, Texas, and examined for helminths. Eight species of helminths were found (5 nematodes and 3 cestodes), representing 2,811 individuals. Of these species, Gongylonema sp., Procyrnea pileata, and Choanotaenia infundibulum are reported from scaled quail for the first time. Prevalence of Aulonocephalus pennula, Gongylonema sp., Oxyspirura petrowi, Physaloptera sp., P. pileata, C. infundibulum, Fuhrmannetta sp., and Rhabdometra odiosa was 98, 2, 56, 4, 60, 2, 25, and 35%, respectively. Aulonocephalus pennula numerically dominated, accounting for 88% of total worms. Statistical analyses were performed on the 5 species with ≥25% prevalence using the after-hatch-year host sample (n = 38). Prevalence of P. pileata was higher (P = 0.049) in females than in males and higher (P = 0.037) in the sample collected from the site that had spreader dams (berms 1–2 m high and 4–55 m long constructed in varying sizes to catch and retain rainfall) than the control site (no spreader dams). Higher rank mean abundance of A. pennula and O. petrowi (P = 0.0001 and P = 0.0052, respectively) was found in the host sample collected from the site that had spreader dams than the control site. A host gender-by-collection site interaction (P = 0.0215) was observed for P. pileata. Findings indicate that scaled quail are acquiring indirect life cycle helminths in arid western Texas habitats.

In the present study, we investigated the effects of protease pretreatments of host erythrocytes (RBC) on the in vitro growth of bovine Babesia parasites (Babesia bovis and B. bigemina) and equine Babesia parasites (B. equi and B. caballi). The selected proteases, trypsin and chymotrypsin, clearly modified several membrane proteins of both bovine and equine RBC, as demonstrated by SDS-PAGE analysis; however, the protease treatments also modified the sialic acid content exclusively in bovine RBC, as demonstrated by lectin blot analysis. An in vitro growth assay using the protease-treated RBC showed that the trypsin-treated bovine RBC, but not the chymotrypsin-treated ones, significantly reduced the growth of B. bovis and B. bigemina as compared to the control. In contrast, the growth of B. equi and B. caballi was not affected by any of these proteases. Thus, the bovine, but not the equine, Babesia parasites require the trypsin-sensitive membrane (sialoglyco) proteins to infect the RBC.

The purpose of this study was to determine how the gastrointestinal helminthofauna varies according to the age and sex of the lizard, Enyalius perditus, captured in Ibitipoca State Park in the state of Minas Gerais, Brazil, and to discuss the ecological and behavioral significance of these relationships. Fifty-five specimens of E. perditus were captured in drop traps, then killed, necropsied, and examined for the presence of helminths in the gastrointestinal tract. Nematodes, including Strongyluris oscari, Oswaldocruzia subauricularis, and Aplectana vellardi, were found. This was the first record of the last-named species in reptiles, and the first record of the first 2 species in E. perditus. The number of helminths increased with snout-vent length and, therefore, age of the lizards. Male E. perditus lizards were more heavily infected by nematodes than females; the largest numbers of nematodes occurred in the caecum and large intestine.

Biomphalaria glabrata snails injected with extracts of Schistosoma mansoni miracidia, mother sporocyst excretory–secretory product, cercariae, and adults, showed increased mitotic activity in histological sections of the amebocyte-producing organ (APO) relative to water-injected controls. The mitotic response was generally higher to extracts adjusted to 1.0 mg protein/ml than to a 10-fold lower concentration, although in most cases this increase was not statistically significant. Colchicine treatment prior to fixation significantly increased the number of mitotic figures in APOs of all groups of extract-injected snails, both with respect to water-injected controls and, with 1 exception, relative to matched colchicine-untreated snails. Extracts of adult worms elicited a pronounced mitotic response, suggesting that adults may share a mitogenic molecule with larvae. The high variability in counts of mitotic figures may limit the usefulness of this histological method.

Most efforts aimed at elucidating the factors responsible for the variation in species richness among different parasite communities have focused on host characteristics such as body mass or diet. Independently of host features, however, the way in which parasites use resources within the host may also affect the species richness of the community. The distribution of parasite individuals or biomass in niche space determines whether host resources are used evenly, or whether there are gaps in resource use, with some parts of the total niche being underutilized. Here, the concepts of functional richness and functional evenness are applied to parasite communities for the first time, using simple indices. Measurements of the distribution of species in niche space within communities, such as mapping the distribution of helminths along the length of the host's intestine, is standard practice in parasitology. In such cases, functional richness is simply the proportion of the total number of intestine sections available that are used by at least 1 worm, whereas functional evenness measures the evenness in the distribution of worm numbers or biomass across all niche sections that are occupied. Data on cestode communities of elasmobranchs are used to illustrate the use of these indices, and to show how important they can be in tests of ecological hypotheses. The indices presented here capture essential features of resource use in parasite communities, and can be useful tools for comparative analyses.