SS1.08 Sensory Ecology, Neurophysiology and Behavior of Zooplankton
Date: Monday, June 10, 2002
Time: 4:30:00 PM
Location: Carson B
 
CohenJH, Duke University Marine Laboratory, Beaufort, NC, USA, jhc6@duke.edu
Forward, R, B, Duke University Marine Laboratory, Beaufort, NC, USA, rforward@duke.edu
 
COMPARATIVE SPECTRAL SENSITIVITIES OF VERTICALLY MIGRATING AND NON-MIGRATING MARINE CALANOID COPEPODS
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Copepod species that undergo nocturnal diel vertical migration are exposed to a narrow spectral distribution of light in deep water during the daytime, and are predicted to have spectral sensitivity maxima matching environmentally dominant wavelengths at depth to maximize photon capture (sensitivity hypothesis). For reverse migrators and non-migrating copepod species, spectral sensitivity maxima are predicted to coincide with the rather broad range of wavelengths available in their daytime surface habitat to maximize photon capture, and include sensitivity maxima offset from dominant wavelengths to aid in contrast vision (contrast hypothesis). The spectral absorption maxima of visual pigments were studied for nocturnal, reverse and non-migrating coastal marine calanoid copepod species using photobehavioral techniques. The test species included juvenile (CIV) and adult Centropages typicus, Anomalocera ornata, and Labidocera aestiva. Stimulation wavelengths ranged from 350nm to 740nm. Ontogenic and species differences in the observed spectral sensitivities of these species will be discussed with respect to their vertical migration patterns and the corresponding spectral composition of light in their daytime habitats.