Marine Science

Marine Science

Senior Theses 2003

Kathleen Tripp (2003). Functional morphology of the ovaries of the Florida manatee (Trichechus manatus latirostris)
Faculty advisor: Nanette Nascone-Yoder


The gross anatomy of the reproductive tract in the Florida manatee (Trichechus manatus latirostris) has not been adequately studied. This is particularly true of the ovaries and the pouch of peritoneum, the ovarian bursa, which surrounds them. The role of the hypogastric fossa in determining ovary position and shape in the manatee has also not been previously investigated.

This study examined the gross morphology of the manatee ovary and its structures. Examinations were completed at necropsy, as well as following fixation in 10% NBF. This examination included ovarian measurements, determination of ovarian zones, measurement and identification of all ovarian structures, and assignment of the female to a particular reproductive category, based upon the structures identified during examination. Uterine and mammary exams were also completed to help assign females to the proper reproductive category. Approximately 90 pairs of ovaries were examined, at least in part, for this study. Fetal ovaries, ovaries of immature females, and ovaries of females in varying stages of sexual maturity were examined in this study. Procedures are discussed for removing the ovaries, intact within their bursae, from the abdominal cavity.

The positioning of each ovary within its hypogastric fossa, along with the bursa's influence on the ovary, appear to be the two main structural factors influencing ovary shape. Considerable variation was observed among the ovaries of females in a single reproductive class, as well as between the two ovaries of a single female. These differences include size, shape, coloration, and level of structural development on the active ventral surface. The boundaries of the cortex and medulla were established and the manatee was determined not to possess a tunica albuginea. The medulla was found to (be highly invested with fat, in addition to standard connective tissue and vascular components. A sequence of structural development and degeneration was created, based upon the structures observed on ovaries examined. Schematics were also created for “typical” ovaries of each reproductive state. These will be used to identify structures at necropsy and help determine reproductive state.

Student Research