Hydrologic regimes as potential drivers of morphologic divergence in fish

Evolutionary Ecology
By:  and 

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Abstract

Fishes often exhibit phenotypic divergence across gradients of abiotic and biotic selective pressures. In streams, many of the known selective pressures driving phenotypic differentiation are largely influenced by hydrologic regimes. Because flow regimes drive so many attributes of lotic systems, we hypothesized fish exhibit phenotypic divergence among streams with different flow regimes. We used a comparative field study to investigate the morphological divergence of Campostoma anomalom (central stonerollers) among streams characterized by highly variable, intermittent flow regimes and streams characterized by relatively stable, groundwater flow regimes. We also conducted a mesocosm experiment to compare the plastic effects of one component of flow regimes, water velocity, on morphology of fish from different flow regimes. We observed differences in shape between flow regimes likely driven by differences in allometric growth patterns. Although we observed differences in morphology across flow regimes in the field, C. anomalum did not exhibit morphologic plasticity in response to water velocity alone. This study contributes to the understanding of how complex environmental factors drive phenotypic divergence and may provide insight into the evolutionary consequences of disrupting natural hydrologic patterns, which are increasingly threatened by climate change and anthropogenic alterations.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Hydrologic regimes as potential drivers of morphologic divergence in fish
Series title Evolutionary Ecology
DOI 10.1007/s10682-017-9897-0
Volume 31
Issue 4
Year Published 2017
Language English
Publisher Springer International
Contributing office(s) Coop Res Unit Atlanta
Description 14 p.
First page 517
Last page 531