Degree Name

MS (Master of Science)



Date of Award


Committee Chair or Co-Chairs

J. Leonard Robertson

Committee Members

Thomas F. Laughlin, W. David Currie


Sex reversal in fish can occur as a result of disturbances in natural conditions or laboratory manipulations. Trenbolone Acetate (TBA), a synthetic anabolic-androgenic steroid used mainly in the cattle industry, was applied to female Betta splendens, a sexually dimorphic fish. Previously, females were analyzed for secondary sex characteristics after treatment with TBA, increased temperature, or a combination of both. This study focused on primary sex characteristics by histological examination. Gonads were surgically removed and prepared following basic histological techniques. Following H&E staining, sections were observed for signs of ovarian regression, as well as signs of testicular formation. The presence of TBA significantly reduced the size of the gonad and the number and size of vitellogenic oocytes, indicating a loss of ovarian function. Temperature had a synergistic effect on TBA, as more oocytes were atretic and interstitial tissue was more abundant, some with clear spermatocysts. Temperature alone had no significant effect.

Document Type

Thesis - Open Access


Copyright by the authors.