title: Comparative visual ecophysiology of mid-Atlantic temperate reef fishes.
abstract: The absolute light sensitivities, temporal properties, and spectral sensitivities of the visual systems of three mid-Atlantic temperate reef fishes (Atlantic spadefish [Ephippidae: Chaetodipterus faber], tautog [Labridae: Tautoga onitis], and black sea bass [Serranidae: Centropristis striata]) were studied via electroretinography (ERG). Pelagic Atlantic spadefish exhibited higher temporal resolution but a narrower dynamic range than the two more demersal foragers. The higher luminous sensitivities of tautog and black sea bass were similar to other benthic and demersal coastal mid-Atlantic fishes. Flicker fusion frequency experiments revealed significant interspecific differences at maximum intensities that correlated with lifestyle and habitat. Spectral responses of the three species spanned 400-610&emsp14;nm, with high likelihood of cone dichromacy providing the basis for color and contrast discrimination. Significant day-night differences in spectral responses were evident in spadefish and black sea bass but not tautog, a labrid with characteristic structure-associated nocturnal torpor. Atlantic spadefish responded to a wider range of wavelengths than did deeper-dwelling tautog or black sea bass. Collectively, these results suggest that temperate reef-associated fishes are well-adapted to their gradient of brighter to dimmer photoclimates, representative of their unique ecologies and life histories. Continuing anthropogenic degradation of water quality in coastal environments, at a pace faster than the evolution of visual systems, may however impede visual foraging and reproductive signaling in temperate reef fishes.
authors.affiliation: Department of Marine and Environmental Science, Hampton University, Hampton, VA 23664, USA.
authors.forename: Andrij Z
authors.initials: AZ
authors.lastname: Horodysky
authors.forename: Richard W
authors.initials: RW
authors.lastname: Brill
authors.forename: Kendyl C
authors.initials: KC
authors.lastname: Crawford
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Seagroves
authors.forename: Andrea K
authors.initials: AK
authors.lastname: Johnson
keywords: Electroretinography; Fish; Flicker fusion frequency; Spectral sensitivity; Temperate reef; Visual ecology