Stanley E. Trauth

PHYSIOLOGICAL TRADE-OFFS BETWEEN IMMUNITY AND REPRODUCTION IN THE NORTHERN CRICKET FROG (ACRIS CREPITANS)

Investigations of natural history trade-offs between reproduction and immunity are common throughout the literature. Most previous studies of such trade-offs have focused on how resources can be drawn from immune response to fuel reproduction. Our results demonstrate that resources also can be shifted from reproduction to immunity. Immunologically-challenged male northern cricket frogs (Acris crepitans) expressed reduced investment in reproduction. Spermatic cyst diameter, germinal epithelium depth, and gonadosomatic index were smaller in antigen-injected males relative to those injected with a sham (saline injected) and noninjected control animals. Although body size increased in all groups during this study, linear growth and body mass did not appear to be significantly different among these three treatment groups. These results demonstrate indirectly that in A. crepitans immune response may increase metabolic demand for resources and fuel that need from the stores normally used to support male reproduction. We speculate that anything eliciting an immune response in this species may reduce male fertility, so pathogens and toxins at levels that are currently believed to be relatively harmless may impact populations in ways we could not previously predict.

A FORTY-THREE YEAR MUSEUM STUDY OF NORTHERN CRICKET FROG (ACRIS CREPITANS) ABNORMALITIES IN ARKANSAS: UPWARD TRENDS AND DISTRIBUTIONS

The northern cricket frog (Acris crepitans) is a resident of streams, rivers, and wet-lands of eastern North America. We documented abnormalities in A. crepitans housed in the Arkansas State University Museum of Zoology Herpetology Collection. Abnormality frequency increased from 1957 to 2000 (χ2=43.76, df=3, P<0.001). From 1957 through 1979 only 3.33% of specimens were unusual. This rate was 6.87% during the 1990s, and in 2000 it was 8.48%. High frequencies of abnormalities were identified in the following Ozark highland counties: Sharp, Lawrence, and Randolph. We observed 104 abnormalities among 1,464 frogs (7.10%). The differential abnormality frequencies observed between the Arkansas lowlands and highlands are striking. The Ozarks had significantly higher frequencies of abnormalities than other Arkansas regions (χ2=59.76, df=4, P<0.001). The Ouachita Mountains had significantly higher frequencies than the Gulf Coastal Plain, Delta, or Arkansas River Valley (χ2=13.172, df=3, P<0.01). There was no difference in abnormality frequency between the Gulf Coastal Plain, Delta, and Arkansas River Valley (χ2=0.422, df=2, P>0.70). Proposed hypotheses for distributions include: 1) A. crepitans might possess naturally high abnormality levels, and land use practices of the Delta may reduce this variability; 2) an unknown xenobiotic may be in Ozark streams causing increased numbers of abnormalities; 3) the museums collection effort may be skewed; 4) Delta habitat might be more favorable for green tree frogs (Hyla cinerea) allowing this species to drive out A. crepitans through competition; here, abnormal metamorphs are not detected because they are even less competitive than normal individuals.

New host records for Myxidium serotinum (Protozoa: Myxosporea) from North American amphibians

Three hundred twenty-five amphibians (80 salamanders, 245 frogs and toads) from Arkansas and Texas, representing 28 species within 9 families (Ambystomatidae, Plethodontidae, Salamandridae, Sirenidae, Bufonidae, Hylidae, Leptodacytlidae, Microhylidae, Ranidae) were examined for gall bladder myxosporeans. Of these, 32 (10%) were found to harbor Myxidium serotinum Kudo and Sprague, 1940, including 3 (4%) of the salamanders and 29 (12%) of the frogs and toads. This report documents 6 new host records for M. serotinum in Ambystoma opacum, Bufo americanus charlesmithi, Bufo speciosus, Acris crepitans blanchardi, Gastrophryne olivacea, and Pseudacris streckeri illinoensis. In addition, the Great Plains narrowmouth toad G. olivacea represents the first microhylid host of Myxidium spp. worldwide.

Seasonal Changes in Reproductive Condition and Energy Stores in Cnemidophorus sexlineatus

Adult male and female Cnemidophorus sexlineatus enter hibernation in the fall with gonads in a regressed state. Cnemidophorus sexlineatus are still hibernating in March when sper- matogenesis and follicular development begin. Males emerge from hibernation in late April with testes containing spermatids or mature sperm. In female racerunners follicular development and vitellogenesis begin prior to their emergence in early May. The liver and fat bodies of both sexes attain maximum size at the onset of hibernation and are smallest during the summer activity months. Although some energy stores from the liver and fat bodies are used for winter maintenance, the bulk of this energy is utilized as reproductive activity begins in April and May.

New Host and Geographic Distribution Records for Some Endoparasites (Myxosporea, Trematoda, Cestoidea, Nematoda) of Amphibians and Reptiles from Arkansas and Texas, U.S.A.

Abstract A variety of amphibian (2 salamanders, 4 frogs, and 2 toads) and reptilian (3 turtles, 2 lizards, and 5 snakes) species and subspecies from 11 counties of Arkansas and 6 counties of Texas were collected during several months between 1968 and 2004 and examined for endoparasites. Twenty previously described parasite species were found, including 2 myxozoans, 7 trematodes, 1 cestode, and 10 nematodes. We document 18 new host and 18 new geographic distribution records for these select parasites.

The importance of comparative phylogeography in diagnosing introduced species: a lesson from the seal salamander, Desmognathus monticola

BackgroundIn most regions of the world human influences on the distribution of flora and fauna predate complete biotic surveys. In some cases this challenges our ability to discriminate native from introduced species. This distinction is particularly critical for isolated populations, because relicts of native species may need to be conserved, whereas introduced species may require immediate eradication. Recently an isolated population of seal salamanders, Desmognathus monticola, was discovered on the Ozark Plateau, ~700 km west of its broad continuous distribution in the Appalachian Mountains of eastern North America. Using Nested Clade Analysis (NCA) we test whether the Ozark isolate results from population fragmentation (a natural relict) or long distance dispersal (a human-mediated introduction).ResultsDespite its broad distribution in the Appalachian Mountains, the primary haplotype diversity of D. monticola is restricted to less than 2.5% of the distribution in the extreme southern Appalachians, where genetic diversity is high for other co-distributed species. By intensively sampling this genetically diverse region we located haplotypes identical to the Ozark isolate. Nested Clade Analysis supports the hypothesis that the Ozark population was introduced, but it was necessary to include haplotypes that are less than or equal to 0.733% divergent from the Ozark population in order to arrive at this conclusion. These critical haplotypes only occur in < 1.2% of the native distribution and NCA excluding them suggest that the Ozark population is a natural relict.ConclusionOur analyses suggest that the isolated population of D. monticola from the Ozarks is not native to the region and may need to be extirpated rather than conserved, particularly because of its potential negative impacts on endemic Ozark stream salamander communities. Diagnosing a species as introduced may require locating nearly identical haplotypes in the known native distribution, which may be a major undertaking. Our study demonstrates the importance of considering comparative phylogeographic information for locating critical haplotypes when distinguishing native from introduced species.

Placobdella cryptobranchii (Rhynchobdellida: Glossiphoniidae) on Cryptobranchus alleganiensis bishopi (Ozark Hellbender) in Arkansas and Missouri

Abstract Placobdella cryptobranchii is a rarely collected leech of the Ozark hellbender (Cryptobranchus alleganiensis bishopi) in northern Arkansas and southern Missouri, U.S.A. Between October 2002 and August 2005, 58 hellbenders were examined from Eleven Point River (Randolph Co., Arkansas and Oregon Co., Missouri), the north fork of the White River (Ozark Co., Missouri), and the Spring River (Fulton Co., Arkansas). Forty-one of the 58 hellbenders (70.7%) were infested with 1–140 leeches with a mean intensity (±SD) of 8.7 (±22.1) and a relative abundance (±SD) of 6.3 (±18.9). Contingency table analysis and t-tests revealed no significant differences in prevalence and mean intensity among various years and localities sampled. Leech size did not substantially change over the time period sampled. The dorsal pigmentation of live specimens of P. cryptobranchii is described for the first time.

Helminth Parasites of the Grotto Salamander, Eurycea spelaea (Caudata: Plethodontidae), from Northern Arkansas and Southern Missouri, U.S.A

Abstract Thirty-eight larval and adult Eurycea (=Typhlotriton) spelaea were borrowed from the Arkansas State University Museum Herpetological (ASUMZ) collection and examined for helminth parasites. These salamanders were collected at various times between 1936–1988 from locales in Independence, Izard, Sharp, and Stone counties, Arkansas, U.S.A., and Boone, Howell, and Taney counties, Missouri, U.S.A. In addition, 2 larval E. spelaea were collected more recently (March 2001 and May 2004) from Fulton and Madison counties, Arkansas, and 8 more larvae were collected (March 2003) from 2 caves in Shannon County, Missouri. Eight of the ASUMZ salamanders and 1 larvae from Madison County, Arkansas (9/40, 22.5%) harbored infections, including 1 (2.5%) with the trematode Plagioporus gyrinophili Catalano and Etges, 1981; 3 (7.5%) with the cestode Bothriocephalus typhlotritonis Reeves, 1949; 5 (12.5%) with the trichurid nematode Amphibiocapillaria tritonispunctati (Diesing, 1851) Moravec, 1982; 1 (2.5%) with the seuratoid nematode Omeia papillocauda Rankin, 1937, and 1 (2.5%) with the acanthocephalan Fessisentis vancleavei (Hughes and Moore, 1943) Nickol, 1972. In addition, all 8 larval E. spelaea from Shannon County, Missouri, harbored neascus type metacercariae of an undetermined strigeoid trematode in their gills and body tissues. Plagioporus gyrinophili, O. papillocauda, and F. vancleavei represent new helminth records for this host; new geographic distributional records are documented for P. gyrinophili and B. typhlotritonis.

A New Species of Chloromyxum (Myxozoa: Chloromyxidae) from the Gall Bladder of Eurycea spp. (Caudata: Plethodontidae) in North America

A previously undescribed species of Chloromyxum (Myxozoa: Chloromyxidae) was found in plasmodia adhering to the epithelium of the gall bladders in salamanders of the genus Eurycea (Caudata: Plethodontidae) from Arkansas and Texas (USA) in November, December, and January, 1987 to 1994. Bivalved spores of Chloromyxum salamandrae sp. n. from Eurycea multiplicata griseogaster (type host) were subspherical, with a mean size ± SD of 8.3 ± 0.3 × 7.7 ± 0.4 (7.8 to 8.8 × 7.0 to 8.2) μm (n = 20), and had a shape index (length/width) of 1.07 ± 0.03 (1.02 to 1.14). The valves measured 0.8 to 1.0 μm thick and had 10 to 12 external striations each. Each of the four polar capsules were piriform, with a mean size ± SD of 4.0 ± 0.1 × 2.6 ± 0.1 (3.8 to 4.2 × 2.4 to 2.8) μm (n = 20), and there appeared to be about four coils of each polar filament. The sporoplasm was irregular in shape and appeared to be binucleate. Adherent plasmodia observed in winter months were small, with a mean size ± SD of 31.5 ± 6.3 × 24.9 ± 2.6 (20 to 40 × 20 to 30) μm (n = 20), and contained zero to eight disporoblastic spores each. The myxozoan occurred in nine of 14 E. multiplicata griseogaster, three of eight E. multiplicata multiplicata, and two of 12 E. neotenes. This represents the first report of a Chloromyxum sp. from Amphibia in the Western hemisphere.

COCCIDIAN PARASITES (APICOMPLEXA) FROM SNAKES IN THE SOUTHCENTRAL AND SOUTHWESTERN UNITED STATES: NEW HOST AND GEOGRAPHIC RECORDS

Four hundred thirty-five leptotyphlopid, colubrid, elapid, and viperid snakes were collected from various localities in Arkansas, New Mexico, Oklahoma, and Texas, and their feces were examined for coccidian parasites. Of these, 131 (30%) were passing oocysts or sporocysts of at least 1 coccidian; 88 (67%) of the infected snakes had only 1 species of coccidian when they were examined. Aquatic and semiaquatic snakes accounted for 48% of the infections, whereas strictly terrestrial snakes comprised the other 52%. There was more than a 2-fold difference in prevalence among these 2 groups as 63 of 129 (49%) of the aquatic and semiaquatic snakes versus 68 of 306 (22%) of the terrestrial snakes harbored coccidia. Most terrestrial snakes were infected by species of Caryospora and Sarcocystis that are either facultatively or obligatorily heteroxenous. The aquatic and semiaquatic species most often harbored eimerians. Attempts to transmit some of the Sarcocystis spp. experimentally from Crotalus atrox to Mus musculus, Peromyscus leucopus, Peromyscus maniculatus, or Microtus ochrogaster were unsuccessful. This report documents 27 new host and several distributional records for coccidians from snakes in the southcentral and southwestern United States.