Trinh, Ngan, Clean Water Institute, Lycoming College, 1 College Place, Williamsport, PA, 17701, tringan@lycoming.edu; Mathes, Samuel, , Biochemistry, Nutrition, and Health Promotion, Mississippi State University, 100 Old Hwy 12, Mississippi State, MS, 39762, scm621@msstate.edu; Shablin, Samantha, Biochemistry, Nutrition, and Health Promotion Mississippi State University 100 Old Hwy 12 Mississippi State MS, 39762, ss4856@msstate.edu; Simpson, Austin, , Biochemistry, Nutrition, and Health Promotion, Mississippi State University, 100 Old Hwy 12, Mississippi State, MS, 39762; Kaunert, Matt, , Clean Water Institute Lycoming College, 1 College Place, Williamsport, PA, 17701, kaunert@lycoming.edu.
The Eastern Hellbender (Cryptobranchus a. alleganiensis) is a large-bodied (≤74 cm TL), long-lived (~50 yrs) aquatic salamander endemic to streams in the eastern United States and serves as an important indicator of stream habitat quality. Populations have declined significantly over the past five decades due to land use change, increased sedimentation, and reduced reproductive success. Because sex is indistinguishable outside of the breeding season (late August – September), traditional methods such as hormone analysis and ultrasonography have limited field applicability. In this study, we evaluated the use of Near-Infrared Reflectance Spectroscopy (NIRS) combined with chemometric analyses to identify sex-specific biochemical signatures in hellbenders. We collected hellbenders (n = 25 males; n = 14 females) from artificial nest box arrays in western Pennsylvania, a region with relatively stable populations. Spectral data were collected during the pre-breeding season (July – August) and analyzed to detect sex-related differences, and sex was confirmed via ultrasound. NIRS detected distinct spectral patterns between males and females, indicating biochemical variation associated with sex. However, the accuracy of classification was likely reduced by the small number of female samples. These findings demonstrate that NIRS has the potential to noninvasively discriminate sex in hellbenders outside of the breeding season and may offer a valuable tool for conservation and management of this declining Appalachian indicator species.
hellbender , amphibian , NIRS , sex discrimination