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Fisheries managers are restoring native populations by removing nonnative fishes worldwide. Increasingly, the piscicide rotenone is used to accomplish this. Fish introductions and removals change the aquatic environment, and it is important to consider the impacts of these actions on nontarget species, including amphibians. Laboratory experiments have shown that rotenone can negatively affect tadpoles. We therefore assessed the effects of rotenone used on two wild amphibian populations. The commercial piscicide formulation CFT Legumine (5% rotenone) was applied at 1 mg/L (50 µg/L rotenone) to a lake containing nonnative trout in Yellowstone National Park (YNP) in 2006 and two fishless wetlands on private lands in southwestern Montana in 2008. Amphibian surveys were conducted immediately prior to and after the rotenone treatments to obtain tadpole population estimates. Follow-up surveys were conducted 1 year posttreatment to estimate tadpole recovery. In YNP, additional surveys were conducted 2 and 3 years postapplication to observe longer-term effects of fish removal and the subsequent introduction of native fish. Within 24 h following application of rotenone, there was 100% mortality in gill-breathing tadpoles, but nongill-breathing metamorphs, juveniles, and adults were apparently unaffected. In the years following, tadpoles repopulated all waters and population levels were similar to, or, in the case of YNP because of concurrent fish removal, higher than pretreatment levels. In YNP, tadpole abundance and distribution decreased after westslope cutthroat trout Oncorhynchus clarkii lewisiwere stocked in the treated lake. Received October 22, 2011; accepted May 4, 2012

The piscicide rotenone is commonly used to remove nonnative fishes from natural aquatic systems. While the effects of rotenone on fish are well documented, the effects of this chemical on amphibians are less well known. We determined the toxicity of the rotenone formulation CFT Legumine (5% rotenone) to three ages—Gosner age ranges 21–25, 30–35, and 40–45—of tadpoles of the Columbia spotted frog Rana luteiventrisand the boreal toad Anaxyrus boreasunder laboratory conditions. Tadpoles of both species were exposed to 0.1, 0.5, and 1.0 mg/L CFT Legumine (0.005, 0.025, and 0.050 mg/L rotenone, respectively) in static, 96-h exposure trials; surviving individuals were placed in rotenone-free water and raised until metamorphosis. In an additional experiment, Columbia spotted frog tadpoles were exposed to 1.0 mg/L CFT Legumine for 1, 2, 3, or 4 h before being placed in rotenone-free water for the duration of a 96-h exposure period. Tadpole mortality increased with increases in CFT Legumine concentration and exposure period. Individuals exposed to 1.0 mg/L of product experienced significantly greater mortality than did control tadpoles (P< 0.001), with 99–100% mortality occurring in the youngest age-group (Gosner 21–25) in both species. In Columbia spotted frog tadpoles, mortality decreased as age increased, while age did not affect mortality in boreal toad tadpoles. Rotenone produced no biologically significant effects on growth or metamorphosis. Our findings suggest that the use of 1.0 mg/L CFT Legumine to remove nonnative fish may cause significant mortality to larval amphibians if they are exposed for 96 h; exposures to lower dosages (0.5 mg/L of product) or for shorter durations (=4 h), however, resulted in less mortality. Fisheries managers can use these results to improve amphibian conservation in fish restoration areas and reduce the impacts on larval amphibian populations.

Abstract:Wildlife managers increasingly are using remotely sensed imagery to improve habitat delineations and sampling strategies. Advances in remote sensing technology, such as hyperspectral imagery, provide more information than previously was available with multispectral sensors. We evaluated accuracy of high-resolution hyperspectral image classifications to identify wetlands and wetland habitat features important for Columbia spotted frogs (Rana luteiventris) and compared the results to multispectral image classification and United States Geological Survey topographic maps. The study area spanned 3 lake basins in the Salmon River Mountains, Idaho, USA. Hyperspectral data were collected with an airborne sensor on 30 June 2002 and on 8 July 2006. A 12-year comprehensive ground survey of the study area for Columbia spotted frog reproduction served as validation for image classifications. Hyperspectral image classification accuracy of wetlands was high, with a producer's accuracy of 96% (44 wetlands) correctly classified with the 2002 data and 89% (41 wetlands) correctly classified with the 2006 data. We applied habitat-based rules to delineate breeding habitat from other wetlands, and successfully predicted 74% (14 wetlands) of known breeding wetlands for the Columbia spotted frog. Emergent sedge microhabitat classification showed promise for directly predicting Columbia spotted frog egg mass locations within a wetland by correctly identifying 72% (23 of 32) of known locations. Our study indicates hyperspectral imagery can be an effective tool for mapping spotted frog breeding habitat in the selected mountain basins. We conclude that this technique has potential for improving site selection for inventory and monitoring programs conducted across similar wetland habitat and can be a useful tool for delineating wildlife habitats.

We assessed the diversity and phylogeny of Saprolegniaceae on amphibian eggs from the Pacific Northwest, with particular focus on Saprolegnia ferax, a species implicated in high egg mortality. We identified isolates from eggs of six amphibians with the internal transcribed spacer (ITS) and 5.8S gene regions and BLAST of the GenBank database. We identified 68 sequences as Saprolegniaceae and 43 sequences as true fungi from at least nine genera. Our phylogenetic analysis of the Saprolegniaceae included isolates within the genera Saprolegnia, Achlyaand Leptolegnia. Our phylogeny grouped S. semihypogynawith Achlyarather than with the Saprolegniareference sequences. We found only one isolate that grouped closely with S. ferax, and this came from a hatchery-raised salmon (Idaho) that we sampled opportunistically. We had representatives of 7–12 species and three genera of Saprolegniaceae on our amphibian eggs. Further work on the ecological roles of different species of Saprolegniaceae is needed to clarify their potential importance in amphibian egg mortality and potential links to population declines.

Abstract: Introduced trout have often been implicated in the decline of high-mountain amphibian populations, but few studies have attempted to understand whether fish stocking also influences the distribution and abundance of amphibians throughout entire mountain basins, including the remaining fishless lakes. We examined this relationship using the relative abundance of long-toed salamanders (Ambystoma macrodactylum) and Columbia spotted frogs (Rana luteiventris) in fish-containing and fishless lentic sites in basins with varying levels of historic fish stocking. All lentic waters were surveyed for fish and amphibians in 11 high-elevation basins in the Frank Church-River of No Return Wilderness, Idaho, between 1994 and 1999. We found introduced trout (Oncorhynchus clarki, O. mykiss, O. m. aguabonita) in 43 of the 101 sites, representing 90% of the total surface area of lentic water bodies available. At the scale of individual water bodies, after accounting for differences in habitat characteristics between fish-containing and fishless sites, the abundance of amphibians at all life stages was significantly lower in lakes with fish. At the basin scale, densities of overwintering life stages of amphibians were lower in the fishless sites of basins where more habitat was occupied by trout. Our results suggest that many of the remaining fishless habitats are too shallow to provide suitable breeding or overwintering sites for these amphibians and that current trout distributions may eventually result in the extirpation of amphibian populations from entire landscapes, including sites that remain in a fishless condition.

Coadaptation predicts a match between the thermal physiology and thermoregulatory behavior of reptiles. We tested this prediction by studying the digestive biology of rubber boas (Charina bottae). We measured the thermal dependence of gastric digestive rate and passage rate in rubber boas from 10°C to 35°C. We examined the effect of digestion on their thermal preference by measuring the temperatures of C. bottae in a thermal gradient before and after feeding. While the passage rates calculated from the body temperatures of digesting snakes were higher than the passage rates calculated from the body temperatures of nondigesting snakes, there was no difference in calculated digestive rates. These results indicate that the thermoregulatory behavior of C. bottae may be more tightly correlated with factors affecting passage rate than with digestive rate alone. Results of simulating the constraints of the thermal environment on the digestive biology of C. bottae showed that digestion would take more than twice as long in the spring as in the summer. In addition, during the summer, snakes thermoregulating as digesting snakes would pass food 12% faster than those thermoregulating as nondigesting snakes. These results demonstrate how interpretation of laboratory studies can be improved when combined with measurements of appropriate environmental conditions.

The body temperature (Tb) of garter snakes (Thamnophis elegans) can vary considerably in the course of a day (e.g., 4-33 C), and information on how Tbaffects physiological and behavioral processes is required to evaluate the significance of that variation. We measured crawling speed, swimming speed, tongue-flicking rate, digestive rate, and oxygen consumption at Tb's of 5-35 C in snakes collected in eastern Washington and acclimated to September field photoperiod and temperature cycles. All functions were strongly dependent on Tb. The maximum speed of crawling (X̄= 0.74 m s−1) occurred at Tb= 34.5 C; that of swimming (X̄= 0.69 m s−1) occurred at Tb= 28.5. At < 30 C, the snakes crawled more slowly than they swam, but the reverse was true at higher Tb. At Tb= 30 C, the snakes moved their tongues up and down at a maximum rate of 22 Hz. Digestion rate increased sharply above 20 C, to a maximum of 0.45 mice/day within the Tbrange of 25-35 C. All snakes regurgitated their meal at 10 C. The Q10values for mass-specific oxygen consumption over the 5-15, 15-25, and 25-35 C Tbranges were 2.4, 1.3, and 5.0, respectively. Among the performances studied, swimming speed was the least sensitive, and digestion rate the most sensitive, to Tb. FieldTbdata indicate that all functions would be near maximum levels during the day but would be significantly reduced at night. We conclude that no single Tbis best for the ecological tasks of prey capture, predator avoidance, and energy conservation.

Neurodiagnostic studies allow the physician to determine the location of the lesion producing facial paralysis and the physiological extent of nerve involvement. The Schirmer test for lacrimation, the stapedial-reflex test, electrogustometry, and submaxillary salivary gland secretion studies have been found to be most helpful in determining the site of the lesion.The physiological extent of nerve involvement is determined by the nerve excitability test and electromyography. Therapy for patients with facial nerve paralysis must be based upon the cause of the paralysis, whether or not facial weakness is complete, the site of the lesion, and the physiological extent of nerve involvement.

ALTHOUGH endogenous lactic acid has been recognized as a source of metabolic acidosis for many years in a variety of situations,1-5 it was not until the publication by Huckabee of his clinical observations of the significance of lactic acid acidosis 6,7 that great interest was stimulated in this condition. The demonstration that severe metabolic acidosis, frequently of fatal outcome, was a significant clinical problem has led to the increasing recognition of this situation in clinical practice.5,8-17The definition of lactic acidosis remains arbitrary. Since the production of lactate is always accompanied by an equivalent appearance of hydrogen ion, significant elevation in blood lactate must be interpreted as lactic acidosis regardless of resultant arterial pH or bicarbonate levels. Qualifying factors include the degree of compensation for the metabolic acidosis, represented by arterial pH, eventual outcome (survival or fatality), the presence or absence of clinical symptoms of metabolic acidosis,