Male Betta Research Articles

Effect of telencephalon ablation on the reinforcing and eliciting properties of species-specific events in Betta splendens.

In male Betta splendens, aggressive behavior is drastically attenuated following telencephalon ablation. Because instrumental training and Pavlovian conditioning experiments with intact fish have suggested that associative factors may play an important role in the performance of agonistic behaviors, the effect of ablation on instrumental learning and Pavlovian conditioning was studied. In Experiment 1, ablation had no effect on the learning of the instrumental tunnel-swimming response reinforced by mirror presentation (i.e., viewing a conspecific), although the mirror presentations in yoked-control groups elicited fewer responses in ablates than in normal and sham-operated control fish. Yoked controls further established that instrumental responding was maintained by the reinforcement contingency and was not merely the result of increased motor activity. Experiment 2 studied Pavlovian conditioning of the components of the agonistic display. Unconditioned fin erection, gill erection, and tail beating (i.e., unconditioned responses, URs) to the mirror US all were less frequent in ablates than in normals or shams. Of these, only gill cover erection showed evidence of true conditioning (i.e., conditioned responses; CRs) in which responses to the conditioned stimulus (CS) are due to the pairings of CS and US (unconditioned stimulus). However, ablates suffered no impairment of conditioned gill erections. Ablates performed fewer fin erections to the CS; however, fin erection responses were not due to CS-US pairings but were attributable to pseudoconditioning. These results are related to hypotheses postulating the involvement of learning mechanisms in ablation-produced deficits and normal aggressive behavior.

Commitments to aggression and nest sites in male Betta splendens.

Male Siamese fighting fish construct nests that are relatively isolated from conspecific males. Following nest construction, the presence of a male opponent elicits (a) nest fixation, (b) further nest building, and (c) Betta's agonistic sequence, i.e., attacks alternating with flight movements, along with gill displays occurring near the opponent. The form of a male-male encounter depends upon the distance between a resident's nest and the opponent as well as upon the individual differences in combatants' tolerance for the presence of a conspecific nearby. Also, the intensity of aggression early in an encounter is positively correlated with the intensity of subsequent fighting. Male Bettas appear to compete for space through the use of aggressive behavior and to coordinate their fighting activities by means of visual signals. An incentive model of visual communication is proposed in which visual cues emanating from a displaying male opponent elicit attack with an intensity that is directly proportional to the persistence of the opponent and inversely proportional to the distance between fish.

Betta splendens: A territorial note

Two communities of Siamese fighting fish were observed, each for about 4 months. Males occasionally built nests, and these structures were always located in corners. Consistent with Goldstein’s (1975) report, male Bettas chose isolated areas for nest building and spawning.

The relationship of mirror-elicited display to combat behaviors in Betta splendens

Thirty-eight male Betta splendens were screened to identify individuals exhibiting either high or low levels of reactivity to a mirror. Fish which displayed at the mirror for short durations were matched for combat with either (a) other short-duration displayers (the Short—Short group; N = six pairs), or (b) long-duration displayers (the Long—Short group; N = seven pairs). In combat, Short—Short pairs fought less intensely than Long—Short pairs; but within Long—Short pairs, short- and long-duration displayers did not differ in combat vigor. Correlations between combat behaviors and precombat mirror display measures tended to be positive, but were mostly small and nonsignificant. Correlations with postcombat mirror displays were greater. Results imply that mirror-elicited threat behaviors provide a partial predictor of actual combat aggression in Betta .

Belontiidae chemosignal activity: interspecific attraction and perceived chemosignal similarity

Belontiidae chemical communicatory substances were examined for interspecific behavioral activity. In Experiment 1, male Betta were exposed to ripe-female-conditioned water (RFCW) from either the goldfish (Carassius auratus) or one of the following Belontiidae species: (a) Betta splendens, (b) Colisa labiosa, (c) Colisa lalia, (d) Macropodus opercularis, or (e) Trichogaster trichopterus. Time spent near and within a stimulus source tube was used to measure the chemosignal activity for each species. Both behavioral measures showed evidence for interspecific chemocommunication. The proximity measure indicated a phylogenetically nonspecific chemosignal, whereas tube occupancy indicated the presence of a specific Belontiidae system. Experiment 2 was a stimulus generalization test using a psychophysical paradigm. Male Betta were trained to discriminate Betta RFCW from Carassius RFCW, and were subsequently presented with RFCW from either (a) C. lalia, (b) M. opercularis, (c) T. trichopterus, and (d) P. reticulata. The latter were novel stimulus generalization chemosignals. The male Betta perceived Belontiidae RFCW stimuli as similar, whereas guppy RFCW was neither perceived as Belontiidae nor Carassius RFCW. Thus, Belontiidae chemosignals may be similar in structure due to a common phylogenetic ancestry.

Threat displays and combat aggression in Betta splendens following visual exposure to conspecifics and one-way mirrors

Sixteen pairs of adult male Betta splendens were tested for waning of threat displays during 124 hr of exposure to either conspecifics or to one-way mirrors. In the one-way mirror condition, eight fish viewed their own mirror images while their respective pair members viewed them through the transparent, nonreflective sides of the one-way mirrors. Mirror viewers displayed much more persistently than fish which viewed them through the one-way mirrors, and somewhat more than conspecifics which viewed each other through clear partitions. When the visually preexposed pairs were later permitted to fight, viewing mirrors or other conspecifics prior to combat had not reduced attack readiness. In fact, visually isolated control pairs fought less than visually preexposed fish; subsequent visual exposure to opponents reversed the effects of visual isolation. Results suggest that threat displays in restrained Betta wane when fish withhold threat-sustaining visual feedback from each other. And while threat displays may be reduced by viewing mirrors or conspecifics, actual attack readiness is not, suggesting that threat and attack components of aggression may vary independently of each other.

Maintained aggressive behavior in gonadectomized male siamese fighting fish ( Betta splendens)

Adult male Betta splendens were gonadectomized and tested twice for aggressive behavior two weeks later. In a mutual viewing test environment, it was found that gonadectomized animals maintained their aggressive behavior on all six indices of aggression at a level equal to controls. Animals that showed some testis regeneration and sham operated fish were also equal to controls. The results are interpreted to mean that adult aggressive behavior in male B. splendens may not be under the control of gonadal hormones. Pituitary gonadotropins, interrenal gland, and critical period hypotheses are given as possible explanations of the maintained aggressiveness following castration.

Spatial discrimination of display and partial-display contingencies by male siamese fighting fish

Three male Betta splendens preferred to perform an operant which permitted them to display freely to a mirror for 30 sec over an operant in which the initiation of display movements resulted in mirror termination. One fish, which showed the opposite preference, received more time with his mirror image as a consequence. These results are consistent with a theoretical view which holds that a history of reinforcement provided by consummatory responding is sufficient for an instrumental activity to occur.

Social chemosignals in five Belontiidae (Pisces) species.

Approach behaviors toward conspecific chemical stimuli of the opposite sex were examined in five Belontiidae species: Betta splendens, Macropodus opercularis, Colisa labiosa, C. lalia, and Trichogaster trichopterus. Approach was measured by (a) preference for section 1 of a three-section tank, which contained a vertical tube that introduced the stimulus water, and (b) occupancy of the tube. Experiments 1A and 1B showed that (a) approach behaviors were displayed by the isolated male Betta only to ripe-female stimulus water, (b) group-housed males of the remaining four species were not attracted to female-conditioned water, and (c) socially isolated males of these four species preferred section 1 during presentation of either ripe- or nonripe-female-inhabited water but occupied the tube only during exposure to ripe-female-conditioned water. The findings of Experiment 2A were that (a) the female Betta, regarless of physiological state, showed approach behaviors to male-inhabited water and (b) only ripe females of the remaining species indicated a preference for section 1 during male-water exposure but performed no tube entries. Results of Experiment 2B indicated that social isolation of the females, especially ripe females, facilitated their approach behaviors.

Modification of Consummatory (Attack) Behavior Resulting From Prior Habituation of Appetitive (Threat) Components of the Agonistic Sequence in Male Betta Splendens (Pisces, Belontiidae)

To investigate the effects of habituation of threat behavior on subsequent attack in pairs of conspecific male Siamese fighting fish (Betta splendens), two experiments were performed. In Experiment I, pairs of fish were separated by either a clear or opaque Plexiglas partition for 6 hours. The partition was then removed and the pairs met in a I hour direct encounter. The pairs which had been in visual contact for the 6 hours during which threat display occurred showed less fighting than the visually isolated pairs. However, in the group having visual contact much biting was directed at the partition during the 6 hour habituation period, a possible explanation for decreased fighting during the direct encounter. Therefore, Experiment 2 was conducted in such a manner that the biting at the partition was eliminated (although threat responses were retained) by separating the pairs by 5.08 cm for the 6 hour habituation period. A second group was separated by 12.60 cm to investigate response-independent effects of habituation since no threat responses were elicited at that distance. A third group was separated by an opaque partition as in Experiment I. The subsequent direct encounters were 60 minutes as in Experiment I. The only quantitative difference in attack behavior between groups was in the first 5 minutes, where the pairs separated by 12.60 cm bit less than pairs in the other two groups. This attack difference is explained in terms of an initially retarded agonistic sequence as compared to the other groups, apparently resulting from a combination of habituation and response-independent treatment effects. However, once fighting began in the habituation groups, it was qualitatively more vigorous than in the nonhabituation group. Also, in several instances, there was an unexpected appearance of intermale quasi-sexual behavior in the habituation groups only. The present experimental paradigm is interpreted as being that of a dominance encounter rather than either a territorial boundary fight or a territorial defense against an intruder. It is suggested that threat habituation does not attenuate subsequent attack in a dominance situation, but it is possible that there may be such an attack attenuation if the same operations were applied to clearly territorial Siamese fighting fish.

Aggression and avoidance byBetta splendens toward natural and artificial stimuli

The aggressive display of male Bettas was elicited maximally by another male, followed by a mirror image, a moving model, and a stationary model. The same order of effectiveness obtained regardless of the order of presentation of the stimuli. After a few days’ exposure to each stimulus, 1 h per day, the Bettas’ aggressive displays declined sharply. This did not represent a loss of attentiveness to the stimulus, but an active avoidance response. It is argued that this and other behaviors classified as “habituation” may profit from further behavioral analysis.

Sexual Discrimination in the Siamese Fighting Fish (Betta Splendens Regan)

Abstract I. We recorded the responses of male Betta splendens when presented with various stimuli behind a transparent partition. The stimuli comprised i) live male and female B. splendens; ii) lifelike (motionless) models of male and female B. splendens; and iii) six stylised model B. splendens. The stylised models consisted of three pairs, one member of which had long male-like fins and raised opercula, and the other with short female-like fins and lowered opercula. The first pair had "aggressive", the second, "submissive", and the third, "reproductive" colouration. 2. The use of two techniques for comparing responses to the different stimuli was compared. Principal component analysis of unscaled data produced more satisfactory results than did clustering by single linkage on the basis of taxonomic distances calculated on scaled data. 3. The response by a male to a stimulus consisted of two categories of behaviour: "agonistic" display and nest-oriented activities. 4. The responses towards live males and females differed only in the relative amounts of "agonistic" and nest-oriented behaviour performed to each. A greater amount of "agonistic" behaviour was performed towards males. 5. Three main influences were found affecting a male's response to a conspecific: i) a tendency to perform all components of "agonistic" display and to inhibit performance of nest-oriented behaviour; ii) and iii) tendencies to perform particular components of the "agonistic" display. Thus the "agonistic" display was found to be complex and governed by at least three separate motivations. 6. The first influence varied according to the (perceived) sex of the stimulus, being great when the stimulus was a male, and slight when it was a female. The other two influences were independent of the nature of the stimulus. 7. Responses to lifelike, motionless models were very similar to those to live fish. 8. All male models and the "aggressive" female model were treated similarly to the live male. The other models were treated similarly to the live female. 9. A mechanism for sexual discrimination was proposed, in which a male is characterised by long fins and/or raised opercula, or, an unpatterned body. A female is characterised by short fins and a patterned body. Discrimination can be accomplished solely by use of visual stimuli.

On the choice between eating and aggressive display in the Siamese fighting fish ( Betta splendens)

In Expt 1, male Betta splendens were given a choice between food and a mirror image in a T-maze. All fish consistently preferred food. In Expt 2, the choice of fish that lived in the T-maze for the duration of the experiment was compared with the choice of fish that were transferred to the T-maze for each experimental session. Fish that lived in the T-maze consistently preferred food, but fish that were transferred showed a shift in preference toward mirror image. Differential inhibition of hunger and aggression by fear is suggested as the cause of the preference shift.

The Relation Between Eliciting Stimulus Strength and Habituation of the Threat Display in Male Siamese Fighting Fish, Betta Splendens

AbstractThe threat display of the male Siamese fighting fish (Betta spiendens) is a highly integrated phenomenon, involving approach, extension of the gill covers (opcrculae) and brachiostegal membranes, erection of the medial fins, intense deepening of body color, orientation movcmcnts, and undulatory movements. Many qualitatively different stimuli are capable of eliciting the complete threat display (e.g., live male Betta, mirror image, two dimensional cut-out). However, the relations between the initial eliciting strength of the threat stimulus and the degree of habituation, retention, and recovery of habituation have not been systematically investigated. These relations are important in an eliciting stimulus and competing response theory of habituation like that of RATNER (1970). To investigate the above relations, 40 adult male Bettas were randomly assigned to four independent groups (n = 10). Each S in a particular group was exposed to one of four different eliciting stimuli for two 40 minute sessions separated by a 24 hour rest period. The four thrcat elicitors were: a live unhabituated, highly responsive male Bettca (Unhab. male); a mirror image (Mirror) ; a livc habituatcd, relatively unrcsponsive male Betta (Hab. male) ; and a two dimensional cut-out of a male Betta in lateral display (Cut-out). During threc ro minute observation periods in each session, five different reliable components of the display were simultaneously recorded: air gulping frequency (AG), gill cover erection frequency (GF), gill cover erection duration (GD), fin erection frequency (FF), and fin erection duration (FD). For all five dependent measures, the Unhab. male stimulus was the strongest elicitor followed by the Mirror, Hab. male and Cut-out stimuli, respectively. Only two of the dependent measures (GD, FD) showed a systematic decrement for all stimulus groups. With respect to both of these measures, initial eliciting stimulus strength (response level during the first 10 minute observation) was positively related to absolute response decrement, and proportion of recovery of habituation. Initial eliciting stimulus strength was inversely related to the proportion of decrement across sessions, and the proporton of retention of habituation over a 24 hour period. Four of the threat components (GF, GD, FF, FD) were highly positively related. AG was shown not to be an integral component of the display, itself. The data provided support for portions of an eliciting stimulus and competing response theory of habituation.

Catechol amines and social relations in siamese fighting fish

Mirror-elicited aggressive displaying was observed in isolated male Betta splendens. Epinephrine and norepinephrine both suppressed aggressive displaying, compared with controls in sodium chloride solution or plain water. Subsequent group dominance encounters indicated that fish which displayed most in water, sodium chloride solution, or in catechol amines were dominant in groups of five fish. This was not true in dominance hierarchies based on paired, round-robin encounters. The third experiment showed that dominance-submission relations between pairs of fish were highly stable; epinephrine had the effect of making some dominant subjects appear and behave like all submissive fish in that they paled and did not display to live submissive opponents. Such dominant fish were however still able to assert their dominance by consistently chasing their opponents.

Operant and classically-conditioned aggressive behavior in Siamese fighting fish.

Male Betta splendens were conditioned to emit an operant response sequence reinforced by presentation of a model of another male Betta in aggressive display (Thompson, 1963). The color of the model with respect to the color of the subject co-varied with the rate of operant response (Thompson and Sturm, 1965). In another experiment, unconditioned aggressive display behavior elicited by the mirror image of a male Betta was brought under the control of a previously ineffective stimulus by classical conditioning. Relative rates of acquisition of four components of the display were compared. A discriminative conditioning procedure, using two different colors of light as the CS, revealed that the response was elicited specifically by the CS (Thompson and Sturm, 1966).

Classical conditioning and punishment of an instinctive response in Betta splendens

Normal Betta splendens males extend their gill membranes to the visual stimulus of their mirror image or another male. This response was classically conditioned to a weak electric shock. Gill membrane extension to an opponent was suppressed by punishing it with a strong electric shock. These experiments demonstrate that an arbitrary stimulus can come to release certain instinctive patterns of response in the male Betta through the method of classical conditioning, and that punishment of this behaviour can suppress its occurrence to a normal stimulus. In this example, both methods could be used to control the same response.