Comparative visual function in five sciaenid fishes inhabiting Chesapeake Bay

Area of Science:

• Ichthyology
• Sensory Ecology
• Aquatic Biology

Background:

• Sciaenid fishes are vital to commercial and recreational fisheries in North Atlantic coastal and estuarine waters.
• Optimal visual performance is challenging in these dynamic, photic environments.
• Despite ecological differentiation, sciaenid visual systems remain largely uncharacterized.

Purpose of the Study:

• To characterize the visual system properties of five common sciaenid species from Chesapeake Bay.
• To investigate how visual sensitivity, temporal properties, and spectral characteristics relate to sciaenid ecomorphology and habitat.
• To assess sciaenid visual adaptations to their native photoclimate.

Main Methods:

• Electroretinographic techniques were employed to measure visual system parameters.
• Experiments included white light sensitivity (V/logI) and flicker fusion frequency.
• Spectral sensitivities were analyzed, with attention to diel variations and ultraviolet responses.

Main Results:

• Benthic sciaenids showed higher light sensitivities and broader dynamic ranges than pelagic species.
• Significant interspecific differences in flicker fusion frequency correlated with habitat and lifestyle.
• Spectral sensitivities generally ranged from 400-610 nm, with weakfish and Atlantic croaker exhibiting diel differences.

Conclusions:

• Sciaenid visual systems are well-adapted to the variable light conditions of coastal and estuarine environments.
• Anthropogenic water quality degradation poses a challenge to these visual adaptations.
• Characterizing sciaenid visual function is crucial for managing these important aquatic fauna.