Differences in brain morphology of brown trout across stream, lake, and hatchery environments

Závorka, L., Koene, J. P., Armstrong, T. A., Fehlinger, L. and Adams, C. E. (2022) Differences in brain morphology of brown trout across stream, lake, and hatchery environments. Ecology and Evolution, 12(3), e8684. (doi: 10.1002/ece3.8684)

Abstract

It has been suggested that a trade‐off between cognitive capacity and developmental costs may drive brain size and morphology across fish species, but this pattern is less well explored at the intraspecific level. Physical habitat complexity has been proposed as a key selection pressure on cognitive capacity that shapes brain morphology of fishes. In this study, we compared brain morphology of brown trout, Salmo trutta, from stream, lake, and hatchery environments, which generally differ in physical complexity ranging from low habitat complexity in the hatchery to high habitat complexity in streams and intermediate complexity in lakes. We found that brain size, and the size of optic tectum and telencephalon differed across the three habitats, both being largest in lake fish with a tendency to be smaller in the stream compared to hatchery fish. Therefore, our findings do not support the hypothesis that in brown trout the volume of brain and its regions important for navigation and decision‐making increases in physically complex habitats. We suggest that the observed differences in brain size might be associated with diet quality and habitat‐specific behavioral adaptations rather than physical habitat complexity.

• Item Type: Articles
• Additional Information: LZ was funded by the Austrian Science Fund, FWF, Lise Meitner Program (Project M2742 BBL). JPK was funded by the FSBI PhD Studentship
• Keywords: Behavioural ecology, evolutionary ecology, nature notes, animal cognition, hatchery environment, intraspecific variably, Omega‐3 long‐chain fatty acids, trophic interactions.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Koene, Peter and Zavorka, Dr Libor and Armstrong, Miss Tiffany and Adams, Professor Colin

Creator Roles

Závorka, L.: Conceptualization, Data curation, Formal analysis, Funding acquisition, Methodology, Project administration, Resources, Visualization, Writing – original draft
Koene, J. P.: Conceptualization, Investigation, Methodology, Validation, Visualization, Writing – review and editing
Armstrong, T. A.: Data curation, Methodology, Resources, Software, Validation, Writing – review and editing
Adams, C. E.: Conceptualization, Funding acquisition, Investigation, Methodology, Resources, Writing – review and editing

• Authors: Závorka, L., Koene, J. P., Armstrong, T. A., Fehlinger, L., and Adams, C. E.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Ecology and Evolution
• Publisher: Wiley
• ISSN: 2045-7758
• ISSN (Online): 2045-7758
• Published Online: 08 March 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Ecology and Evolution 12(3): e8684
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.6084/m9.figshare.19152779