Abstract
Species of the freshwater planarian genus Polycelis have a variable number of eyes in the head, typically more than a hundred. To elucidate the mechanisms determining the number of eyes, we investigated the relation between eye number and body length in Polycelis sapporo (Ijima & Kaburaki), a non-fissioning species, and P. auriculata Ijima & Kaburaki, a fissioning species. In P. sapporo reared at 7–8 °C, a positive correlation existed between number of eyes and body length. Eye number decreased with starvation. A similar correlation was true of P. auriculata. In specimens of P. auriculata undergoing regeneration, the rate of eye formation was higher in newly formed heads originating from larger tail-pieces than in those from smaller pieces. As a head regenerated from a tail piece or as the body size increased with feeding, the number of eyes increased. These results suggest that the number of eyes in an individual of Polycelis is determined by body length. The fine structure of the photoreceptor and pigment cells in the eyes of P. auriculata is similar to that of comparable cells in the pair of eyes in Dugesia despite the difference in the number of cells comprising an eye.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Carpenter, K. S., M. Morita & J. B. Best, 1974. Ultrastructure of the photoreceptor of the planarian Dugesia dorotocephala. I. Normal eye. Cell Tiss. Res. 148: 143–158.
Kawakatsu, M., 1974. Further studies on the vertical distribution of freshwater planarians in the Japanese islands. In N. W. Riser & M. P. Morse (eds), Biology of the Turbellaria. McGraw-Hill, New York: 291–338.
Kenk, R., 1935. Studies on Virginian triclads. J. Elisha Mitchell Sci. Soc. 51: 79–125.
Kishida, Y., 1965. The ultrastructure of the eye in Dugesia japonica. I. The distal portion of the visual cell. Zool. Mag. (Tokyo) 74: 149–155. [In Japanese with English abstract]
Kishida, Y., 1966. The ultrastructure of the eye in Dugesia japonica. II. The pigment cell layer. Zool. Mag. (Tokyo) 75: 40–46. [In Japanese with English abstract]
Kishida, Y., 1967. Electron microscopic studies on the planarian eye. I. Fine structures of the normal eye. Sci. Rep. Kanazawa Univ. 12: 75–110.
Sopott-Ehlers, B., 1991. Comparative morphology of photoreceptors in free-living plathe1minths-a survey. Hydrobiologia 227/Dev. HydroBiol. 69: 231–239.
Teshirogi, W., S. Ishida & H. Yamazaki, 1977. Regenerative capacities of transverse pieces in the two species of freshwater planarian, Dendrocoelopsis lactea and Polycelis sapporo. Sci. Rep. Hirosaki Univ. 24: 55–72.
Teshirogi, W., S. Ishida & H. Yamazaki, 1978. Regenerative capacities of transverse pieces in the two species of freshwater planarians, Dendrocoelopsis lactea and Polycelis sapporo from Aomori Prefecture, especially compared with those of the same species from Hokkaidô. Zool. Mag. (Tokyo) 87: 262–273. [In Japanese with English abstract]
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1991 Kluwer Academic Publishers
About this paper
Cite this paper
Aikawa, M., Shimozawa, A. (1991). The multiple eyes of Polycelis. 1. Relation between the number of eyes and body length. In: Tyler, S. (eds) Turbellarian Biology. Developments in Hydrobiology 69, vol 69. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-2775-2_37
Download citation
DOI: https://doi.org/10.1007/978-94-011-2775-2_37
Publisher Name: Springer, Dordrecht
Print ISBN: 978-0-7923-1373-1
Online ISBN: 978-94-011-2775-2
eBook Packages: Springer Book Archive