Cytological basis of photoresponsive behavior in a sponge larva

Leys, Sally P. and Degnan, Bernard M. (2001) Cytological basis of photoresponsive behavior in a sponge larva. Biological Bulletin, 201 3: 323-338. doi:10.2307/1543611

Author Leys, Sally P.
Degnan, Bernard M.
Title Cytological basis of photoresponsive behavior in a sponge larva
Journal name Biological Bulletin   Check publisher's open access policy
ISSN 0006-3185
Publication date 2001-12-01
Sub-type Article (original research)
DOI 10.2307/1543611
Open Access Status Not yet assessed
Volume 201
Issue 3
Start page 323
End page 338
Total pages 16
Editor M. J. Greenberg
Place of publication Woods Hole, MA, USA
Publisher Marine Biological Laboratory
Language eng
Subject C1
270504 Invertebrate Biology
780105 Biological sciences
Abstract Ontogenetic changes in the photoresponse of larvae from the demosponge Reneira sp. were studied by analyzing the swimming paths of individual larvae exposed to diffuse white light. Larvae swam upward upon release from the adult, but were negatively phototactic until at least 12 hours after release. The larval photoreceptors are presumed to be a posterior ring of columnar monociliated epithelial cells that possess 120-mum-long cilia and pigment-filled protrusions. A sudden increase in light intensity caused these cilia to become rigidly straight. If the light intensity remained high, the cilia gradually bent over the pigmented vesicles in the adjacent cytoplasm, and thus covered one entire pole of the larva. The response was reversed upon a sudden decrease in light intensity. The ciliated cells were sensitive to changes in light intensity in larvae of all ages. This response is similar to the shadow response in tunicate larvae or the shading of the photoreceptor in Euglena and is postulated to allow the larvae to steer away from brighter light to darker areas, such as under coral rubble-the preferred site of the adult sponge on the reef flat. In the absence of a coordinating system in cellular sponges, the spatial organization and autonomous behavior of the pigmented posterior cells control the rapid responses to light shown by these larvae.
Keyword Biology
Marine & Freshwater Biology
Apical Sensory Organ
Metamorphic Competence
Swimming Behavior
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Biological Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 109 times in Thomson Reuters Web of Science Article | Citations
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Created: Wed, 15 Aug 2007, 02:52:17 EST