Display vigour and subsequent fight performance in the siamese fighting fish, betta splendens

Behaviourd Elsevier

Processes,

1I (1985) 113-121

113

DISPLAY VIGOUR AND SUBSEQUENT FIGHT PERFORMANCE FIGHTING FISH, BETTA SPLENDENS.

IN THE SIAMESE

C. S. EVANS’ ept. of Zoology, University of Cambridge, Cambridge, England f Now at Dept. of Psychology, Washington University, St. Louis, MO 63130, USA (Accepted

13

June

1984)

ABSTRACT Evans, C. S., 1985. Display vigour and subsequent fighting fish, Betta splendens. Behav. Processes

fight performance L1 : 113 - 13 1.

The display of 24 individual male Siamese fighting conspecific was measured, and the fish were then placed 12 pairs, the outcome of the aggressive interaction which cover erection durations obtained in the pre-fight isolate result for theories of display function are discussed.

in the Siamese

fish to an unresponsive stimulus together in pairs. For 11of the ensued was predicted by the gill tests. The implications of this

INTRODUCTION The behaviour of many studies,

of the Siamese

and the sequence

fighting

of events

between

conspecifics

has been described

together

will undergo

profound

characteristic

orientation,

by a stereotyped mouthlocking, & Peeke,

occurring

in detail

displays,

considerable

damage

(Braddock

mirrors,

behaviours

or live fish behind a barrier

Bols, 1977; Hogan & Bols, 1980; Bronstein, display eliciting described

techniques

a correlation

as a pre-fight

with subsequent

that the fish which display

encounters

with conspecifics

antagonists,

into biting and

& Braddock,

1955; Klein, Figler

(Thompson,

(Baenninger,

subsequently

proved

fishes which had the opportunity they were p!aced tc;ether,

relationships

1963, 1969; Simpson,

have employed

measurement

behaviour,

of agonistic

fight outcome.

For example, to mirrors

1975; these

and have

it has been

are dominant

in later

1968; Meliska et al., 1975) and that the fishes to a barrier

which separated

to be dominant to display

them from their

in seven out of eight cases. to a mirror,

than its pairmember.

after

five minutes

the winner-to-be

It has also been reported

to display to both mirrors took less time to cstahlich

and their future

opponents

rfnminant!sllhordinate

(IMeliska, 1974 in Meliska & Meliska, 1976; Meliska et al., 1980).

0376-6357/85/$03.30

1966,

1983). Some investigators

in the same tank, and allowed

to face its image more often

fish by means

1970; Rhoad, Kalat & Klopfer,

Simpson (1968) has shown that in five pairs of fish separated

of interaction

before

This is usually followed

escalates

may be evoked in isolated

most vigourously

the most time in close proximity

Similarly, turned

their fins, and adopt a

1976).

of models,

future

interaction

1968). Two males placed

spread

which often

1968; Hogan, 1968; Hogan & Roper, 1978; Baeninger,

spending

has been the subject

during an aggressive

(Simpson,

in colouration,

of threat

Many or all of these agonistic

reported

splendens)

often at right angles to each other.

sequence inflicting

changes

fish (Betta

Q 1985 Elsevier Science Publishers B.V. (biomedical

Division)

that

114

These findings ing aggressive

are strikingly

interactions

between

Brock et al., 1979; Clutton-Brock often be predicted

similar

to those reported

rutting

red deer stags (Cervus elaphus

& Albon, 1979). The outcome

by the rate at which the opposing

that this is a case of “honest advertisement”, highly correlated displays

with fighting

by Clutton-Brock,

ability.

describ-

1.) (Clutton-

of these contests

males roar, and the authors

where an energetically

Similar suggestions

since Simpson (1968) has shown that the effect

suggest

costly signal is

have been made about visual

in fish (Zahavi, 1981). These models may also apply to the aggressive

Bettas,

can

display of

of one fish’s behaviour

on another

is highly predictable. If Bettas their fighting

may profitably

prowess

vigour to a non-reactive before

be viewed as disseminating

by means of their threat stimulus

they are introduced

Several

study examined

fight outcome,

and subordinate of mirrors

fish.

to provide

objections

centre

authors

should “bluff” and conceal

affect

stimulus

properties

of isolate

of the aggressive

encounter

the problems

feedback

for

on both dominant

presented

by the use

1975; Peeke & Peeke,

19701, their

the fish being tested

the test fish’s display in an uncontrolled over time as a result of fatigue

some of the problems

that this stimulus

display rates

obtains

with this

which can see the test fish or their own mirror image will

study was designed

way, and may change

or habituation.

of mirror and model designs.

also differs

from the natural

situation

and consequently

their

The apparatus

to allow the test fish to view a non-displaying

to the test fish display,

1983, personal

accuracy

have described

on the inappropriate

similarly

“indifferent”

of a pair

have argued that this should

animals

stimuli (Rhoad, Kalat & Klopfer,

Live conspecifics

avoiding

the winning member

authors

the predictive

and the effects

Several

method.

the present

about

to win fights (Dawkins & Krebs, 1978).

The present subsequent

information

then it follows that display

could be used to predict

to each other.

not be the case, and that under some circumstances their potential

accurate

displays,

used

Betta,

in

thus

It should be noted, however,

because

the stimulus

fish is

is not driven away (Bronstein,

communication).

METHODS Subjects Twenty-four maintained

male Betta

in jars, visually

were fed freeze-dried apparatus

contained

splendens

isolated,

were obtained

with the temperature

Tubifex worms once daily. chloamphenicol

(an antibiotic)

as adults from local dealers, regulated

and

at 27% f 1°C. Fish

The water in both the jars and the test at 2.4 mg. per litre.

Apparatus A plastic smaller

tank

35 rm.

Y 7lr K -m.

Y 7fl rm.

wz15

divided intn Tao C-r;.-r+ments,

of which (12.5 cm. x 24.5 cm. x 20 cm.) housed the stimulus

the subject

fish.

The partition

consisted

of a “sandwich”

of Plexiglas

the

fish and the larger of sheet containing

115

two sheets of “opposite” bly was held together

one-way

plastic

(Rank Strand Electric

by means of brass bolts at the corners,

The tank was then filled

with aged tap water,

was added to the bottom.

The stimulus

from the observer, dark.

arranged

observer,

whereas

be a black wall. observer

fish was then placed

was illuminated

the stimulus

from the stimulus It was necessary

end) to prevent

after

Data were recorded well of Glasgow,

into place.

in the smaller

compartment

of the study. by two 6OW lamps at the opposite

fish was visible,

end

The room was otherwise

both to the subject

fish side of the apparatus,

the partition

and the appeared

to

to lightly sand the sides of the tank (other than the

the fish seeing their reflected

the same size as the test apparatus both tanks was changed

and cemented

at an angle of 45’ to the partition.

Under these conditions

The whole assem-

and a 4 cm deep layer of washed gravel

of the tank, and was housed there for the duration During tests the apparatus

Ltd.).

images.

was used for aggressive

A second

plastic

interactions.

tank of

The water in

each group of three pairs had been run.

on a 12 pen event recorder

made by Edgoumbe

with a paper speed of 2.5 cm. per minute.

was done with a Pye Instruments

Peebles

Observation

Both-

period timing

stopclock.

Procedure Each fish was allowed test), and was then placed nant/subordinate tested

relationship

with the stimulus

to display to the non-responding

together

with its pairmember

was established

fish 24 hours after

(fight).

as Thompson

for evoking to control

and Sturm (1965) have pointed

display in Bettas. for variation

necessitated

Further,

in activity

testing

(Hogan,

running the experiment

tank until a domi-

Both pairmembers

the fight (post-fight

Fish which were to be paired were matched possible,

stimulus fish (pre-fight

in a separate

were then re-

test).

for size and colouration out the importance

was carried

as far as

of these factors

out at the same time each day

1961 in Hogan, 1968); this latter procedure

as a series of replications,

using three pairs at a

time. The first of the fish to be paired was introduced the test apparatus

and observed

this was characterised colouration display

and spreading

toward

of the dorsal,

within ten minutes were removed.

the trauma associated which subsequently fish immediately.

later paired,

with introduction

proved

ventral

This flexible

and returned

erection

in the distance

of

the onset of display behaviour, fish, a deepening

and caudal

fins.

prevented

was necessary

since

even those fish

display from reacting

to its home jar; the second

of body

Fish which did not

initial period

into the tank often

to have a very vigourous

was then tested

Gill cover

following

the stimulus

At the end of the ten minute test period

from the apparatus

increase

for ten minutes

by orientation

into the large compartment

to the stimulus

the first fish was removed fish, with which the first was

in the same way.

(GCE) was selected between

as the index of threat display.

the distal edge of the operculum

GCE is an

and the body, which is

116

often accompanied

by extension

of the branchiostegal

membranes

end of a bout of GCE is marked by a sudden movement toward the body even if they are not completely a number of authors Figler & Peeke,

to describe

aggressive

1976; Braddock

known to occur in most other anabantid Simpscn (1968) has pointed greater

duration

two female

The observer

Ten minutes removed

after

caused both individuals ists.

the conclusion to display,

Braddock, returned

of lateral

of pre-fight

testing

together

procedure

and were tested

between

fish GCE bouts

both paired

fish were

led to biting by one or both antagonbecoming

colouration

at the approach

to their home jars as soon as a definite

been established,

and a

in the large tank; this invariably

and sometimes

fleeing

1957). Further,

recorder.

lines of the original

1955) and repeatedly

(Forselius,

of subject

The end of the fight was marked by the subordinate

with the appearance

1968; Klein,

during an interaction

the duration

to the event

from their home jars and placed

has been used by

(e.g., Simpson,

with facing the opponent,

the winner-to-be

(GCED), using a key panel connected

This movement

fish, and some cichlids

recorded

1968). The

1955; Lobb & McCain, 1976), and is also

out that GCE coincides

of GCE characterises

Bettas.

closed.

display in Bettas

& Braddock,

(Simpson,

of the distal edge of the opercula

extremely

of the dominant.

dominant/subordinate

with the stimulus

pale, often

(e.g., Braddock

&

The fish were relationship

had

fish 24 hours later using the same

asbefore.

RESULTS Fish can be compared test periods. was greater

according

to GCED during the 10 minute pre- and post-fight

In 11out of 12 pairs, the display duration than that of the future

subordinate

of the future

pairmember

dominant

(binomial

pairmember

test 2-tailed;

P =

.016) (see Table I). Further, interactions

the group of fish which subsequently

had a greater

group of future although

subordinate

hours after

ing to the test stimulus displaying,

vigourously. ranked before

appear

(Table I). The effect

unexpectedly

z = 3.059,s

than the

= 19, E = .0022)

the two groups.

on dominants

of changes

fish had ceased

was more variable,

lower values than pre-fight

of non-displaying

none of the fin spreading

to correlate

in aggressive

testing

displaythree

and two displayed

if the dominant

more

GCED scores are

the fight experience.

into the apparatus

While pre-fight

test 2-tailed;

the fight I1 of the 12 subordinate

There is no obvious pattern and after

proved to be dominant fish during pre-fight

overlap between

seven produced

The behaviour introduction showed

fish (Mann-Whitney

there was considerable

Twenty-four ceased

display to the stimulus

these

fish in the post-fight fish frequently

or colour changes

oriented

long interactions

is of interest;

toward

of fight outcome,

Some of the least vigourously

when placed with their pairmembers,

on

the stimulus,

which are associated

test data were a good predictor with fight duration.

tests

but

with display. they do not displaying

whereas

fish had

some much

117

more vigourous definitive

displayers

subordinate

capitulated

behaviour

after

a short time.

It was also noted that

was never seen immediately

or mouthlocking,

but that a period of individual

quite ephemeral,

was always the last event in the interaction.

after

or mutual display,

an exchange although

of bites

sometimes

TABLE 1 A Comparison per minute)

of pre- and post-fight for both dominant

scores (mean seconds

GCED

and subordinate

Pre-Fight

pairmembers.

Test

Post-Fight

Subordinate

Dominant

Dominant

Test Subordinate

G

27.5

J

4.6

G

0

J

u

26.7

V

12.3

U

18.5

V

0

F

24.8

D

11.1

F

18.6

D

4.0

C

21.4

E

0

C

10.8

E

0

Q

20.5

R

6.6

Q

0

R

0

K

19.6

L

16.3

x

10.1

L

0

0

X

14.9

W

0

X

6.6

W

0

Z

14.4

Y

2.3

Z

34.1

Y

0

T

12.4

S

2.9

T

7.1

S

0

N

11.2

M

18.6

N

6.5

M

0

P

10.9

0

4.2

P

0

0

0

H

6.5

I

0

H

7.9

I

0

Note.

N and M were deviant

in that the future

subordinate

had the greater

pre-fight

test

score.

DISCUSSION The remarkable in agreement

predictive

et al (1975) using the future that these findings to elicit reasonable by-second

dispiay.

despite

If this information

to propose matching

of pre-fight

by Baeninger

pair members

are similar

Hence the aggressive

as stimuli

considerable

display of Bettas

to some extent as measured

is

and Meliska

it should be noted

in the stimuli employed

by human observers,

it seems

to the fish even in the second1980. pers. comm.).

by GCED would seem to be a candi-

class of signals indicative

holding power (RHP) (Glutton-Brock

for fight outcome

for each other; differences

is so easily garnered

that it is available

test scores

(1968) using mirror stimuli,

of GCE which occurs during a fight (Simpson,

date for the “honest advertisment” resource

accuracy

with the data reported

of fighting

& Albon, 1979; Parker,

ability

or

1974; Maynard-Smith

118

& Parker, species

1976) which now appear

(Davies & Halliday, A few observations

evidence

favouring

“broadside” observed

postures

for information

transfer,

the appearance

interpreted preceded

fleeing

Recent

between similarity although

(Zahavi,

statement

if minimally required

they are direct

effect

Finally,

a confusion

and true “bluffing”

the post-fight

between

than subordinates,

fish obtained

in the present

of the fight experience.

of the varying

low rates of valid,

amounts

it has been suggested of aggressive

1973). This idea has been extended (1975) who have suggested “fish whose aggressive

responding

habituates

to perform”;

high rates of tail

Baeninger

reinforced

and the relative

incurred

might determine

a similar

be interpreted

to the large range of fight by individual

“is the major process

territorial

(1970) has

display rates of domin-

these data cannot

corresponding

1955).

by the presentation

study would seem to reflect

conspecifics”

by Meliska, Meliska, Hoyenga,

that habituation

ability

are often hard to

& Braddock,

test results.

of damage

between

of fighting

and hence costly involving

response

that habituation

behaviour

which is accurate,

used in assessment

However,

levels of fatigue

has

(Hinde, 1981). That is, the

1968; Braddock

an operant

citing the

This approach

with regard to the display of Bettas

trials of strength

to interpret

and

the

that the contest

with the exaggeration

(Simpson,

and the uncontrolled

the reduction

the end of an interaction.

alternations

of a mirror image more often

because

in 25 of the 35 pairs studied.

fish is plainly exhausting,

fish will perform

ant and subordinate

& Braddock

GCE), immediately

both bluff and assessment”

that “displays

or indirect

fighting

It is more difficult

differential

release

they also suggest

shown that dominant

durations,

“involves

should not be confused

and rapid position

may also be

Dawkins & Krebs (1978) have suggested

The Dawkins and Krebs position

the display of Siamese

in part on an

with Braddock

“will stay and can display at least this vigourously”,

because

bluff because beating

and is in agreement

1981) and seems to reflect

informative,

sequence

dealing with the topic of animal signals in general

information

by “bluff”.

is puzzling

depends

in the 12 pairs studied

by one pairmember

in Betta spendens

non-specific,

“facing” and

of roaring

temporal

(an index of display including

of display rates until just before

been criticised

between

(Dawkins and Krebs, 1978; Hinde, 1981) have discussed

of “bluff” or “deceit”. conspecifics

general

articles

in particular

alternate

During the

that display was always the element

behaviour

terms,

and colour changes

to be circumstantial

seem to be a near-optimal

The observation

transfer

of several

in Bettas.

to the alternation

if the “reply” to be emitted

signal.

that “challenging”,

theoretical

displays

possibility

further

the fish sequentially

of subordinate

in information

(1955) who reported

would appear

of display function

1968); this is analogous

especially

of the incoming

preceding

threat

interaction

(Simpson,

behaviour

1982).

interpretation

in red deer, and would similarly

assessment

in the agonistic

from this and other studies

the proposed

course of an aggressive

to be involved

1978; Maynard-Smith,

fish. involved

in

(Peeke & Peeke,

Hoyenga,

fight outcome

at a slow rate should dominate

and Ward in Bettas; fish whose

119

aggressive pointed

responding

habitutes

rapidly”.

out that while habituation

However,

Rhoad, Kalat and Klopfer

is usually defined

in a purely descriptive

(1975) have

manner,

often used as if it were an explanation,

and the Peeke and Peeke hypothesis

fore be “completely

when Meliska and Meliska (1976) compared

fight performance their future opponents

Further,

of pairmembers

opponent

display via visual stimulation

subordinate pre-fight

than an unhabituated

experiences.

with which they were later paired, of this latter isolated.

After

of the nine isolate

fewer between

threat

that there

display and attack commence

biting soon after

(Braddock

& Braddock

mirror group and both members to their opponents

before

be assessed

experience,

by Bettas

ant/subordinate

a third.

sessions”, the isolate

being placed

fish

of dissociation” newly paired Bettas

together,

but rather

display for

1968); since one member

viewing group had observed

together,

only two

they bit less and formed

However,

1955; Simpson,

of the

and displayed

the higher levels of biting and jawlock-

with an information

transfer

from its display behaviour

relationships

in pairs; the mutually

and the isolates

be a “degree

in these groups should not have been unexpected.

are also compatible

or the images

while a fourth group were

note that although

in Bettas.

of the mutually

being placed

Meliska,

fish and six out of seven mirror pairs

may therefore

behaviours

that

to the conspecific

in ten 15 minute “combat

as the fish with pre-fight

they suggest

some time initially

ing observed

viewing

fish pairs did so. The authors

as vigourously

jawlocks;

do not typically

results

either

the fish were placed together

relationships

of their

from pairs of Bettas

side of a one way mirror,

one group, the two mirror groups a second,

While five out of six pairs of mutually

displayed

More recently, obtained

The fish were exposed

124 hours of exposure

dominant/subordinate

image or that of

would make a fish more likely to

animal”.

the fight lengths

the reflecting

the

they found no evidence

group viewed from the other side of the mirror

viewing fish formed formed

to their own mirror

be disadvantaged)

Meliska and Peeke (1980) have compared with different

either

may there-

being that fish with visual experience

and therefore

of aggressive

socially

exposed

(the expectation

would habituate

“habituation become

circular”.

it is

view.

Interestingly,

these

If an opponent’s

then the rapid resolution

RHP can

of domin-

in the two groups with 124 hours of mutual or one-member

viewing would be predicted. In summary,

the aggressive

display of Bettas

tion about RHP, and since this is, in some cases, explanation

of the data, accounts

that habituation

is of primary

of agonistic

importance

seems to contain

an alternative

accurate

informa-

(and more parsimonious)

behaviour

in this species

in determining

fight outcome

which suggest may need to be

re-examined. ACKNOWLEDGEMENTS The author for providing ment.

Pilot studies

the materials

would like to thank the Zoology Department

space and facilities, were conducted

of Cambridge

University

and Dr. M. J. A. Simpson for his help and encouragewith S. C. Savill who helped design the apparatus,

for which were provided

by J. J. Clark.

Dr. S. J. Gaioni, J. C. Hanson and

120

an anonymous

referee

all made suggestions

which improved

earlier

versions

of the manu-

script.

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Peeke,