Brandon C. Moore and Ketan Mathavan contributed equally to this manuscript.
Morphology and Histochemistry of Juvenile Male American Alligator (Alligator mississippiensis) Phallus
Article first published online: 21 DEC 2011
Copyright © 2011 Wiley Periodicals, Inc.
The Anatomical Record
Volume 295, Issue 2, pages 328–337, February 2012
How to Cite
Moore, B. C., Mathavan, K. and Guillette, L. J. (2012), Morphology and Histochemistry of Juvenile Male American Alligator (Alligator mississippiensis) Phallus. Anat Rec, 295: 328–337. doi: 10.1002/ar.21521
- Issue published online: 11 JAN 2012
- Article first published online: 21 DEC 2011
- Manuscript Accepted: 28 AUG 2011
- Manuscript Revised: 20 JUL 2011
- Manuscript Received: 20 APR 2011
- NIH. Grant Numbers: R21 HD047885-01, R21 ES014053-01
- Howard Hughes Medical Institute Professors program
- Florida Fish and Wildlife Conservation Commission
- erectile tissues
Phalli of male crocodilians transfer sperm to female cloaca during sexual intercourse, resulting in internal fertilization. For over a century there have been scientific descriptions of crocodilian phallus morphologies; however, little work has presented detailed cellular-level analyses of these structures. Here we present a histological investigation of the complex functional anatomy of the juvenile male American alligator phallus, including fibrous and vascular erectile structures, a variety of secretory epithelium morphologies, and observed immune cells. Using 3D reconstruction software, we show the shape and location of vascular erectile tissues within the phallus. Histochemical staining detected mucin-rich secretory cells in glandular epithelial cells of the phallic shaft and also of the semen-conducting ventral sulcus. Lymphoid aggregates, lymphocytes, and epithelial mucin coats suggest an active immune system in the phallus defending from both the external and intracloacal environments. These results better characterize the complexity of the alligator phallus and predict later reproductive functions during adulthood. Anat Rec, 2012. © 2011 Wiley Periodicals, Inc.