Scanning electron microscopy of the oviduct of Salamandra salamandra (L.) (Amphibia, Urodela)

The oviduct of non-pregnant females of the ovoviviparous salamander, Salamandra salamandra, was examined using SEM-techniques. In the luminal epithelium polygonal ciliated cells were found along the entire surface of the oviduct, except the uterus, and non-ciliated cells with a varying number of short or long microvilli. The ciliated cells occur in the most anterior portion of the oviduct, the pars recta; they are sparsely distributed in the p. convoluta I, but abundant in the p. convoluta II and III. Non-ciliated cells comprise several small gland cells, restricted to the p. convoluta I, II, III, and undifferentiated cells both provided with microvilli, but difficult to be discerned from their surface appearance. The p. convoluta I, II, III is characterized by three types of secretory cells forming tubular glands, each type confined to a given zone. The secretory cells have slender microvilli at their surfaces. In freeze-cracked glands details of their secretory products can be visualized. The findings are compared to previously published TEM-investigations and discussed with regard to some functions of the oviduct during reproduction.