Table A1.

A list and short behavioral description (ethogram) of the most common behavioral elements in paradise fish.

Element	Abbreviation	Description	Source
Active elements
Escape	ESC	Moving rapidly away from strong stimulus source.	[16]
Swim	SWI	Normal or fast locomotion with no special orientation.	[16]
Move	MOV	Slow, short-range locomotion with no special orientation.	[16]
Creeping	CRE	Slow, forward movement propelled only by the pectoral fin.	[16]
Staccato	STA	Quick starts and sudden stops, with no special orientation.	[16]
Leaping	LEP	Quick move, propelled by the caudal fin.	[16]
Erratic movement	ERA	Zig-zag locomotion performed on the bottom.	[16]
Jumping	JUP	Quick jump from a confined space, out of the water	[16]
Air gulping	A-G	Air gulping at the surface.	[16]
Air bubbling	A-B	Similar to air gulping but a few big bubbles are released through the gills or mouth. Most often associated with nest-building.	[16]
Approach	APR	Slow movement, oriented to a particular object.	[16]
Pick	PIC	Object picked with the jaw.	[16]
Back	BAC	Slow, backward locomotion.	[16]
Passive elements
Floating	FLO	The fish is floating 1–2 cm under the surface.	[16]
Hanging in midwater	HIM	The fish is floating > 2 cm under the surface.	[16]
Resting	RES	Fish rests at the bottom, with pectoral fins fanning slowly.	[16]
Freezing	FRZ	Fish is motionless at the bottom.	[16]
Freezing under the surface	FUS	Fish is periodically motionless near the surface, and gulps air in-between.	[16]
Social elements
Social orientation	ORI	Slow locomotion around a conspecific.	[16]
Oblique plan floating position 1	OBF	Submission posture, the body is 20–40 degrees inclined from the horizontal plane, only pectoral fins are fanning, other fins are closed.	[16]
Lateral head-head display 2,3	LHH	Fish are oriented in the same direction with one being slightly behind.	[18]
Lateral head-tail display 2,3	LHT	Fish (usually males) are oriented in opposite directions. Sometimes they also slowly start circling.	[18]
Lateral head-tail display with shaking 2	SHA	Similar to LHT but involves fast circling and descent to the bottom.	[18]
Frontal Display 2	FRD	Faces the opponent with unpaired fins extended. Body angle towards the opponent close to perpendicular.	[5,18]
Opercular Erection 2	OPE	Opercular erection, the opercular ocelli are visible. Usually performed by competing males during LHH, LHT or FRD.	[5,18]
Biting	BIT	The fish uses its jaws to inflict wounds by damaging the epidermis of the other fish	[5]
Charge	CHA	The fish swims fast in the direction of the opponent.	Described in the context of B. splendens [69]
Display at distance	DIS	Fish stay in head-tail position, with erected tailfin. Distance is larger than one body length.	[18]
Parallel swimming	PAS	The two fish swim closely to each other into the same direction.	[18]
Tail-beating	TAB	Occurs occasionally during LHH and LHT and consists of undulating thrusts of the tail towards the other fish	[5]
Mouth-lock	MOU	Occurs during intense fighting after FRD and OPE. Males lock their jaws and sink to the bottom of the tank. It can last from several seconds up to 2 min.	[18]
Lateral vibrating	VIB	Rapid undulatory movement that occurs when the pair is in head-to-head or head-to-tail position. Usually used by non-receptive females.	[5]
Circling	CIR	Male curves his body and slowly swims in a circle. Female follows with her snout at his dorsum.	[5]
Oblique plan movements	OBM	Median fins are commonly folded, the caudal fin often droops, and the fish often tilts laterally. Occasionally, the body may be tilted vertically, either upward or downward.	[5]
Vertical waggle	VEW	Low-frequency undulating movements of the caudal fin while the fish is in (near) vertical position. Often performed by receptive females.	[5]
Leading to the nest	LEN	After an LSD male swims slowly to the nest, with median fins erect.	[5]
Anabantoid embrace 4	ANE	Female moves into a U-shape flexture, with her snout protruding beyond the male’s dorsal fin. The male clasps the female, quivering of the body starts in both and they roll over. Genital pores move close to the bubble nest, gametes are released.	[5,7,11]
Swimming inhibition	SIN	After spawning, male releases the female and both become immobile, even start to sink.	[5]

¹ In Reference [16], this is called OBQ, but we wanted to differentiate it from OBF; ² In Reference [16], these are treated together as a single behavioral element, Display (DIP); ³ In Reference [5], these are treated together as a single behavioral element, Lateral Spread Display (LSD); ⁴ In Reference [5], this is called “Mounting, Clasping and Roll”.