Effect of social isolation on aggressive behaviour of fish

Bc. Dominika Hondlíková

Master's thesis

Abstract:

The effects of social isolation on the agonistic encounters of males of Betta splendens were investigated. The literature review of this thesis focused mainly on the mechanisms of aggressive behaviour modulation by various levels of isolation from social networks. Also the effects of exposition to different sexes in social environment prior to agonistic encounters with conspecifics were summarized. Methods from the stated researches were considered in this thesis experiment design.58 male individuals of were housed individually in transparent boxes. They were divided into three groups according to the level of social isolation: socialized with male individuals (M socialized males), socialized with female individuals (F socialized males and fully isolated males (Isolates). The experiment took place two times with different durations to compare the effects of long termed (6 weeks) and short termed (3 weeks) isolation. Video recording of every subjects reaction to mirror was carried out after both experiments. Despite having hypothesised, that isolation will result in increased aggressiveness, no significant (p>0.05) effect of treatment was noted after evaluating duration of two aggressive behaviours; opercular flaring and biting. Also there was no effect of isolation on the display readiness and the difference of latency to display between treatments was not significant (p>0.05) in isolates. Results were not in accordance with Lorenzs (1950) hypothesis that males elevate their aggressive reaction to their opponents after a period of social isolation, and results are discussed.

Keywords

aggressiveness, Betta Splendens, social interaction, Siamese fighting fish

Jazyk práce: English

Datum vytvoření / odevzdání či podání práce: 27. 4. 2017

Obhajoba závěrečné práce

• Vedúci: Ing. Tamara Fedorova, Ph.D.
• Oponent: Vladimír Vrabec, Ph.D.

Czech University of Life Sciences Prague

Faculty of Tropical AgriSciences

Master programme / odbor:
Tropical Agriculture / Wildlife Management in the Tropics and Subtropics