Table 3.

Behavioural categories recorded for Siamese fighting fish (Betta splendens; n = 15) rotated between five tank treatments. The behavioural categories chosen were based on observed behaviours shown during the recordings themself. The total duration of each behaviour was recorded in seconds

Behaviour	Description
Resting	Motionless (fins not moving). Body in contact with a surface (ground, object, plant, side of tank, water surface).
Hovering	‘Hanging’ motionless in the water column, body not in contact with any surface. Pectoral fins typically moving.
Sinking or floating	Not actively swimming or moving fins, but fish sunk downward or floated upward.
Swimming	Irregular, non-stereotypic, varied routes and speeds.
Stereotypical swimming	Repetitive movements with no clear objective or outcome - e.g. pacing back and forth, circling. Considered once a movement has been performed 3 times in a row. Pacing is ‘broken’ if fish deviates significantly off course.
Interaction with the walls	Fish makes contact with a surface while moving, either the ground or the side walls. No time limit (e.g. doesn’t have to occur for 3 seconds to count). Does not include resting even if fish resting against a surface.
Out of view	Fish behaviour cannot be observed.
Nest building	Fish creates bubbles on the water surface and either hovers underneath or continuously puts mouth to water surface to build a nest.
Foraging	Fish appears to be searching for, then ‘nipping’ at small food items on the floor or on/under items.
Unsure	Behaviour cannot be confidently assigned into one of the above categories.