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Social dominance modulates eavesdropping in zebrafish.

Abril-de-Abreu R, Cruz AS, Oliveira RF - R Soc Open Sci (2015)

Bottom Line: We found that only dominant bystanders who had seen the fight revealed a significant increase in directional focus (a measure of attention) towards the losers of the fights.Furthermore, our results indicate that information about the fighters' acquired status was collected from the signalling interaction itself and not from post-interaction status cues, which implies the existence of individual recognition in zebrafish.We suggest that this type of integration of public and private information may be ubiquitous in social learning processes.

View Article: PubMed Central - PubMed

Affiliation: Instituto Gulbenkian de Ciência , Rua da Quinta Grande 6, Oeiras 2780-156, Portugal ; ISPA-Instituto Universitário , Rua Jardim do Tabaco 34, Lisboa 1149-041, Portugal ; Champalimaud Neuroscience Programme , Avenida de Brasilia , Lisboa 1400-038, Portugal.

ABSTRACT
Group living animals may eavesdrop on signalling interactions between conspecifics and integrate it with their own past social experience in order to optimize the use of relevant information from others. However, little is known about this interplay between public (eavesdropped) and private social information. To investigate it, we first manipulated the dominance status of bystander zebrafish. Next, we either allowed or prevented bystanders from observing a fight. Finally, we assessed their behaviour towards the winners and losers of the interaction, using a custom-made video-tracking system and directional analysis. We found that only dominant bystanders who had seen the fight revealed a significant increase in directional focus (a measure of attention) towards the losers of the fights. Furthermore, our results indicate that information about the fighters' acquired status was collected from the signalling interaction itself and not from post-interaction status cues, which implies the existence of individual recognition in zebrafish. Thus, we show for the first time that zebrafish, a highly social model organism, eavesdrop on conspecific agonistic interactions and that this process is modulated by the eavesdroppers' dominance status. We suggest that this type of integration of public and private information may be ubiquitous in social learning processes.

No MeSH data available.


Related in: MedlinePlus

Social eavesdropping paradigm. (a) Three-dimensional diagram of the experimental set-up. Left wall coverings of the test and demo tanks are removed for easier visualization. (b) Timeline of experimental procedure. (c) Schematic of eavesdropping test (day 3), composed of three 30 min stages: pre-fight, fight-observed/fight-not-observed and post-fight. Demonstrator fish in white and focal fish in grey, belonging to four conditions: bystander dominant (BD), bystander subordinate (BS), control dominant (CD) and control subordinate (CS). At the post-fight stage, the side of winner (w) and loser (l) demonstrators is randomized. (d) Schematic of a focal fish's mean resultant directional vector, composed of the vector's length R and mean angle α(0° opposite and 180° directed towards the stimulus), and R projected onto 180° (Rproj).
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RSOS150220F1: Social eavesdropping paradigm. (a) Three-dimensional diagram of the experimental set-up. Left wall coverings of the test and demo tanks are removed for easier visualization. (b) Timeline of experimental procedure. (c) Schematic of eavesdropping test (day 3), composed of three 30 min stages: pre-fight, fight-observed/fight-not-observed and post-fight. Demonstrator fish in white and focal fish in grey, belonging to four conditions: bystander dominant (BD), bystander subordinate (BS), control dominant (CD) and control subordinate (CS). At the post-fight stage, the side of winner (w) and loser (l) demonstrators is randomized. (d) Schematic of a focal fish's mean resultant directional vector, composed of the vector's length R and mean angle α(0° opposite and 180° directed towards the stimulus), and R projected onto 180° (Rproj).

Mentions: A test tank (13×13×17 cm) was placed facing a demonstrator tank (30×15×17 cm), with a one-way mirror in-between (figure 1a). This allowed for a bystander focal fish placed in the test tank to see a demonstrator fish pair, without itself being seen. It also prevented interactions between demonstrators and bystanders. No chemical communication was possible as the tanks were self-contained. The demonstrator tank was divided in half by a transparent partition. The outer half (buffer tank) buffered the fish from interference of spurious external cues and minimized stress from the experimenter's manipulations; the half adjacent to the test tank (demo tank) was further divided in two by an opaque removable partition and held the demonstrator fish. A top-view infrared sensitive (IRs) camera recorded the test tank and a front-view camera recorded the demonstrator tank. An IR custom-built lightbox increased contrast between the background of the test tank and the focal fish (when video recording from above) for offline tracking. The complete experimental set-up comprised four adjacent replicas of the described setting, one for each experimental condition.Figure 1.


Social dominance modulates eavesdropping in zebrafish.

Abril-de-Abreu R, Cruz AS, Oliveira RF - R Soc Open Sci (2015)

Social eavesdropping paradigm. (a) Three-dimensional diagram of the experimental set-up. Left wall coverings of the test and demo tanks are removed for easier visualization. (b) Timeline of experimental procedure. (c) Schematic of eavesdropping test (day 3), composed of three 30 min stages: pre-fight, fight-observed/fight-not-observed and post-fight. Demonstrator fish in white and focal fish in grey, belonging to four conditions: bystander dominant (BD), bystander subordinate (BS), control dominant (CD) and control subordinate (CS). At the post-fight stage, the side of winner (w) and loser (l) demonstrators is randomized. (d) Schematic of a focal fish's mean resultant directional vector, composed of the vector's length R and mean angle α(0° opposite and 180° directed towards the stimulus), and R projected onto 180° (Rproj).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555855&req=5

RSOS150220F1: Social eavesdropping paradigm. (a) Three-dimensional diagram of the experimental set-up. Left wall coverings of the test and demo tanks are removed for easier visualization. (b) Timeline of experimental procedure. (c) Schematic of eavesdropping test (day 3), composed of three 30 min stages: pre-fight, fight-observed/fight-not-observed and post-fight. Demonstrator fish in white and focal fish in grey, belonging to four conditions: bystander dominant (BD), bystander subordinate (BS), control dominant (CD) and control subordinate (CS). At the post-fight stage, the side of winner (w) and loser (l) demonstrators is randomized. (d) Schematic of a focal fish's mean resultant directional vector, composed of the vector's length R and mean angle α(0° opposite and 180° directed towards the stimulus), and R projected onto 180° (Rproj).
Mentions: A test tank (13×13×17 cm) was placed facing a demonstrator tank (30×15×17 cm), with a one-way mirror in-between (figure 1a). This allowed for a bystander focal fish placed in the test tank to see a demonstrator fish pair, without itself being seen. It also prevented interactions between demonstrators and bystanders. No chemical communication was possible as the tanks were self-contained. The demonstrator tank was divided in half by a transparent partition. The outer half (buffer tank) buffered the fish from interference of spurious external cues and minimized stress from the experimenter's manipulations; the half adjacent to the test tank (demo tank) was further divided in two by an opaque removable partition and held the demonstrator fish. A top-view infrared sensitive (IRs) camera recorded the test tank and a front-view camera recorded the demonstrator tank. An IR custom-built lightbox increased contrast between the background of the test tank and the focal fish (when video recording from above) for offline tracking. The complete experimental set-up comprised four adjacent replicas of the described setting, one for each experimental condition.Figure 1.

Bottom Line: We found that only dominant bystanders who had seen the fight revealed a significant increase in directional focus (a measure of attention) towards the losers of the fights.Furthermore, our results indicate that information about the fighters' acquired status was collected from the signalling interaction itself and not from post-interaction status cues, which implies the existence of individual recognition in zebrafish.We suggest that this type of integration of public and private information may be ubiquitous in social learning processes.

View Article: PubMed Central - PubMed

Affiliation: Instituto Gulbenkian de Ciência , Rua da Quinta Grande 6, Oeiras 2780-156, Portugal ; ISPA-Instituto Universitário , Rua Jardim do Tabaco 34, Lisboa 1149-041, Portugal ; Champalimaud Neuroscience Programme , Avenida de Brasilia , Lisboa 1400-038, Portugal.

ABSTRACT
Group living animals may eavesdrop on signalling interactions between conspecifics and integrate it with their own past social experience in order to optimize the use of relevant information from others. However, little is known about this interplay between public (eavesdropped) and private social information. To investigate it, we first manipulated the dominance status of bystander zebrafish. Next, we either allowed or prevented bystanders from observing a fight. Finally, we assessed their behaviour towards the winners and losers of the interaction, using a custom-made video-tracking system and directional analysis. We found that only dominant bystanders who had seen the fight revealed a significant increase in directional focus (a measure of attention) towards the losers of the fights. Furthermore, our results indicate that information about the fighters' acquired status was collected from the signalling interaction itself and not from post-interaction status cues, which implies the existence of individual recognition in zebrafish. Thus, we show for the first time that zebrafish, a highly social model organism, eavesdrop on conspecific agonistic interactions and that this process is modulated by the eavesdroppers' dominance status. We suggest that this type of integration of public and private information may be ubiquitous in social learning processes.

No MeSH data available.


Related in: MedlinePlus