Development and rudimentation of the peripheral olfactory system in the harbor porpoise Phocoena phocoena (Mammalia: Cetacea)

Abstract Serial sections of 13 embryos and fetuses of the harbor porpoise from 10 mm crown‐rump length up to 167 mm total length were studied. Unlike the adult animals, ontogenetic stages of 18–27 mm crown‐rump length still show a typical mammalian olfactory bulb. The olfactory bulb primordium is pe...

Full description

Bibliographic Details
Published in:Journal of Morphology
Main Authors: Oelschläger, Helmut A., Buhl, Eberhard H.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1985
Subjects:
Online Access:http://dx.doi.org/10.1002/jmor.1051840309
http://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjmor.1051840309
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjmor.1051840309
https://onlinelibrary.wiley.com/doi/pdf/10.1002/jmor.1051840309
Description
Summary:Abstract Serial sections of 13 embryos and fetuses of the harbor porpoise from 10 mm crown‐rump length up to 167 mm total length were studied. Unlike the adult animals, ontogenetic stages of 18–27 mm crown‐rump length still show a typical mammalian olfactory bulb. The olfactory bulb primordium is penetrated by olfactory nerve fibers, the latter passing through the cribriform plate. However, the olfactory bulb anlage is gradually reduced in later stages, its placodal component being largely uncoupled from the telencephalon. As a ganglionlike structure, the remains of the placodal component stay in contact with the nasal septum and mucosa via thin bundles of nerve fibers. The ganglion and plexus can be traced within the meninges until the adult stage of the porpoise. There is strong evidence that they represent the material of the terminalis system, which cannot be distinguished from the olfactory system in earlier stages. A vomeronasal organ could not be detected in the embryonal and fetal material investigated.