Visual Acuity in Ray-Finned Fishes Correlates with Eye Size and Habitat

Authors

Eleanor M. Caves, Duke University
Tracey Sutton, Nova Southeastern UniversityFollow
Sonke Johnsen, Duke University

ORCID

0000-0002-5280-7071

Document Type

Article

Publication Title

Journal of Experimental Biology

ISSN

0022-0949

Publication Date

5-1-2017

Abstract

Visual acuity (the ability to resolve spatial detail) is highly variable across fishes. However, little is known about the evolutionary pressures underlying this variation. We reviewed published literature to create an acuity database for 159 species of ray-finned fishes (Actinopterygii). Within a subset of those species for which we had phylogenetic information and anatomically measured acuity data (n=81), we examined relationships between acuity and both morphological (eye size and body size) and ecological (light level, water turbidity, habitat spatial complexity and diet) variables. Acuity was significantly correlated with eye size (P<0.001); a weaker correlation with body size occurred via a correlation between eye and body size (P<0.001). Acuity decreased as light level decreased and turbidity increased; however, these decreases resulted from fishes in dark or murky environments having smaller eyes and bodies than those in bright or clear environments. We also found significantly lower acuity in horizon-dominated habitats than in featureless or complex habitats. Higher acuity in featureless habitats is likely due to species having absolutely larger eyes and bodies in that environment, though eye size relative to body size is not significantly different from that in complex environments. Controlling for relative eye size, we found that species in complex environments have even higher acuity than predicted. We found no relationship between visual acuity and diet. Our results show that eye size is a primary factor underlying variation in fish acuity. We additionally show that habitat type is an important ecological factor that correlates with acuity in certain species.

DOI

10.1242/jeb.151183

Volume

220

Issue

9

First Page

1586

Last Page

1596

Comments

©2017. Published by The Company of Biologists Ltd

NSUWorks Citation

Eleanor M. Caves, Tracey Sutton, and Sonke Johnsen. 2017. Visual Acuity in Ray-Finned Fishes Correlates with Eye Size and Habitat .Journal of Experimental Biology , (9) : 1586 -1596. https://nsuworks.nova.edu/occ_facarticles/816.