Abstract
Social behavior can influence physiological systems dramatically yet the sensory cues responsible are not well understood. Behavior of male African cichlid fish, Astatotilapia burtoni, in their natural habitat suggests that visual cues from conspecifics contribute significantly to regulation of social behavior. Using a novel paradigm, we asked whether visual cues alone from a larger conspecific male could influence behavior, reproductive physiology and the physiological stress response of a smaller male. Here we show that just seeing a larger, threatening male through a clear barrier can suppress dominant behavior of a smaller male for up to 7 days. Smaller dominant males being “attacked” visually by larger dominant males through a clear barrier also showed physiological changes for up to 3 days, including up-regulation of reproductive- and stress-related gene expression levels and lowered plasma 11-ketotestesterone concentrations as compared to control animals. The smaller males modified their appearance to match that of non-dominant males when exposed to a larger male but they maintained a physiological phenotype similar to that of a dominant male. After 7 days, reproductive- and stress- related gene expression, circulating hormone levels, and gonad size in the smaller males showed no difference from the control group suggesting that the smaller male habituated to the visual intruder. However, the smaller male continued to display subordinate behaviors and assumed the appearance of a subordinate male for a full week despite his dominant male physiology. These data suggest that seeing a larger male alone can regulate the behavior of a smaller male but that ongoing reproductive inhibition depends on additional sensory cues. Perhaps, while experiencing visual social stressors, the smaller male uses an opportunistic strategy, acting like a subordinate male while maintaining the physiology of a dominant male.
Highlights
During social interactions, individuals receive multiple forms of sensory information and use these signals to establish and maintain dominance hierarchies [1,2,3]
After removing the opaque barrier from the experimental tank, the two dominant males appeared to be sharing the same shelter as intended by the design of the pot arrangement (Figure 1), After the opaque barrier was removed, the stimulus male and subject male started fighting for territorial ownership by displaying dominant behaviors through the clear barrier
This suggests that a visual stimulus of any intensity is sufficient to induce changes in behavior and physiology in the subjects that we describe below
Summary
Individuals receive multiple forms of sensory information and use these signals to establish and maintain dominance hierarchies [1,2,3]. Individuals change their physiological responses during social interactions. It is known that visual signals during social interactions can evoke changes in behavior patterns [5,6], circulating hormone concentration [7,8,9], monoaminergic activity [10,11], and neuropeptide gene expression [12]. Many fish species appear to rely on visual signals during social encounters to maintain their social hierarchy [2,7,13,14,15]. The importance of visual information in influencing social status, relative to other senses, is unclear
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
