A Comparison of Male Betta Fish (Betta splendens) Aggression With and Without an Audience

Taylor Holguin and Andrew Najem

Introduction:

Aggression may be provoked when an animal: encounters a member of its own species and sex, is in close proximity with a rival, is approached by another aggressive individual, and above all encounters a stranger (Marler, 1976). (start with this, more interesting)The proposed project will study the aggressive behaviors of male Betta fish (Betta splendens)when exposed to a foreign male with and without an audience present, whether it iseither a male or a female. Many animals display of male-male interaction are altered when an audience is introduced (Dzieweczynski and Perazio, 2012) due to the individual desire to be titled as alpha male. It has been foundtested that the image of an opposing male betta fish is a reliable source of aggressive display in male betta fish (Wirth et al., 2008). Male-male Betta interactions when in the presence of a female audience typically consist of tail beats toward the opponent (Animal Behavior, 2012). It is predictedour hypothesis states that with the presence of a female audience, male aggressive behaviors will increase.

Methods and Measurements:

The study took place at the Najem residence in Mission Viejo, California. Ten male Betta fish and three female Betta fishwere purchased between Petco, Petsmart and Kahoot’s pet stores located in Mission Viejo, CAto obtain a variety of color and size in the fish. A 5.5-gallon tank and fish food were purchased at Kahoot’s, and a sheet of 45.75 cm x 61 cm plexi-glass was purchased at Denault’s Hardware Store, also located in Mission Viejo, Ca. The fish were housed individually and fed two pellets of food two times a day. The sheet of plexi-glass was cut into dividers that split the tank into a T-formation. Two of the compartments of the T-formation were roughly 10.15 cm x 28 cm and were designated for the use of testing the male Betta fish. Above this section at the top of the T-formation was the audience compartment, which measured in at 20.30 cm x 10.15 cm. Between the male Betta fish and the audience compartments was a small gap that measured approximately 20.30 cm x 2.54 cm.

Maybe put an image of a camera, just like you did for the PowerPoint presentation

The initial experiment occurred between two male Betta fish without an audience present. The tank was partitioned with a board between the two compartments that the test subjects would be placed in to restrict any view of each other. The two male Betta fish were placed in the test tank in their proper compartmentsand were given 15 minutes to adjust to their new environment before being able to see each other. After the fish had time to adjust, the board between them was removed and the fish were recorded with a GoPro camerafor a 10-minute period to observe their behavior. Analysis took place afterwards where aggression duration was recorded andgill flares and tail kicks were counted. This part of the experiment repeated four more times until all ten male Betta fish had been tested.

The second part of the experiment occurred between two male Betta fish in the presence of a female audience. This occurred in the exact manner, as before, with a board between themale Betta fish that were unfamiliar with each other. The compartment with the female audience was not partitioned off so both individual males could see the female audience during both the acclimation period, where the males could not see each other, and the testing period. After the 15-minute acclimation period, the partition was removed between the male test subjects and the timer was started for 10 minutes. Again, the GoPro camera was used to record both fish for the allotted time. These tests were continued until all males had been tested and recorded. Videos were analyzed for duration of aggression, as well as number of tail beats and gill flares.

The final part of the experiment occurred in the same manormanner as before, exceptthis timeanother male was brought into the unblocked audience compartment and was allowed to familiarize itself with the individual, separated test males. After 15 minutes, the board in between the two male test subjects was removed and the GoPro was used to record 10 minutes of activity between the two males. All ten males were tested in this fashion and videos were analyzed afterward for duration of aggression as well as the number of tail beats and gill flares.

Results:

INDENT After analyzing the data, it was foundthat the average number of gill flares recorded was significantly higher in the tests with a female audience compared to a male-audience. Gill flares average 36.7 ± 2.6 (±SEM, n=10, Figure 1) for the male-male interactions with a female present. For the male-male interactions with a male audience present, the gill flares average 21.2 ± 3.2 (±SEM, n=10, Figure 1). The control test, male-male interactions with no audience, yielded a gill flare average of 31.8 ± 5.5 (±SEM, n=10, Figure 1) and there was no significant difference between the absence of an audience and female or male audiences present.

In regards to the mean quantity of tail beats, it appears that there was a significant decrease in tail beats of the male-male interactions with a male present in comparison to the tests done without an audience present. The mean tail beats of the control, male-male interactions with no audience is 16.4 ± 3.2 (±SEM, n=10, Figure 2). For the interactions with a female audience present, the average tail beats are 12.4 ± 1.2 (±SEM, n=10, Figure 2) and the male-audience tests resulted in an average of 5.1 ± 1.26 (±SEM, n=10, Figure 2) tail beats.

Lastly, the time of aggression, measured in seconds, did not see a significant difference in any of the categories. The results were very widespread for each of the tests and yielded fairly high measurements of standard error for these tests. The control, no-audience tests show an average time of 259.7 ± 41.3 sec (±SEM, n=10, Figure 3). Female-audience tests resulted in a mean of 225.1 ± 10.8 sec (±SEM, n=10, Figure 3). The male-audience yielded a mean duration of aggression of 182.5 ± 28.5 sec (±SEM, n=10, Figure 3).

Figure 1:The graph represents the mean quantity of gill flares by individual male Betta fish in the presence of the specified audience. Female-audience gill flares were significantly greater than Male-audience gill flares (p=0.00845, ANOVA with Bonferroni Correction). Error bars represent mean ± SEM.

Figure 2: The graph represents the mean quantity of tail beats displayed by male Betta fish in the presence of the specified audience. The mean number of tail beats were significantly greater with no-audience in comparison to Male-audience tail beats (p<0.0165, ANOVA with Bonferroni Correction). Error bars represent mean ± SEM.

Figure 3:The graph represents the mean duration of aggression (sec) displayed by male Betta fish in the presence of the specified audience. According to the ANOVA analysis with Bonferroni Correction, there was no significant difference in any of the measured durations.

Discussion:

Animals are typically very aggressive toward any outside threat that challenges their hierarchy (Dzieweczynski and Perazio, 2012). This test touched on covered all aspects of this claim plus expanded to include the presence an audience member (male or female). A male Betta fish was paired with another male Betta fish and these individuals were only separated by a few millimeters of plexi-glass. Both males were usually aggressive toward one another, and both were unfamiliar with the other male. The audience Betta fish was farther away to restrict the interaction and was intended to be a visual stimulus for the two males being tested.

It was predicted thatwe tested our hypothesis in which there would be an increase in aggressive behaviors between the male Betta fish in the presence of a female audience. These behaviors include an increase in duration of aggression (sec), number of gill flares, and number of tail beats. The basis of this natural response in the fish comes from the fight-or-flight response. This instinct is triggered when the central nervous system sends signals to the central command neurons that control the heart and the adrenal glands (Jansen et al., 1995). According to the tests, the only significant increase for the presence of a female-audience was in the mean quantity of gill flares, and this was only significant over the mean quantity of male-audience gill flares. In comparison to the control test of no-audience present, there was not a significant increase. The display of the males with the female audience present was much more intense than the other tests despite the shorter durations of aggression. Some species of fish, such as the Zebrafish (Danio rerio) have been found to have females that prefer males with larger body sizes (Pyron, 2003). Female Betta fish may have the same preference in males, which would lead to the increase in gill flares. The flaring of a male’s gills along with spreading its fins, as much as possible, would maximize its size.

In the data regarding tail beats, it was found that there was a significant decrease in the amount of tail beats displayed in the male-audience tests compared to the no-audience control tests. This suggests that in the presence of all males it is unnecessary to display bright, colorful fins. Overall, the aggressive displays of the males decreased in all three measurements when in the presence of another male as the third party. This could have been due to an individual’s fear of being outnumbered two-to-one. In one study regarding Black howler monkeys (Alouatta pigra), it was supported that alpha male monkeys showed the lowest levels of retaliation when faced with unfavorable odds. This situation was simulated when the alpha male listened to auditory recordings of several male group members (Kitchen, 2004). A similar effect could have happened to the test males when an individual experienced two outside males displaying aggression directed toward the one individual. As the tests supported, male-male interactions were low in all aspects, being significantly less in the category of tail beats.

Duration of Aggression was found to have no significant difference between all three categories. In conclusion, the hypothesis that aggressive displays of male-male Betta fish interactions would increase in the presence of an audience female was only supported in one of the three criteria. Due to these unfavorable results, the hypothesis can be reasonably rejected. The null hypothesis that male-male aggressive displays will not be significantly greater when in the presence of a female audience is supported, and therefore accepted.

References:

Animal Behavior; Researchers from University of New England Publish New Studies

and Findings in the Area of Animal Behavior. 2012.

Dzieweczynski, Teresa L. and Christina E. Perazio. 2012. I Know You: Familiarity with

an Audience Influences Male-Male Interactions in Siamese Fighting Fish, Betta

Splendens.Behavioral Ecology and Sociobiology66 (9): 1277-1284.

Jansen, Arthur S. P., Xay Van Nguyen, Vladimir Karpitskiy, Thomas C. Mettenleiter, and

Arthur D. Loewy. 1995. Central Command Neurons of the Sympathetic Nervous

System: Basis of the Fight-Or-Flight Response.Science270 (5236): 644.

Kitchen, Dawn M. 2004.Alpha Male Black Howler Monkey Responses to Loud Calls:

Effect of Numeric Odds, Male Companion Behaviour and Reproductive

Investment. Animal Behavior. 125-139.

Marler, Peter. 1976. On Animal Aggression: The Roles of Strangeness and

Familiarity. American Psychologist31 (3): 239-246.

Pyron, M. 2003. Female Preferences and Male-Male Interactions in Zebrafish (Danio

Rerio).Canadian Journal of Zoology81 (1): 122-125.

Wirth, Oliver, Kennon A. Lattal, and Sandra Hopko. 2003. Using Visual Reinforcement

to Establish Stimulus Control of Responding of Siamese Fighting Fish (Betta

Splendens).Journal of Comparative Psychology117 (1): 111-118.

Review Form

Department of Biological Sciences

SaddlebackCollege, Mission Viejo, CA92692

Author (s): Taylor Holguin and Andrew Najem

Title: A Comparison of Male Betta Fish (Betta splendens) Aggression With and Without an Audience

Summary

Summarize the paper succinctly and dispassionately. Do not criticize here, just show that you understood the paper.

  • Beta fish are an aggressive type of fish, and to test that they used other fish as an audience to see their behavior when being watched. Their hypothesis is that when there is an audience watching, their aggression will increase. They tested this by using a tank that had three compartments and a camera. After letting the single fish swim around for some time, they introduced another fish (male) to see its behavior; specifically the gill flares and tail beats which both represent aggression. Then they did the same thing but with the presence of a female fish. After these testing, they counted the number of aggression behavior that each fish demonstrated and by that conducted statistics to see if there was an increase or not. The testing and statistics did not support their hypotheses; therefore they accepted their null hypothesis.

General Comments

Generally explain the paper’s strengths and weaknesses and whether they are serious, or important to our current state of knowledge.

  • Great knowledge on the subject, good use of references.
  • The biggest strength is the attention to detail that they explained in their methods and measurements and results. Every word that was used fit into the paragraph and made sense to imagine what was happening during the research.
  • The weakness of this is the introduction only because it did not interest me from reading the first 2 sentences. Should start the introduction with the sentence “Aggression may be provoked when an animal: encounters a member of its own species and sex, is in close proximity with a rival, is approached by another aggressive individual, and above all encounters a stranger (Marler, 1976).” Then after that sentence follow with information about Beta fish, just like it was done during the presentation. Organize the rest of paragraph according to this main statement.

Technical Criticism

Review technical issues, organization and clarity. Provide a table of typographical errors, grammatical errors, and minor textual problems. It's not the reviewer's job to copy Edit the paper, mark the manuscript.

  • Capitalizing Beta Fish
  • Organization of introduction needs to be rearranged
  • Indenting when starting a new paragraph

This paper was a final versionThis paper was a rough draft

Recommendation

 This paper should be published as is

This paper should be published with revision

 This paper should not be published

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