Coccidian Parasites (Apicomplexa: Eimeriidae) of Arkansas Herpetofauna: A Summary with Two New State Records.

Coccidian parasites (Protista: Apicomplexa: Eimeriidae) commonly infect reptiles, and to a lesser degree, amphibians. The family Eimeriidae includes at least 18 genera and 3 of them, Caryospora, Eimeria, and Isospora have been reported previously from various Arkansas herpetofauna. Over the past 3 decades, our community collaborative effort has provided a great deal of information on these parasites found in amphibians and reptiles of Arkansas. Here, we provide a summary of all coccidians reported from herptiles of the state as well as provide 2 new state records for coccidians from non-native Mediterranean geckos, Hemidactylus turcicus.

Coccidia (Apicomplexa: Eimeriidae) of Three-toed Box Turtles, Terrapene carolina triunguis (Reptilia: Testudines), from Arkansas and Oklahoma.

We collected 50 three-toed box turtles (Terrapene carolina triunguis) from 9 counties of Arkansas and 4 counties of Oklahoma, and examined their feces for coccidial parasites. Nine of 24 (38%) turtles from Arkansas and 8 of 26 (31%) from Oklahoma were found to be passing oocysts of Eimeria ornata. This represents two new geographic distributional records for this coccidian. Measurements of individual isolates of E. ornata as well as morphological characteristics are provided with comparison to its original description and to another Terrapene coccidian, Eimeria carri. In addition, we noted an adelid pseudoparasite being passed by a single T. c. triunguis from Oklahoma that likely represents a parasite of arthropods.

Digenean trematode infections of native freshwater snails and invasive Potamopyrgus antipodarum in the Grand Teton National Park/John D. Rockefeller Memorial Parkway Area.

Outside its native range, the invasive New Zealand mud snail (NZMS), Potamopyrgus antipodarum, is rarely reported to harbor parasites. To test this observation, 7 sites along the Snake River and Polecat Creek in the Grand Teton National Park/John D Rockefeller Memorial Parkway area (Wyoming) were surveyed for native aquatic snails, NZMS, and associated digenean trematodes, in July 2005. At 6 sites, native snails harbored patent digenean infections; within 2 hr, < or =10% of lymnaeid snails shed furcocercariae or xiphidiocercariae, and < or =42% of physid snails released furcocercariae or echinostome cercariae. Partial 18S rDNA sequences were recovered from several furcocercariae. Potamopyrgus antipodarum was present at, and collected from, 5 sites. Polymerase chain reaction assays targeting digenean rDNA sequences in DNA extracted from pools of 150 NZMS snails did not detect parasites. The examination of 960 NZMS by overnight shedding yielded 1 occurrence of (surface-encysted) metacercariae of an unclassified notocotylid (based on 18S and 28S rDNA sequences). The dissection of 150 ethanol-fixed NZMS (30/site) revealed 2 types of digenean metacercariae encysted in tissues of 5 snails from Polecat Creek. Thus, invasive NZMS may serve as first and second intermediate host for digenean parasites.

Eimeria spp. (Apicomplexa: Eimeriidae) from the eastern chipmunk (Tamias striatus) in Pennsylvania with a description of one new species.

Intestinal contents of 41 eastern chipmunks (Tamias striatus) from Armstrong County, Pennsylvania, were examined for the presence of Eimeria spp. Three previously named species were identified: E. lateralis (prevalence = 9%), E. ovata (3%), and E. vilasi (74%); 1 new species, Eimeria tamiensis n. sp. (74%), is described here. This report extends the geographic ranges of the named species into Pennsylvania. Sporulated oocysts of E. tamiensis n. sp. are ovoid and 18.6 x 14.5 (16-23 x 12-17) microm, with no micropyle or residuum. Sporocysts are ellipsoid and 8.6 x 5.4 (7-10 x 4-8) microm. with a Stieda body and granular residuum. Prevalences of E. lateralis and E. vilasi were similar to those reported previously. The differences in prevalences may be due to different life-history strategies of high- and low-prevalence Eimeria species.

Eimeria spp. (Apicomplexa: Eimeriidae) from black- and white-tailed prairie dogs (Cynomys ludovicianus and Cynomys leucurus) in central and southeast Wyoming.

Feces collected from live-trapped black- (Cynomys ludovicianus) and white-tailed prairie dogs (Cynomys leucurus) from central and southeastern Wyoming were examined to determine the presence and prevalence of eimerian species. Six species (Eimeria adaensis [black-tailed prairie dog prevalence = 33%, white-tailed prairie dog prevalence = 51%], Eimeria beecheyi [8%, 28%], Eimeria callosper-mophili [64%, 71%], Eimeria lateralis [3%, 7%], Eimeria morainensis [19%, 8%], and Eimeria spermophili [2%, 1%]) were identified from both host species. Eimeria pseudospermophili was found infecting only black-tailed (prevalence = 1%) and Eimeria bilamellata only in white-tailed prairie dogs (2%). Reinfections in individual hosts were observed with E. callospermophili and E. adaensis. Comparison of these results with the published literature suggests that the host genera Cynomys and Spermophilus share a common guild of eimerians and that members of this guild have a long evolutionary association with these hosts, or host switching, or both, is common between these groups.

Nongastrointestinal helminths in marten (Martes americana) from Ontario, Canada.

Six species of nongastrointestinal nematodes were recovered from 405 marten, (Martes americana), examined from six areas in Ontario, Canada in 1992 to 1993. Three species (Crenosoma petrowi, Eucoleus aerophilus, Filaroides martis) were found in the respiratory tract, one in the urinary bladder (Pearsonema plica), one in the kidney (Dioctophyme renale), and one in the musculature (Trichinella sp. larvae). This is the first report of F. martis and P. plica from this host. In addition a specimen of Dracunculus insignis collected from a marten pelt was received. Based on our results, martens are primary definitive hosts for few nongastrointestinal nematodes. Animals in more southern areas had greater species richness than those from higher latitudes.

Synonymy of Eimeria larimerensis with Eimeria lateralis.

Oocysts of Eimeria lateralis were isolated from feces of Spermophilus richardsonii and compared to published descriptions of E. lateralis and Eimeria larimerensis from other spermophiline rodent hosts. A comparison from other spermophiline rodent hosts. A comparison of these 2 eimerian species, combined with an examination of host specificity of spermophiline eimerians and host and parasite distributions, suggests that E. larimerensis is synonymous with E. lateralis.

Eimerian guilds (Apicomplexa: Eimeriidae) in Richardson's (Spermophilus richardsonii) and Wyoming (Spermophilus elegans) ground squirrels.

Feces of Richardson's ground squirrels (Spermophilus richardsonii) were examined to determine occurrence and prevalence of eimerian species and to compare guilds in these hosts to previously described guilds from Wyoming ground squirrels (Spermophilus elegans). Six species of Eimeria were collected from 100 Richardson's ground squirrels: Eimeria beecheyi (36% infected); Eimeria bilamellata (13%); Eimeria callospermophili-Eimeria morainensis complex (41%); Eimeria lateralis (6%); and Eimeria spermophili (9%). The species composition and prevalences were essentially identical in the 2 congeneric hosts. Three species were consistently more (> 30%) and 3 were consistently less (< 20%) prevalent in both host species. Furthermore, in both squirrel species the rare species were more prevalent in juveniles. Eimerian guilds such as these may be common to many species of ground-dwelling sciurid squirrels. The report of E. beecheyi in Richardson's ground squirrel constitutes a new host record for this species.

Effects of eimerian (Apicomplexa: Eimeriidae) infections on nutrient assimilation in the Wyoming ground squirrel.

Effects of infection with mixed species of Eimeria (E. callospermophili, E. morainensis, and E. beecheyi) on the digestive physiology of Wyoming ground squirrels (Spermophilus elegans) are described. Infected and uninfected squirrels were administered arginine and methionine in saturated glucose solution. Blood was drawn at time 0 and 30 min postadministration. Significant differences were not found between infected and uninfected squirrels in plasma glucose, arginine, or methionine assimilation. In a second experiment, infected and uninfected squirrels were fed a food slurry of known caloric value. All feces were collected for 24 hr postfeeding. Differences were not detected in fecal caloric content or digestive efficiency. These results in conjunction with results reported in the literature suggest a reassessment of the "parasitic" nature of these squirrel symbionts. We propose that associations of some Eimeria species and hosts that evolve under natural conditions are examples of parasite-host interactions that often evolve toward commensalism.

Coccidian assemblages in the Wyoming ground squirrel, Spermophilus elegans elegans.

One thousand nineteen Wyoming ground squirrels (Spermophilus elegans elegans) from 4 populations in southern Wyoming were examined for intestinal parasites. The most prevalent parasites were 6 species of coccidia: Eimeria beecheyi, Eimeria bilamellata, Eimeria callospermophili, Eimeria larimerensis, Eimeria morainensis, and Eimeria spermophili. Most ground squirrels harbored 2 or more species. This eimerian assemblage was present across populations and over years. Differences in the prevalence of infection were not found among host age classes or between sexes. The presence or absence of helminths was independent of the presence and absence of Eimeria. A log-linear model to test the independence of the distribution of Eimeria spp. among hosts revealed 3 significant positive associations, for E. bilamellata and E. beecheyi, E. morainesis and E. callospermophili, and E. larimerensis and E. bilamellata.