Table 4.

Key results of studies relating to sensory enrichment for laboratory zebrafish. Studies have been included where they have either addressed a preference (such as might be used to identify conditions which might promote welfare), or tested the effects of a condition intended to provide enrichment. Unless otherwise specified, all results here relate to the presence of the enrichment condition noted in the table compared with an absence of that condition.

Study	Enrichment	Indicator(s)	Effect(s)
[35]	Aquarium backing with blue seascape design on rear tank wall	Aggression	No effect
		Body length	No effect
		Fertilisation success	No effect
		Egg production	↑
[126]	Green, blue, yellow or red walls of tank	Preference (occupancy in enriched compartment)	Preference for green and blue over red and yellow.
[133]	Green, blue, yellow or red walls of tank	Preference (occupancy in enriched compartment)	Equal preference for red and green over yellow; aversion to blue
[128]	Green, red or blue doors in tank	Preference (choice of coloured door)	Preferred red over green; green over blue
[129]	Transparent, black, white, yellow, red or blue tanks	Anxiety	↓ in blue or black tanks compared with white or transparent tanks
		Cortisol	↓ in blue tanks compared with white tanks
[131]	Classical music (Vivaldi)	Anxiety	↓
		Cortisol	No effect
[132]	Water current intended to provide tactile stimulation	Fear response after exposure to alarm cue	↓
		Cortisol	↓
		Recovery of normal behaviour after exposure to alarm cue	↑
[82]	Airstone creating bubbles in water	Preference (occupancy in enriched compartment)	Preference for barren

↑ = increase; ↓ = decrease.