Serotonergic, sensory modifications in the apical ganglion during development to metamorphic competence in larvae of the dendronotid nudibranchs Melibe leonina and Tritonia diomedea
Article first published online: 2 SEP 2008
Copyright © 2008 Wiley-Liss, Inc.
Microscopy Research and Technique
Volume 71, Issue 12, pages 863–869, December 2008
How to Cite
Kempf, S. C. (2008), Serotonergic, sensory modifications in the apical ganglion during development to metamorphic competence in larvae of the dendronotid nudibranchs Melibe leonina and Tritonia diomedea. Microsc. Res. Tech., 71: 863–869. doi: 10.1002/jemt.20630
- Issue published online: 18 NOV 2008
- Article first published online: 2 SEP 2008
- Manuscript Accepted: 25 JUL 2008
- Manuscript Received: 13 JUN 2008
- Alabama Agricultural Experiment Station
- parampullary neuron;
- apical organ;
The following investigation examines changes in the distance between the right and left dendritic termini arising from the serotonergic sensory neurons found in the apical ganglion of the larval dendronotid nudibranchs, Melibe leonina and Tritonia diomedea. A significant increase in separation, that is different in extent, occurs in both species as they grow from hatching to metamorphic competence. Competent M. leonina larvae exhibit a separation that is about 4.5 times that at hatching, whereas competent larvae of T. diomedea show an increase that is only 1.6times that at hatching. The increase in separation of the lateral, serotonergic, dendritic termini (particularly in M. leonina) may allow the larva to more effectively assess left versus right differences in an as yet unknown sensory stimulus. The serotonergic innervation that arises from the apical ganglion is known to be associated with the muscles and large ciliated cells of the velum. Better right versus left discrimination of sensory stimuli experienced during the pelagic or settling larval phases may allow the larva to more precisely control swimming activities such that the likelihood of successful feeding or settlement behavior is increased. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc.