Behavioural tests for fish
We are performing behavioural test on zebrafish (Danio rerio) and rainbow trout (Oncorhynchus mykiss) on a routinely basis. Behavioural tests may be performed on other teleost species but in that case the tests may need to be modified according to species. Also, tests for rainbow trout need to be adjusted to the body size of the test fish.
Available tests
Aggression test
The test utilizes an arena with two compartments as well as a mirror in each compartment. As water can circulate between the two compartments, the fish are able to smell each other, but cannot otherwise interact. In this test, the number of attacks performed by each fish towards the mirror as well as the time until the first attack is carried out will be quantified.
Attraction to conspecifics
This test is carried out in an arena consisting of three compartments. One zebrafish is introduced to the middle while a number of other zebrafish are present in one of the other compartments. The remaining compartment is left empty. Behavior is tracked throughout the test, allowing analysis of interaction with the compartment containing the conspecifics.
Multivariate concentric square field for zebrafish
The multivariate concentric square field for zebrafish (zMCSF) is designed to screen a number of different behaviours such as exploration, risk-taking and shelter-seeking in a single test. The arena consists of several zones that are associated with different behaviours.
Novel object
An unfamiliar object (Lego brick) is introduced to the fish while in the open field arena. The reaction of the fish, whether it approaches and inspects the object or avoids it, is recorded along with activity. The test can be used together with an open field test in studies of boldness/shyness ("anxiety").
Novel tank diving test
The fish is introduced to an unfamiliar tank where its activity and swimming path is recorded. When introduced to a novel tank the fish immediately goes to the bottom and stays immobile. After a variable amount of time it will start to explore, first close to the bottom and later on also in the upper part of the tank. The time it takes for the fish to start exploring the upper part of the tank is used as an index of boldness/shyness.
Open field / exploratory behavior
The fish is introduced to an unfamiliar open arena where its behavior, activity and swimming path is recorded. Inactivity and/or swimming in the periphery of the arena reflect an anxiety like state whereas exploring the centre of the arena reflects boldness. The open field test can be combined with (1) novel object and (2) shelter seeking tests (see separate description).
Operant conditioning
UUBF can provide equipment to carry out many different types of operant tests, for example conditioned aversion tests in which the fish learn to associate a visual cue with mild electric shocks, leading them to avoid the area in which this cue is presented.
Resident-intruder test / Social dominance
The test is performed in specially designed fighting tanks. In these tanks (2 fish per tank) fish are kept visually isolated for 1-5 days. Following this acclimation period the partition separating two fish is removed and the fish are allowed to interact.
Scototaxis
In this test, the fish is placed in a tank with a darker and a brighter side. Zebrafish prefer darker spaces, but will gradually explore the brighter sida as well. This test is a good complement to the novel tank diving test.
Shelter seeking
A shelter consisting of a piece of opaque plastic is introduced to the fish while in the open field arena. Time spent under the shelter and latency to leave the shelter is recorded as a measure of boldness/shyness. The test can be performed in combination with open field and novel object tests.