Date of Graduation

Spring 2017


Master of Science in Biology



Committee Chair

Alicia Mathis


reproductive behavior, oviposition, kinematic analysis, paternal care, Cryptobranchus alleganiensis bishopi

Subject Categories



The Ozark hellbender (Cryptobranchus alleganiensis bishopi) is a federally endangered aquatic salamander. While some anecdotal observations have been reported, no quantitative assessments of reproductive behaviors have been made. I quantified video-recordings of two breeding events at the Saint Louis Zoo. Hellbenders were housed in an indoor stream outfitted with 4 cameras. General activity and agonistic behaviors increased through the first oviposition, peaked during inter-oviposition, and declined abruptly following the second oviposition. Following oviposition, males guard their eggs until hatching. I also quantified behavior of a guarding male from video footage collected by MDC from a nest in the North Fork of the White River. I observed tail-fanning of eggs, rocking, foraging at the nest, nest occupancy, egg cannibalism, and behavior of fishes/crayfish at the nest. There were high frequencies of tail-fanning and rocking, behaviors which increase aeration. The male rarely left the nest unguarded and spent over half of the time at the nest exposed at the nest entrance. Potential egg predators observed included centrarchid, cyprinid, ictalurid, and percid fishes, with centrarchids being the most common and exhibiting the most interest in the nest. The frequency of foraging by the male was low (n = 8 strikes), with a 37% success rate; all successful strikes were to small cyprinids. Understanding spawning and nest-guarding behaviors can be used to inform management decisions and captive breeding programs.


© Rachel Ann Settle

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