We documented abnormalities of Ozark hellbender (Cryptobranchus alleganiensis bishopi) populations in the Eleven Point River (Randolph County, Arkansas) and the Spring River (Fulton County, Arkansas) as part of ongoing monitoring efforts in this species. We found abnormalities in 90% (9 of 10) and 40% (36 of 97) of hellbenders in the Spring River and Eleven Point River, respectively, during the 2003-2004 field seasons. Most abnormalities found in Eleven Point hellbenders were generally less invasive and seemed to be more intrinsic to the species' natural history (i.e., vicissitudes of living), whereas those found in Spring River hellbenders were gross morphological aberrations. We compared the type and rate of observed abnormalities with those found in museum vouchers collected from the Spring River between 1970 and 1975. Abnormalities were found in 12.5% of the museum specimens from our Spring River localities. This rate is much higher than previously reported for hellbenders. The increase in the abnormality rate appears to be concurrent with the documented population decline observed in the Spring River. Our study illustrates an increasing trend of hellbenders exhibiting unusual morphological problems (e.g., epidermal papillomas, extreme abrasions/lacerations, fungal infections, etc.) and also stresses the need for inclusion of abnormalities observed in field data. The causes of hellbender abnormalities remain speculative; however, plausible explanations may be related to intraspecific interactions, anthropogenic interactions with the microhabitat, viral infections, non-point/point source pollution, and the preponderance of older individuals. These findings emphasize the need for a proactive conservation effort within this species.

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