Related Experiment Video
Updated: Sep 12, 2025
10:34
A Swimming-Induced Zebrafish Exercise Apparatus for Versatile Training Approaches
Published on: October 18, 2024
1.4K
Teaching fish new tricks: Repeated exposure to a velocity barrier improves passage performance
Rachel Mb Crawford1,2, Eleanor M Gee2, Brendan J Hicks1
1School of Science, Environmental Research Institute, The University of Waikato, Hamilton, New Zealand.
Plos One
|August 8, 2025
Summary
Repeated exposure improved fish passage through high-speed water, suggesting learning enhances fish migration over barriers. Fish passage success increased significantly with daily practice over five days.
Area of Science:
- Ecology
- Animal Behavior
- Fish Biology
Background:
- Instream structures like culverts and dams disrupt fish migration.
- Fish passage success may depend on cognitive abilities and learning.
- Understanding these factors is crucial for effective fish passage solutions.
Purpose of the Study:
- To investigate the impact of repeated exposure on the passage performance of juvenile Galaxias maculatus.
- To determine if learning and cognition enhance fish ability to overcome velocity barriers.
Main Methods:
- Juvenile Galaxias maculatus were exposed to a high-speed raceway (0.45-0.5 m s-1) daily for five consecutive days.
- Passage performance, approach rates, and entry rates were recorded each day.
- Time-to-event analysis was used to assess changes in passage speed.
Main Results:
- The proportion of fish successfully passing the barrier increased significantly from 40% on Day 1 to 63% on Day 5.
- Fish passed the barrier significantly faster by Day 5 compared to Day 1.
- Repeated exposure did not improve approach or entry rates; fish length affected approach rates only.
Conclusions:
- Cognition and spatial memory likely improve passage performance through velocity barriers.
- Learning enhances fish ability to traverse challenging aquatic environments.
- Attraction flows may also be critical for successful fish passage outcomes.
