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Showing 1 to 19 of 19 for “"Cryptobranchus"”.
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Seasonal Reproductive Changes in Cryptobranchus Alleganiensis
… testes, ovaries, and oviducts were studied in Cryptobranchus alleganiensis collected from the Niangua River, Missouri, from October 1979 through October 1980. Spermatogenesis occurred from late June through early August. Length, absolute weight, and relative weight of the testes were maximal by …
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A Re-Evaluation of the Pleistocene Hellbender, <em>Cryptobranchus guildayi</em>, and an Overview of <em>Cryptobranchus</em> Remains from Appalachian Caves.
<p><em>Cryptobranchus guildayi</em> is described as an extinct species of large salamander that is closely related to the hellbender, <em>Cryptobranchus alleganiensis</em>. The validity of this extinct taxon has been questioned, so an expanded osteological sample of modern hellbenders was used for …
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Reproductive Endocrinology of the Ozark Hellbender, Cryptobranchus Alleganiensis Bishopi
… in the serum of adult Ozark hellbenders, Cryptobranchus alleganiensis bishopi, were investigated from June 1993 to December, 1993. These dates included the periods before, during and after the breeding season. Radioimmunoassays were performed to measure the concentrations of estradiol, …
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Food Habits, Starvation and Growth in the Hellbender, Cryptobranchus Alleganiensis
Cryptobranchus alleganiensis were captured from the Niangua River of Missouri throughout 1974 for a food habits study. Crayfish were the dominant food item, with fish secondary; together, they constituted over 90 percent of stomach content weights in all months. Both fish and crayfish showed …
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Habitat Analysis of the Ozark Hellbender, Cryptobranchus Alleganiensis Bishopi, in Missouri
The habitat of the Ozark hellbender, Cryptobranchus alleganiensis bishopi, was investigated in the Northfork of the White River, Ozark County, Missouri. Microhabitat variables of water depth, current velocity, substrate, and embeddedness were measured for 259 hellbenders. A principal component …
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Changes in LDH Activity in Cryptobranchus Due to Imposed Environmental Stress
… acid. Its activity in the aquatic salamander, Cryptobranchus alleganiensis alleganiensis was studied. Water oxygen saturation was decreased from 100 to 25 to 10% to produce a state of hypoxia, thereby forcing respiration along anaerobic pathways. The effect of increasing temperature (5-25°C) …
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Responses Of Cryptobranchus Alleganiensis Alleganiensis To Different Oxygen Concentrations, Temperatures And Photoperiod
Cryptobranchus alleganiensis, a large aquatic salamander, was studied to determine if its underwater movements are respiratory in function. These animals also exhibit a side-to-side swaying motion, and various authors have suggested that this rocking is to produce a flow of water over the skin in …
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Status of the Ozark Hellbender (Cryptobranchus Alleganiensis Bishopi): a Long-Term Assessment
… populations of the long-lived Ozark hellbender, Cryptobranchus alleganiensis bishopi, in three rivers in Missouri, and compared the 1998 data to data from previous studies from the 1970's and 1980's. Ozark hellbenders appear to have declined in numbers. This decline is characterized by an …
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Improving the Utility of Artificial Shelters for Monitoring Eastern Hellbender Salamanders (Cryptobranchus alleganiensis alleganiensis)
Artificial shelters show great promise as novel, non-invasive tools for studying hellbenders, but their use thus far has faced several challenges. During initial trials in multiple river networks, artificial shelters routinely became blocked by sediment and dislodged during high stream discharge …
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Status of the Eastern Hellbender (Cryptobranchus Alleganiensis Alleganiensis) in Missouri: a Comparison of Past and Present Populations
Eastern hellbenders, Cryptobranchus alleganiensis alleganiensis, were collected from the Big Piney, Gasconade, and Niangua Rivers. Total length and mass measurements were taken for comparison with historical data from the same rivers. There have been substantial declines in the numbers of …
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The Influence of Environmental Conditions and Co-Occurring Parasites on Blood Physiology in Eastern Hellbenders (<i>Cryptobranchus alleganiensis</i>)
… of male Eastern Hellbender salamanders (<i>Cryptobranchus alleganiensis</i>) which remain with their nest for up to ~8 months and have frequent encounters with parasitic leeches (<i>Placobdella appalachiensis</i>) that transmit hematophagous endoparasites (Trypanosoma sp.), often resulting …
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The Effects Of Dissolved Oxygen Content Of Water On Blood Ph, Pco4, Po4 And Rocking Activity For Cryptobranchus Alleganiensis
… pCO₂, pO₂ and rocking activity were measured for Cryptobranchus alleganiensis. Measurements were taken at 100%, 75%, 50%, 25%, 20%, 15%, 10% and 0% saturation levels while temperature was held constant at 12°C. Results indicate that reduction of dissolved O₂ content of water does not have a …
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Effects of Land Use on Hellbenders (Cryptobranchus alleganiensis) at Multiple Levels and Efficacy of Artificial Shelters as a Monitoring Tool
… help focus conservation planning. Hellbenders (Cryptobranchus alleganiensis) are a freshwater species of increasing conservation concern that are suspected to have declined due to loss of forest cover. However, quantitative evidence of land use effects on hellbenders is lacking. I used a …
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The Influence of Reduced Forest Cover and Dissolved Oxygen on the Viability of Eggs from Eastern Hellbenders (<i>Cryptobranchus alleganiensis</i>)
Riparian deforestation is a significant threat to freshwater riverine ecosystems and sensitive fauna that depend on clean water. Sensitive aquatic species are vulnerable to the destruction of riparian forest cover which diminishes protection from pollutants, sedimentation, and solar radiation, …
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Down Stream [Appalachia]
… mussels; and the Eastern Hellbender Salamander (Cryptobranchus alleganiensis alleganiensis). This paper examines the context and content of this installation, its progression and influences, and themes of ecology and the environment in the Southeast United States.
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Home Range and Nocturnal Activity of the Ozark Hellbender
… nocturnal activity of seven Ozark hellbenders, Cryptobranchus alleganiensis bishipi, in the North Fork of the White River, Ozark County, Missouri, during a 14 day period in August, 1979. The mean elliptical home range for combined sexes was 90.01 m² (82.92 m² for males, 99.43 m² for females). …
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Age and Growth of the Ozark Hellbender
… growth rates of Ozark hellbenders, Cryptobranchus alleganiensis bishopi, from the North Fork of the White River, Missouri, were calculated by regression from growth of marked and recaptured hellbenders. Growth rates declined steadily after transformation, going from about 74 mm …