Table 1.

Behavioral tests used in depression-/anxiety-like behavior assessment in zebrafish.

Behavioral Test	Test Description	Ref.
Novel tank test (NTT)	Similar to the OFT in rodents. Zebrafish are placed in a tank, divided into two equal horizontal parts and the following parameters are measured: the time spent in upper and lower parts of the tank, number of entries to the upper part, latency to enter the upper part, freezing time, irregular movements, immobility, swimming speed, and travelled distance.	[33,51,52]
Open field test (OFT)	Similar to the OFT in rodents. Zebrafish are placed in a novel tank and the following parameters are measured: thigmotaxis (peripheral swimming) and exploration behavior.	[55,56,66]
Light/dark test	Similar to the light/dark test in rodents. The test evaluates scototaxis (preference for dark environments) by recording latency to enter a white half of the tank, time spent in the white half, and number of entries to the white half.	[58,67,68]
Zebrafish tail immobilization test (ZTI)	Similar to the forced swim test and the tail suspension test in rodents, which detect the despair-like phenotype. The most important parameters are overall activity, overall mobility, time spent mobile or active, and number of activity episodes.	[61]
Shoaling test	Similar to the social behavior test in rodents. The test measures an influence of the anxious state on social interactions. The most important parameters are distance between subjects and height of exploration.	[56,62,63]
Social preference test	Similar to the social behavior test in rodents. In this test, Danio rerio behavior towards their conspecifics is observed. The time spent by the observed fish in the areas proximal to the social stimulus is measured.	[64]
Novel object approaching	Similar to novelty exposure task in rodents. In this test a novel object is introduced into a tank well-known for a given subject, and the following parameters are measured: latency to approach to a new object, time spent in the vicinity of a new object, thigmotaxis, and number of freezing episodes and their duration.	[56,69,70]
Predator avoidance	Partially similar to predator avoidance in rodents. In this test, a natural predator of zebrafish is introduced into a tank well known for a given subject, and the following parameters related to avoidance and fear are measured: distance between the predator and a tested subject, geotaxis (diving towards the bottom of the tank), activity (i.e., average speed), turn angle, number of freezing episodes, and time spent frozen.	[56,71]