The structure and sensitivity of the eye of different life history stages of the ontogenetic migrator Gnathophausia ingens
Whitehill, E.A.G.; Frank, T.M.; Olds, M.K. (2009). The structure and sensitivity of the eye of different life history stages of the ontogenetic migrator Gnathophausia ingens. Mar. Biol. (Berl.) 156(6): 1347-1357. http://dx.doi.org/10.1007/s00227-009-1176-3
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, meer
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| Auteurs | | Top |
- Whitehill, E.A.G.
- Frank, T.M.
- Olds, M.K.
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| Abstract |
The structure and ultrastructure of the photoreceptors of several life history stages of the ontogenetically migrating lophogastrid crustacean Gnathophausia ingens were examined. The younger instars of this species live in a much brighter light field than the older instars, and this difference is reflected in differences in their visual systems. The shallowest free living individuals (instars 3 and 4) possess a superposition eye with almost no clear zone, which minimizes the light shared between ommatidia and reduces the sensitivity of the eye. A progression to superposition optics with a large clear zone, usually associated with night-active or deep-living species, occurs as the animals move deeper in the water column. Regional differences within the eye are also evident, with a largely nonexistent clear zone in the dorsal region and a large clear zone in the ventral region in the eyes of instar 5 animals, the first instar to move to deeper depths. The deepest living instars (10–12) possess superposition optics with a large clear zone throughout the eye, and are significantly more sensitive to light than the younger, shallower instars. |
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