SREL Reprint #2055

Reproduction of the salamander, Siren intermedia Le Conte with especial reference to oviductal anatomy and mode of fertilization

David M. Sever1, Lisa C. Rania1,2, and John D. Krenz2,3

1Department of Biology, Saint Mary's College, Notre Dame, Indiana 46556
2Savannah River Ecology Laboratory, Aiken, South Carolina 29802
3Institute of Ecology, University of Georgia, Athens, Georgia 30602

Abstract: Reproduction was studied in a South Carolina population of the paedomorphic salamander Siren intermedia with emphasis on anatomy of the female oviduct. The oviduct forms 67-79% of the snout-vent length in this elongate species and can be divided into three portions. The atrium, 7-13% of oviducal length, is the narrow anteriormost portion, with the ostial opening immediately caudad of the transverse septum. The ampulla, 63-75% of oviducal length, is the highly convoluted, middle portion in which gelatinous coverings are added to the eggs during their passage. Hypertrophy of the oviducal glands in the ampulla causes the ampulla to increase in diameter during the ovipository season. The secretion of the eosinophilic oviducal glands is intensely positive following staining with the periodic acid-Schiff procedure and does not react with alcian blue at pH 2.5. This staining reaction, coupled with the presence of abundant rough endoplasmic reticulum and Golgi complexes, indicates that the secretion contains a glycoprotein. The ovisac, 16-25% of oviducal length, is the most posterior portion of the oviduct and holds up to 10-11 eggs prior to oviposition. Oviducal glands similar to those in the ampulla are absent in the ovisac. Oviposition in female sirens occurs during February-April in this population, and male spermiation is concurrent. Entire oviducts were sectioned from three females collected during the ovipository season and from two collected prior to the breeding season, and sperm were not found in the oviducts of these specimens. Thus no evidence was found for internal fertilization or sperm storage in the oviducts of sirens.

SREL Reprint #2055

Sever, D.M., L.C. Rania, and J.D. Krenz. 1996. Reproduction of the salamander, Siren intermedia Le Conte with especial reference to oviductal anatomy and mode of fertilization. Journal of Morphology 227:335-348.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).