Table 1.
Study | Enrichment | Indicator(s) | Effect(s) |
---|---|---|---|
[45] | Presence of other zebrafish | Time spent near stimulus shoal | ↑ |
[46] | Presence of other zebrafish | Distance between members of experimental shoal when mixed wth stimulus shoal (higher distances indicate greater mixing of experimental and stimulus shoals and therefore stronger preference) | ↑ |
[47] | Presence of other zebrafish | Entries to compartment near stimulus shoal | ↑ for fish previously housed in groups or singly in barren tanks. No effect for experimental fish housed singly with an artificial plant. |
Time spent in compartment near stimulus shoal | ↑ for fish previously housed in groups or singly in barren tanks. No effect for experimental fish housed singly with an artificial plant. | ||
[48] | Presence of other zebrafish | Proportion of scan samples in which fish were near to stimulus fish or stimulus shoal | ↑ |
[49] | Choice between shoals | Time spent near larger shoal | ↑ |
[50] | Choice between shoals | Time spent near stimulus shoal | Males: preferred females over males, no preference between a mixed shoal and either a male or female shoal. No preference relating to shoal size. Females: no preferences relating to shoal composition. Preferred larger shoals over smaller shoals. |
[51] | Choice between shoals | Time spent near stimulus shoal | Males: preferred groups of 3 males over single males; preferred single females to groups of 3 females. Females: preferred larger shoals regardless of the sex. |
[53] | Presence of other zebrafish | Cortisol | ↓ |
[54] | Presence of other zebrafish | Cortisol | ↓ in grouped compared with paired zebrafish No effect between grouped and individual zebrafish |
Anxiety | ↓ | ||
Rate of recovery of normal behaviour after stressor | ↑ | ||
[55] | Presence of other zebrafish | Anxiety | ↓ |
[56] | Presence of other zebrafish | Anxiety | ↑ |
Serotonin | ↑ | ||
5HIAA | No effect | ||
Dopamine | No effect | ||
DOPAC | No effect | ||
[57] | Presence of other zebrafish (exposure to stimulus shoal after isolation) | Cortisol | ↑ |
Anxiety | No effect | ||
Serotonin | ↑ | ||
5HIAA | ↓ | ||
Dopamine | ↓ | ||
DOPAC | ↓ | ||
[58] | Presence of other zebrafish | Anxiety | ↑ |
Cortisol | ↑ | ||
[59] | Presence of other zebrafish | Cortisol (resting) | No effect |
Cortisol (after chasing with a net) | ↑ | ||
Cortisol (after predator exposure) | ↓ | ||
[60] | Presence of other zebrafish | Cortisol (resting) | No effect |
Cortisol (after chasing with a net) | ↑ | ||
[61] | Presence of other zebrafish | Cortisol (in fish raised in isolation) | No effect |
Cortisol (in group-raised fish after isolation) | ↓ | ||
Neurogenesis | ↑ | ||
[62] | Presence of other zebrafish | Latency to feed | ↓ |
Neophobia | ↓ | ||
[63] | Presence of other zebrafish | Cortisol (after chasing with a net) | ↑ |
Cortisol (after being moved to novel tank) | ↑ | ||
[71] | Housing in sexually segregated groups (as opposed to mixed-sex groups) | Fecundity | ↑ |
Egg viability | ↑ | ||
[72] | Housing in sexually segregated groups (as opposed to mixed-sex groups) | Weight | ↑ |
Cortisol | ↓ | ||
Inhibitory avoidance | ↑ | ||
Activity in open tank test | No effect |
↑ = increase; ↓ = decrease.