REPRODUCTION OF THE SALAMANDER SIREN INTERMEDIA LE CONTE WITH SPECIALREFERENCE TO OVIDUCAL ANATOMY AND MODE OF FERTILIZATION

Reproduction was studied in a South Carolina population of the paedomo rphic salamander Siren intermedia with emphasis on anatomy of the fema le 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 ampull a, 63-75% of oviducal length, is the highly convoluted, middle portion in which gelatinous coverings are added to the eggs during their pass age. Hypertrophy of the oviducal glands in the ampulla causes the ampu lla to increase in diameter during the ovipository season. The secreti on of the eosinophilic oviducal glands is intensely positive following staining with the periodic acid-Schiff procedure and does not react w ith alcian blue at pH 2.5. This staining reaction, coupled with the pr esence of abundant rough endoplasmic reticulum and Golgi complexes, in dicates 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 t o those in the ampulla are absent in the ovisac. Oviposition in female sirens occurs during February-April in this population, and male sper miation is concurrent, Entire oviducts were sectioned from three femal es collected during the ovipository season and from two collected prio r 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. (C) 1996 Wiley-Liss, Inc.