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Preference index supported by motivation tests in Nile tilapia
Caroline Marques Maia1, Gilson Luiz Volpato1
1Laboratory of Animal Physiology and Behavior, Institute of Biosciences (IB), UNESP, Botucatu, São Paulo, Brazil.
Plos One
|April 21, 2017
Summary
A new preference index (PI) reliably identifies animal preferences by comparing choice tests with motivation tests. Nile tilapia fish showed consistent motivation for preferred colors like blue and green, avoiding yellow and red.
Area of Science:
- Animal Behavior
- Aquaculture
- Ethology
Background:
- Understanding animal preferences is crucial for optimizing captive rearing environments.
- Preference tests traditionally measure approach frequency or proximity time.
- A novel preference index (PI) was developed to distinguish sustained preferences from transient responses.
Purpose of the Study:
- To compare the validity of the preference index (PI) against motivation tests in Nile tilapia.
- To assess the reliability of the PI in identifying individual animal preferences.
Main Methods:
- Choice tests were conducted over seven days with 34 Nile tilapia in compartments of varying colors.
- The preference index (PI) was used to determine preferred and non-preferred colors for each fish.
- Motivation was assessed by measuring the effort (door touches) fish expended to access compartments.
Main Results:
- Individual Nile tilapia exhibited distinct color preferences.
- Fish motivation levels correlated with their identified preferences, showing greater effort for preferred colors.
- On average, fish preferred blue and green, while avoiding yellow and red.
Conclusions:
- The preference index (PI) is a reliable tool for assessing animal preferences in research and animal husbandry.
- Results support the PI's ability to quantify preference intensity and differentiate it from momentary reactions.
- The study validates the PI's utility in establishing optimal conditions for animal welfare.
