Research Library

Premium Convergent evolution of the vestibular organ in the subterranean mole‐rats, Cryptomys and Spalax , as compared with the aboveground rat, Rattus
Lindenlaub Thies,
Burda Hynek,
Nevo Eviatar
Publication year1995
Publication title
journal of morphology
Resource typeJournals
PublisherWiley Subscription Services
Abstract The membranous labyrinth of the vestibular organ (examined in toto) in two unrelated species of subterranean rodents, Cryptomys sp. from Zambia and Spalax ehrenbergi from Israel, was in many parameters (streamline length, curvature radius, and cross‐sectional area of the lumen) relatively or even absolutely (especially the cross‐sectional area) larger than in the laboratory Norway rat. The mechanical sensitivity of the vestibular organ (estimated according to the mathematical model of Oman et al., [1987] Acta. Otolaryngol (Stockh.) 103 :1–13) was similar in both subterranean rodent species and significantly higher than that in the laboratory rat. The most pronounced differences in morphometry and the resulting mechanical sensitivity between the subterranean forms and the rat occurred in the lateral (i.e., phylogenetically and ontogenetically most recent and presumably most plastic) semicircular duct. The area of the sensory epithelia, and density and total numbers of vestibular receptors, were estimated on surface specimens for both maculae and for all three cristae for all three species. While the density of hair cells in comparable sensory epithelia was similar in all three species, the sensory area and thus, also, the total receptor counts were significantly larger in both subterranean forms. The peripheral vestibular organ in subterranean rodents is, in comparison to a generalized aboveground dwelling form, i.e., the rat, progressively specialized, and in any case cannot be denoted as degenerate. © 1995 Wiley‐Liss, Inc.
Subject(s)anatomy , biology , ecology , neuroscience , rodent , vestibular system , zoology
SCImago Journal Rank0.652

Seeing content that should not be on Zendy? Contact us.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here