Single target acuity for moving targets in the common sunfish (Lepomis gibbosus)

TL;DR

The study shows that common sunfish can see moving targets as clearly as stationary ones.

Contribution

The study reveals that motion does not affect the sunfish's visual acuity for small targets.

Findings

The single target acuity for moving targets was 0.144±0.002 degrees.

Sunfish showed equal acuity for moving and stationary targets.

The results add to the understanding of fish vision and grating acuity data.

Abstract

The common sunfish (Lepomis gibbosus) likely relies on vision for many vital behaviors that require the perception of small objects such as detection of prey items or body marks of conspecifics. A previous study documented the single target acuity (STA) for stationary targets. Under many, if not most, circumstances, however, objects of interest are moving, which is why the current study tested the effect of the ecologically relevant parameter motion on sunfish STA. The STA was determined in two sunfish for targets moving randomly at a velocity of 3.4 deg/s. The STA for moving targets (0.144±0.002 deg) was equal to the STA for stationary targets obtained from the same fish individuals under the experimental conditions of this/the previous study. Our results contribute to a comprehensive understanding of fish vision, extending the large data set available on grating acuity.

Summary: This study reveals that the common sunfish's visual system perceives moving targets with equal precision as stationary targets.

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