Data on the representatives of the nematode family Rhabdiasidae in the Nearctic are summarized from the literature, study of new material, and examination of museum specimens. A description of Rhabdias tarichae sp. nov. and redescriptions of Rhabdias joaquinensis, Rhabdias ambystomae, Rhabdias ranae, and Rhabdias americanus are given. New host and geographical records are provided for several Rhabdias species. Rhabdias sp., probably representing another species new to science, was found among museum specimens from the California newt Taricha torosa; however, the poor state of the specimens did not permit description. Keys for determination of Nearctic Rhabdias species are provided, and the applicability of some morphological characters for differentiation of Rhabdias species is discussed.

Fecal samples from 450 cats were examined by fecal floatation to determine the helminth fauna of Connecticut cats. Overall, 39.8% of the cats were infected with the roundworm Toxocara cati, 4.7% with the tapeworm Dipylidium caninum, 0.4% with the hookworm Ancylostoma tubaeforme, and 0.2% with the lungworm Aelurostrongylus abstrusus. Toxoplasma-like oocysts were found in the feces of 0.7% of the cats. Sheltered cats had a significantly higher prevalence (67.5%) of T. cati infection than did client-owned cats (30.4%). All intestinal helminths detected in this study have zoonotic potential, underscoring the importance of the domestic cat as a reservoir for zoonotic parasites. Strict adherence by veterinarians to the guidelines of the Centers for Disease Control and Prevention and the American Association of Veterinary Parasitologists for strategic deworming of kittens is warranted, as is vigilance in the control of feral cats and in the screening and treatment of kittens and cats ``going out” for adoption from shelters.

Actinobdella inequiannulata was found on the white sucker, Catostomus commersoni, and less frequently on the longnose sucker, Catostomus catostomus, in Algonquin Provincial Park, Ontario, Canada. Catostomus commersoni parasitized with Act. inequiannulata was collected from July to October 1973 and May to October 1974. In May and October, less than 3% of the fish carried leeches. In July, 80% of the fish were parasitized with an average of 1.5 leeches/fish. Observations on leech weight suggest that young leeches attach to fish from May to September, some mature in July, and a second generation of leeches reparasitize the fish in August and September. The mean size of leeches on suckers increased from May until July, after which the size remained relatively constant. Leeches produced characteristic lesions on the opercula of suckers. Fully developed lesions on fish opercula produced by aggregated leeches had varying amounts of central erosion, extravasation, dermal and epidermal hyperplasia, and necrosis.

Enterobius (Colobenterobius) serratus sp. nov. (Nematoda: Oxyuridae) is described from females collected from a proboscis monkey, Nasalis larvatus (Primates: Cercopithecidae: Colobinae), in Sarawak, Borneo, Malaysia. This species is readily distinguished from other members of the subgenus by the serrated inner margins of lips, lamellated superstructures of the esophageal teeth forming denticles, larger body, and larger eggs.

The occurrence of Trichodina domerguei on the round goby, Neogobius melanostomus, was studied from October 1999 through September 2000. Overall prevalence and mean intensity levels were recorded as 77.9% and 156 ± 43.7 Trichodina per infested fish, respectively. Average host length was 71.1 ± 2.2 mm. Statistically significant differences of parasite prevalence and intensity in relation to season and length of fish were observed. Seasonal variations were also observed in the dimensions of T. domerguei. Neogobius melanostomus is a new host recorded for T. domerguei. This is the first ecological study of T. domerguei conducted in an alternately brackish and freshwater environment.

The generic diagnosis of Pavanelliella (Monogenoidea: Dactylogyridae) is emended to include species with rounded, cephalic margins and well-developed haptors set off from the trunk by a peduncle. Pavanelliella scaphiocotylus sp. nov. is described from the nasal cavity of the Guatemalan chulin, Rhamdia guatemalensis (Heptapteridae), from Ixin-há Cenote, Yucatán, Mexico. The new species differs from its congener, Pavanelliella pavanellii, in possessing a well-developed haptor and peduncle, a coiled male copulatory organ comprising 5–6 counterclockwise rings, and a vaginal canal with 4–5 loops.

Ten species of endohelminths including 2 cestodes, 3 nematodes, and 5 trematodes were collected from 6 American white pelicans, Pelecanus erythrorhynchus, and 22 species of endohelminths including 2 acanthocephalans, 3 cestodes, 4 nematodes, and 13 trematodes were collected from 10 brown pelicans, Pelecanus occidentalis, from the Galveston, Texas, area. A mean of 120 and a range of 4 to 2,134 helminths were present in the American white pelican, and a mean of 57 and a range of 2 to 10,413 helminths were found in the brown pelican. Two cestodes, 3 nematodes, and 3 trematodes were common to both species of pelicans. Parvitaenia ibisae, Tetrabothrius sp., Capillaria sp. represent new host records for the American white pelican, and Echinochasmus cf. donaldsoni, Phagicola macrostoma, and Lyperosomum sp. represent new host records for the brown pelican. Hypotheses for the recent infection of pelicans with species of Bursacetabulus and Bursatintinnabulus along the Gulf coast are discussed.

Eighteen species of helminth were collected from 2 species of charadriid from Namibia. The resident white-fronted plover, Charadrius marginatus, (n = 40) and the migrant ruddy turnstone, Arenaria interpres, (n = 40) had 10 species each. Similarity indices between the 2 host species were low, and the only helminth species shared were 2 species of microphallid trematode, Levinseniella propinqua and Maritrema eroliae. Cestode species were dominant (12), followed by trematode species (8). No acanthocephalans or nematodes were collected. Helminths were significantly more abundant in the resident Cha. marginatus than in the migrant Ar. interpres, but there was no significant difference in species richness. Sixteen of the 18 species of helminth were generalists. The trematode guild had the highest percentage of total abundance in both host species. Most species of helminth were found in great abundance in specific sections of the gastrointestinal tract. There was no significant difference in total abundance and species richness for helminths between 2 collecting sites 20 km apart for either Cha. marginatus or Ar. interpres. There were marked differences in abundance for some helminth species between sites for the resident Cha. marginatus but much less for the migrant Ar. interpres. These results further substantiated that Cha. marginatus demonstrated site fidelity and Ar. interpres did not.

Twenty-six coyotes (Canis latrans) collected in Florida, U.S.A., were examined for parasites. Nine species of helminths (1 trematode, 1 cestode, 6 nematodes, and 1 acanthocephalan), 1 species of biting louse, and 2 species of ticks were identified. Dirofilaria immitis (43%), Ancylostoma caninum (33%), Physaloptera rara (29%), and Taenia pisiformis (24%) were the most prevalent helminths. Macracanthorhynchus ingens is reported from coyotes for the first time, and Spirocerca lupi is reported in coyotes from Florida for the first time. Ectoparasites collected included the biting louse Trichodectes canis and the ticks Amblyomma maculatum and Dermacentor variabilis. A coyote infected with 66 Di. immitis had evidence of chronic pulmonary arteritis and medial hypertrophy of pulmonary aterioles.

Ova of Diphyllobothrium sp. were found in 7 of the 29 coprolites examined from 4 sites within the Chiribaya archaeological zone near Ilo, southern Peru. The Chiribaya represent a pre-Inca civilization of the Middle Horizon (600–1000 A.D.) and the Late Intermediate Period (1000–1476 A.D.). The Chiribaya economy was based on agriculture, animal husbandry, and maritime resources. The apparent commonality of diphyllobothriasis is supportive of the important role that fish played in the diet of the Chiribaya. Free-living coprophagous nematodes were found in 2 of the 29 samples.

The comparative parasitology of endemic, primarily fossorial squamate reptiles of xeric habitats in Florida, U.S.A., is described, largely based on live-trapping studies in Ocala National Forest, Marion County, Florida, from 1992 through 1998. Nineteen new host records (*) are reported, and a new species of Isospora is described. Neoseps reynoldsi (Scincidae) is host to Eimeria egregia*, Isospora neosepsorum n. sp.*, probably 2 species of Hartmannella, Parapharyngodon ocalaensis, and Eutrombicula* sp.; Eumeces egregius onocrepis (Scincidae) is parasitized by Proteromonas lacertaeviridis*, Monocercomonas colubrorum*, Retortamonas saurarum, E. egregia, Hartmannella spp.*, P. ocalaensis*, and Eutrombicula* sp.; Tantilla relicta relicta (Colubridae) is host to P. lacertaeviridis*, M. colubrorum*, R. saurarum*, Hartmannella spp., Eimeria pleistocenensis, E. amphorae, Eimeria sp., Isospora wilsoni, Caryospora tantillae, C. relictae, Kalicephalus inermis*, and P. ocalaensis*; Sceloporus woodi (Phrynosomatidae) is parasitized by M. colubrorum*, P. lacertaeviridis, R. saurarum*, a possible Hexamastix species, and Eutrombicula* sp.; Rhineura floridana (Amphisbaenidae) is the host of Paradollfusnema telfordi. Other saurian species examined, not endemic to the sandhills community, were Cnemidophorus sexlineatus (Teiidae), host to P. lacertaeviridis, M. colubrorum, R. saurarum, larval Physaloptera sp., and Eutrombicula* sp., and Scincella lateralis (Scincidae), parasitized by Eimeria scincellae, Hartmannella spp.*, and a cestode, Bitegmen sp.*

Forty-five adult burbot, Lota lota, collected in July 1998 from Six Fathom Bank (Six Fathom Bank Lake Trout Refuge) and Yankee Reef in Lake Huron, Michigan, U.S.A., were examined for parasites. A total of 10 parasite species infected burbot. Diplostomum sp., Eubothrium rugosum, Haplonema hamulatum, Echinorhynchus salmonis, and Trichodina sp. infected 60% or more of the burbot examined from each location. Diplostomum sp. had the highest mean intensity, and E. salmonis had the highest mean abundance in burbot from Six Fathom Bank. Echinorhynchus salmonis had the highest mean intensity and mean abundance in burbot from Yankee Reef. Diplostomum sp., H. hamulatun, and E. salmonis in burbot from Yankee Reef had significantly higher mean intensities and mean abundances than those in fish from Six Fathom Bank. The lengths and weights of burbot from Yankee Reef were significantly greater than those of fish from Six Fathom Bank. A checklist of parasites of burbot from published records in North America is presented.

Gregarines are parasites common in insects, especially in culture. No effective chemotherapeutic or chemoprophylactic control protocol exists, but sulfadimethoxine has targeted effects on sporozoites and trophozoites. Efficacies of metronidazole and potassium sorbate were independently administered in 5-d regimens to evaluate their efficacy as chemotherapeutic agents against 2 gregarine species, Gregarina cubensis and Protomagalhaensia granulosae, infecting Death's Head Cockroaches, Blaberus discoidalis. Relative to the control, metronidazole significantly reduced intensities of both G. cubensis and P. granulosae but did not significantly reduce gametocyst production. Potassium sorbate had no effect on gregarine intensities but significantly increased the rate of gametocyst production. These results eliminate potassium sorbate as a chemotherapeutic agent in this system but suggest that metronidazole has promise as a gregarine control agent in arthropod monoculture.

We investigated the endo- and ectoparasitic fauna of 45 specimens of Rattus rattus and 44 specimens of Mus musculus collected in Sicily. This study is the second survey of the parasitic fauna of these 2 rodent species on this Mediterranean island. Four nematode species, 1 cestode species, 2 flea species, and 1 tick species were recovered from R. rattus. Six nematode species, 3 cestode species, 1 digenean species, 1 flea species, and 1 tick species were recovered from M. musculus. As noted on other western Mediterranean islands, both rodent species show a depauperate parasite species richness in comparison with continental situations.

The prevalence of eastern mosquitofish (Gambusia holbrooki) infected with larvae of Eustrongylides ignotus declined during an 8-yr period from 54% in 1990 to 0% during the last year at a site near a sewage inflow into a watershed in north-central Florida, U.S.A. Treated human sewage had been discharged into this watershed for about 68 yr, but this practice was discontinued in the fifth year of our study. During the last 3 yr of the study, samples of mosquitofish, oligochaetes, water, and sediment were examined in detail from this site plus 3 other sites along the watershed. The density of aquatic oligochaetes was greater at the site near the historic sewage inflow than at other sites and did not change significantly during the later part of the study. Initially, dissolved oxygen (DO) in the water column was lower at the site of the historic sewage inflow than at other sites, whereas mean sediment, total nitrogen, total carbon, and total phosphorous were greater. Dissolved oxygen increased and the other parameters declined after sewage input was terminated and coincided with a decline in numbers of infected fish. Although other factors, such as human disturbance and changes in wading bird foraging patterns, may have contributed to variations in the prevalence of infected fish, we conclude that discharge of sewage effluent into wading bird foraging areas may result in increased prevalences of fish infected with eustrongylid larvae.

During July 1999, 172 crabs from Ubatuba Bay, São Paulo, Brazil, were examined from 4 families as follows: Portunidae, Arenaeus cribrarius, Callinectes danae, Callinectes ornatus, Charybdis hellerii, Portunus spinimanus, and Portunus spinicarpus; Calappidae, Hepatus pudibundus; Majidae, Libinia ferreirae; Leucosiidae, Persephona mediterranea and Persephona lichtensteinii. One cephaline gregarine symbiont was found in the hindgut of a specimen of Cal. ornatus, and no positively identified, internal and multicelled symbionts were detected. Twenty-one specimens (14.3%) from 7 of the 10 species (all except H. pudibundus, P. mediterranea, and P. lichtensteinii) carried the nemertean worm, Carcinonemertes carcinophila ct. imminuta in either their egg masses or gills. This is the first report of this epibiont from the Ubatuba region. Two specimens of an undescribed polychaete worm were found in the gill of a specimen of L. ferreirae. A stalked barnacle, Octolasmis lowei, was found on the gills of 11 crabs (7.5%). Only 3 crab species (36.6% of Cal. danae, 9.0% of Cal. ornatus, and 7.7% of Po. spinimanus) carried the typical barnacle, Chelonibia patula, on their dorsal carapaces. The percentage of individuals of Cal. danae and Cal. ornatus hosting barnacles (prevalence) as well as the number of barnacles on individual crabs was positively correlated with crab size.

One hundred and three newts (Notophthalmus viridescens) collected in 2001 from 118th Pond, Allegan County, Michigan, U.S.A., were examined for parasites. Four helminth taxa (Megalodiscus temperatus, an undetermined metacercaria, Falcaustra sp., Spiroxys sp.) infected these newts. Falcaustra sp. was the most prevalent, intense and abundant species. The prevalence of Spiroxys sp. was second only to Falcaustra sp. The prevalence of no helminth taxon exceeded 15.5%, and no helminth was gravid. Thirty-three (32%) newts were infected with 1 helminth species, and 7 (7%) harbored 2 helminth species. In August 2000, gorgoderid metacercariae infected 2 of 6 (33%) newts examined. The helminth fauna of newts from 118th Pond is not host specific because these 5 helminth species also infected green frogs in an earlier study from this pond.