QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online August 31, 2004
Journal of Experimental Biology 207, 3447-3462 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01157

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bartels, H. Articles by Potter, I. C. Search for Related Content PubMed PubMed Citation Articles by Bartels, H. Articles by Potter, I. C.

Review Article

Cellular composition and ultrastructure of the gill epithelium of larval and adult lampreys : Implications for osmoregulation in fresh and seawater

Helmut Bartels^1,* and Ian C. Potter²

¹ Anatomische Anstalt, Ludwig-Maximilians-Universität München, Pettenkoferstr. 11, 80336 München, Germany
² School of Biological Sciences and Biotechnology, Murdoch University, Murdoch 6150, Western Australia

^* Author for correspondence (e-mail: bartels{at}anat.med.uni-muenchen.de)

Accepted 21 June 2004

Lampreys, one of the only two surviving groups of agnathan (jawless) vertebrates, contain several anadromous species that, during their life cycle, thus migrate from fresh to seawater and back to freshwater. Lampreys have independently evolved the same overall osmoregulatory mechanisms as the gnathostomatous (jawed) and distantly related teleost fishes. Lamprey gills thus likewise play a central role in taking up and secreting monovalent ions. However, the ultrastructural characteristics and distribution of their epithelial cell types [ammocoete mitochondria-rich (MR) cell, intercalated MR cell, chloride cell and pavement cell] differ in several respects from those of teleosts. The ultrastructural characteristics of these cells are distinctive and closely resemble those of certain ion-transporting epithelia in other vertebrates, for which the function has been determined. The data on each cell type, together with the stage in the life cycle at which it is found, i.e. whether in fresh or seawater, enable the following proposals to be made regarding the ways in which lampreys use their gill epithelial cells for osmoregulating in hypo- and hypertonic environments. In freshwater, the intercalated MR cell takes up Cl^– and secretes H⁺, thereby facilitating the uptake of Na⁺ through pavement cells. In seawater, the chloride cell uses a secondarily active transcellular transport of Cl^– to provide the driving force for the passive movement of Na⁺ through leaky paracellular pathways between these cells.

Key words: lamprey, Agnatha, osmoregulation, gill epithelium, mitochondria-rich cell, chloride cell, pavement cell

This article has been cited by other articles:

				P. Reis-Santos, S. D. McCormick, and J. M. Wilson Ionoregulatory changes during metamorphosis and salinity exposure of juvenile sea lamprey (Petromyzon marinus L.) J. Exp. Biol., March 15, 2008; 211(6): 978 - 988. [Abstract] [Full Text] [PDF]