The structure and sensitivity of the eye of different life history stages of the ontogenetic migrator Gnathophausia ingens |
| |
Authors: | Elizabeth A G Whitehill Tamara M Frank and Mary K Olds |
| |
Institution: | (1) Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC 29634, USA;(2) Center for Ocean Exploration and Deep-sea Research, Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 US 1 North, Ft. Pierce, FL 34946, USA;(3) Grice Marine Laboratory, College of Charleston, 205 Ft. Johnson Rd, Charleston, SC 29412, USA |
| |
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. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|