Agonistic and reproductive interactions in Betta splendens.

Area of Science:

• Ethology
• Animal Behavior
• Fish Biology

Background:

• Siamese fighting fish (Betta splendens) exhibit complex social interactions, including agonistic and reproductive behaviors.
• Understanding the determinants of dominance and reproductive success is crucial for managing this popular aquarium species.

Purpose of the Study:

• To investigate the factors influencing reproductive and agonistic behaviors in Siamese fighting fish.
• To isolate consequences and determinants of social interactions, including dominance hierarchies and reproductive success.

Main Methods:

• Eight experiments were conducted to analyze fights and dominance-subordinancy relations.
• Factors such as body size, prior residency, tank cue familiarity, and chemical cues were manipulated and observed.
• Behavioral observations included displays, nest building, space access, and approach to females and mirrors.

Main Results:

• Larger body size and longer prior residency in a tank conferred an agonistic advantage.
• Prior residency effects were linked to familiarity with visual and tactile tank cues.
• Dominant males showed increased access to space, mirror displays, nest building, and female approach.

Conclusions:

• Body size, prior residency, and environmental familiarity are key determinants of dominance in Betta splendens.
• Chemical cues from tank dividers significantly influence social behavior, highlighting the role of olfactory and chemical sensing.
• These findings provide insights into the complex interplay of factors governing social and reproductive strategies in Siamese fighting fish.