POLAROTAXIS IN COPEPODS. II. THE ULTRASTRUCTURAL BASIS AND ECOLOGICAL SIGNIFICANCE OF POLARIZED LIGHT SENSITIVITY IN COPEPODS

¹ Bingham Laboratory, Yale University, New Haven, Conn. 06520

1. The ability of Cyclops vernalis to perceive polarized light has an ultrastructural basis in the presence of mutually perpendicular microvilli in its naupliar eye.

2. Laboratory investigations with several species of copepods were conducted to determine the extent of polarized light sensitivity in this group. Polarotaxis was not found to be universally present in copepods, but apparently depended on the presence of mutually perpendicular microvilli in the rhabdom of the naupliar eye.

3. Polarotaxis showed no correlation with the presence of a complex, rather than simple, naupliar eye.

4. The ability to perceive polarized light was more prominent in predatory than in herbivorous species, suggesting that its function might be to enable the copepods to discern distant objects more clearly, in addition to its role in orientation during vertical migration.

This article has been cited by other articles:

				I Novales Flamarique, H. Browman, M Belanger, and K Boxaspen Ontogenetic changes in visual sensitivity of the parasitic salmon louse Lepeophtheirus salmonis J. Exp. Biol., January 6, 2000; 203(11): 1649 - 1657. [Abstract] [PDF]