Development of the excretory system in the polyplacophoran mollusc, Lepidochitona corrugata: The protonephridium
Article first published online: 19 MAY 2011
Copyright © 2011 Wiley-Liss, Inc.
Journal of Morphology
Volume 272, Issue 8, pages 972–986, August 2011
How to Cite
Baeumler, N., Haszprunar, G. and Ruthensteiner, B. (2011), Development of the excretory system in the polyplacophoran mollusc, Lepidochitona corrugata: The protonephridium. J. Morphol., 272: 972–986. doi: 10.1002/jmor.10964
- Issue published online: 5 JUL 2011
- Article first published online: 19 MAY 2011
- Manuscript Accepted: 2 MAR 2011
- Manuscript Revised: 25 FEB 2011
- Manuscript Received: 11 JUN 2010
- DFG (German Science Foundation). Grant Number: RU-895/4-1
- transmission electron microscopy;
- interactive three-dimensional visualization;
A single pair of protonephridia is the typical larval excretory organ of molluscs. Their presence in postlarval developmental stages was discovered only recently. We found that the protonephridia of the polyplacophoran mollusc, Lepidochitona corrugata, achieve their most elaborate differentiation and become largest during the postlarval period. This study describes the protonephridia of L. corrugata using light and electron microscopy and interactive three-dimensional visualization. We focus on the postlarval developmental period, in which the protonephridia consist of three parts: the terminal part with the ultrafiltration sites at the distal end, the voluminous protonephridial kidney, and the efferent nephroduct leading to the nephropore. The ultrafiltration sites show filtration slits between regularly arranged thin pedicles. The ciliary flame originates from both the terminal cell and the duct cells of the terminal portion. The efferent duct also shows ciliation. The most conspicuous structures, the protonephridial kidneys, are voluminous swellings composed of reabsorptive cells (“nephrocytes”). These cells exhibit strong vacuolization and an infolding system increasing the basal surface. The protonephridial kidneys, previously not reported at such a level of organization in molluscs, strikingly resemble (metanephridial) kidneys of adult molluscan excretory systems. J. Morphol., 2011. © 2011 Wiley-Liss, Inc.