Betta Lab Report (soose)

How movement of mirror affects the agonistic behavior of a Siamese Fighting Fish.

Ashley Soucy 09-10-2008

Introduction: Ethology is the study of animal behavior in the context of ecology, evolution, social organization, and the sensory abilities of an animal. When observing and analyzing animal behavior you look for the to basic categories of behavior, learned and innate behaviors. Siamese Fighting Fish, more commonly known as Betta Fish, are very territorial and aggressive towards each other, an agonistic but also innate behavior. When Betta fish feel threaten, they will flare up, increase fin speed, and lunge towards threatening Betta. In this lab we observed the the Betta's behavior as it was being provoked due to proximate and ultimate causes. Proximate causes being set stimulus and Ultimate being innate behaviors. We conducted an experiment by placing a mirror to the Betta, creating a safe stimulus of another Betta fish. In doing this experiment we will observe if the Betta fish becomes more aggressive if we station the mirror in one spot or if we constantly move the mirror, following his every move. Hypothesis: If the mirror is at constant motion with the Betta fish then then the Betta will have a quicker latency and slower recovery. Materials: ● ● ● ●

Betta Fish Fish Tank Stopwatch A Mirror

Procedure: 1. After forming a hypothesis, we began planning our experiment. We came up with three stimuli to test the Betta's aggressiveness. 1.) Leaving the mirror

stationary, 2.) Moving the mirror back and forth 180 degrees around the fish tank, 3.) Keep the mirror in constant motion. We kept the mirror stationary or in motion for a full one minute of each stimuli test. The independent variable is the latency and recovery of the Betta fish and the dependent variable is the duration of which we left the mirror present. 2. We placed the mirror in front of the Betta fish, and left it in that spot for exactly one minute. We observed that it took the full minute for the Betta to get in his aggressive state. The Betta's gills expanded and his fin speed increased. He would approach the mirror and then seemingly get bored and swim in opposite direction. After the one minute, we removed the mirror and it took him 30 seconds to calm down. 3. We then placed the mirror in front of the fish and moved it 180 degrees around the tank. We repeatedly moved the mirror back and forth around the fish tank for one minute. The Betta fish had not shown any reaction throughout this time period of the experiment. 4. For the last stimulus test we placed the mirror in front of the fish and constantly moving it counter clockwise around the tank. After forty seconds the Betta fish's fin speed increased, his kills widely expanded, and his colors brightened. After the one minute we removed the mirror and it took the Betta took twenty seconds for his appearance to become calm. Although after this stimulus test, unlike the others, he remained at the bottom of the tank, retracing his path of where he last saw the Betta, almost as though he was still looking out for the threat. Results/Data Collection:

Stationary mirror

Latency (seconds)

Recovery (seconds)

60

30

Moving 180 degrees back No Reaction and forth

No Reaction

Constantly moving 40 20 Table 1.1 Data of the Betta fish's Latency and Recovery time. (See Graph 1.2 on attached page.) Discussion/Conclusion: The result partially supported our original hypothesis, If the mirror is at constant motion with the Betta fish then then the Betta will have a quicker latency. When the mirror was in constant motion the latency of the Betta was faster than the stationary mirror. However the recovery was also much quicker when the mirror was removed after being in constant motion. From this data we concluded that naturally the fish feels more threatened when the mirror is in constant motion following him around the fish tank. Factors that may have alter the accuracy of our experiment is the distortion of the reflection due to the fish bowl. We cannot be sure that if the size of the Betta is also a variable to the stimulus.