DOI: 10.5061/dryad.s4mw6m9bh
title: Data for: Multiple behavioral mechanisms shape development in a highly social cichlid fish

description: Early-life social experiences shape adult phenotype, yet the underlying
 behavioral mechanisms remain poorly understood. We manipulated early-life
 social experience in the highly social African cichlid fish Astatotilapia
 burtoni to investigate the effects on behavior and stress axis function in
 juveniles. Juveniles experienced different numbers of social partners in
 stable pairs (1 partner), stable groups (6 fish; 5 partners), and
 socialized pairs (a novel fish was exchanged every 5 days; 5 partners).
 Treatments also differed in group size (groups vs. pairs) and stability
 (stable vs. socialized). We then measured individual behavior and
 water-borne cortisol to identify effects of early-life experience. We
 found treatment differences in behavior across all assays: open field
 exploration, social cue investigation, dominant behavior, and subordinate
 behavior. Treatment did not affect cortisol. Principal components (PC)
 analysis revealed robust co-variation of behavior across contexts,
 including with cortisol, to form behavioral syndromes sensitive to
 early-life social experience. PC1 (25.1 %) differed by social partner
 number: juveniles with more partners (groups and socialized pairs) were
 more exploratory during the social cue investigation, spent less time in
 the territory, and were more interactive as dominants. PC5 (8.5 %)
 differed by stability: socialized pairs were more dominant, spent less
 time in and around the territory, were more socially investigative, and
 had lower cortisol than stable groups or pairs. Observations of the home
 tanks provided insights into the social experiences that may underlie
 these effects. These results contribute to our understanding of how
 early-life social experiences are accrued and exert strong, lasting
 effects on phenotype.
description: Juvenile <em>A. burtoni</em> body size was measured
 as mass (g) and standard length (mm). Length was measured at the very
 start of the experiment for all juveniles that could be included in the
 experiment. Length was measured from digital images with a ruler for scale
 using ImageJ. Individual identification was not feasible at this early
 developmental stage; therefore, these size data are not connected to
 behavior, hormone, or later size data. Mass and length were also measured
 at the end of the experiment, after the individual behavior assays.
 Behavior was video recorded in the home tanks and the individual behavior
 assays. In the home tanks, the total number of approaches, displacements,
 caroseling, fighting, lateral displays, entering the territory, and
 exiting the territory were scored using BORIS. Individual identification
 was not feasible in the home tanks. The individual behavior assays
 consisted of an open field exploration (OF), social cue investigation
 (SC), dominance behavior (Dom), and subordinate behavior (Sub) assays. In
 the OF and SC, the number of times entering each zone of the tank, and the
 time spent in each zone of the tank, was scored using BORIS. In the Dom
 and Sub assays, the number of approaches, displacements, approaches
 received, and submissions were scored using Solomon Coder (https://solomon.andraspeter.com/). The R package <em>compete</em> was used to calculate the directional consistency index (DCI) for the Dom and Sub assays, for patterns of approaching and displacing. This package was also used to calculate the dominance index David’s Score. The code was adjusted so that the calculation took both approaches and displacements into account when calculating dominance. Water-borne cortisol was collected after the behavior assays and quantified using enzyme-linked immunosorbent assays. Curley, J. P. (2016). <em>Compete: Analyzing competitive interaction data: R package version 0.1.</em> Friard, O., & Gamba, M. (2016). BORIS: a free, versatile open-source event-logging software for video/audio coding and live observations. <em>Methods in Ecology and Evolution</em>, 7(11), 1325–1330. Schneider, C. A., Rasband, W. S., & Eliceiri, K. W. (2012). NIH Image to ImageJ: 25 years of image analysis. <em>Nature Methods</em>, <em>9</em>(7), 671–675. doi:10.1038/nmeth.2089
description: Excel files
description: # Data for: Multiple behavioral mechanisms shape development in a highly
 social cichlid fish **“Initial_Fry_StandardLength.csv”** contains the
 standard length (mm) of juvenile *Astatotilapia burtoni* fish at
 approximately 7-days post-fertilization from each brood. Juvenile fish at
 this early developmental stage can be called “fry.” The experimental fish
 were selected from these individuals (data for these experimental fish is
 included below in “HomeTank_Behavior.csv” and
 “BehAssay_Hormone_Data.csv”). Descriptions of variables: * *BroodNumber*: 
 Arbitrary number assigned to broods of fish collected on the same day at
 the start of the experiment. *A. burtoni* (common name Burton’s
 Mouthbrooder) is a mouthbrooding fish, meaning mothers will keep the
 developing eggs in her buccal cavity (mouth) until they are fully
 developed. A brood is the group of juveniles that come out one mother’s
 mouth. * *StandardLength:* The standard length of the juvenile fish,
 measured from the tip of the jaw to the caudal peduncle (the point where
 the body meets the tail). Measured in mm using ImageJ.
 **“HomeTank_Behavior.csv”** contains behavior scored in the home tanks
 (also called the rearing environments), including the total number of
 approaches, displacements, carouseling, fighting, lateral displays,
 entering the territory, and exiting the territory. Descriptions of
 variables: * *HomeTank:* A unique identifier for each tank containing
 experimental fish during the rearing phase of the experiment. *
 *TestDate:* The date that behavior data were recorded. Behavior was
 recorded two times for each tank. * *Treatment:* This experiment tested
 the effects of early life experience on the social behavior and cortisol
 levels (a hormone involved in the stress response) of juvenile fish. The
 three treatments are: stable groups (“StableGroup”), stable pairs
 (“StablePair”), and socialized pairs (“SocializedPair”). In the stable
 groups, juveniles remained together for 5 weeks in groups of 6 fish. In
 the stable pairs, juveniles remained together for 5 weeks in groups of 2
 fish. In the socialized pairs, juveniles were always in a group size of 2
 fish, but every five days, one fish was removed from the tank and a novel
 fish was added. By the end of the 5 week rearing period, fish in the
 stable groups and socialized pairs had each experienced 5 unique social
 partners. Fish in the stable pairs only experienced 1 unique social
 partner. * *TotalApproaches:* For all of the fish in the social group, the
 total number of social approaches occurring during a 10 min observation
 period. An approach is defined as one fish swimming directly towards any
 part of another fish’s body, within 3 body lengths. *
 *TotalDisplacements:* For all of the fish in the social group, the total
 number of displacements occurring during a 10 min observation period. In
 response to an approach (see above), if the approached fish moves away
 from the approacher in any direction, that is scored as a displacement. *
 *Carousel_Fight:* For all of the fish in the social group, the total
 number of fights or instances of carouseling occurring during a 10 min
 observation period. A fight includes fish nipping or other physical
 contact with each other. Carouseling involves fish rapidly circling one
 another. Both fighting and carouseling may be a part of escalated
 aggressive behavior. * *LatDisplay:* For all of the fish in the social
 group, the total number of lateral displays occurring during a 10 min
 observation period. A lateral display involves fish lining up head to
 tail. Fins may be raised. The fish may swat each other with their tails or
 fins. The fish may turn slowly or quickly in a circle. A lateral display
 may lead to carouseling. * *TotalEscalatedAggression:* A summary metric of
 other escalated aggressive behavior occurring during the 10 min
 observation period. This includes fights, carouseling, and lateral
 displays. * *IntoTerritory:* In every tank, there was a small terracotta
 pot for a shelter / territory. Into the territory is a count of the total
 number of times any fish entered the territory (crossed into the pot with
 more than 50% of its body) during a 10 min observation period.   *
 *LeaveTerritory:* In every tank, there was a small terracotta pot for a
 shelter / territory. Leaving the territory is a count of the total number
 of times any fish exited the territory (crossed out of the pot with more
 than 50% of its body) during a 10 min observation period.
 **“BehAssay_Hormone_Data.csv”** contains behavior recorded in the
 individual behavior assays: an open field exploration (OF), social cue
 investigation (SC), dominance behavior (Dom), and subordinate behavior
 (Sub) assays. In the OF and SC, the number of times entering each zone of
 the tank, and the time spent in each zone of the tank, was scored using
 the free software BORIS. In the Dom and Sub assays, the number of
 approaches, displacements, approaches received, and submissions were
 scored. The R package *compete* was used to calculate the directional
 consistency index (DCI) for the Dom and Sub assays, for patterns of
 approaching and displacing. This package was also used to calculate the
 dominance index David’s Score. The code was adjusted so that the
 calculation took both approaches and displacements into account when
 calculating dominance. Water-borne cortisol was collected after the
 behavior assays and quantified using enzyme-linked immunosorbent assays.
 Descriptions of variables: * *HomeTank:* A unique identifier for each tank
 containing experimental fish during the rearing phase of the experiment. *
 *FishID:* Unique identifier for each fish undergoing individual behavioral
 testing. * *HormoneID:* Unique identifier for each fish’s hormone sample.
 * *Treatment:* This experiment tested the effects of early life experience
 on the social behavior and cortisol levels (a hormone involved in the
 stress response) of juvenile fish. The three treatments are: stable groups
 (“StableGroup”), stable pairs (“StablePair”), and socialized pairs
 (“SocializedPair”). In the stable groups, juveniles remained together for
 5 weeks in groups of 6 fish. In the stable pairs, juveniles remained
 together for 5 weeks in groups of 2 fish. In the socialized pairs,
 juveniles were always in a group size of 2 fish, but every five days, one
 fish was removed from the tank and a novel fish was added. By the end of
 the 5 week rearing period, fish in the stable groups and socialized pairs
 had each experienced 5 unique social partners. Fish in the stable pairs
 only experienced 1 unique social partner. * *NumberSocialPartners:* The
 number of social partners experienced by each individual. In general,
 stable pair fish experienced 1 social partner, while socialized paired
 fish and stable group fish experienced 5 social partners. If a fish died
 in the course of the experiment, it may have been replaced in the home
 tanks, thus exposing experimental fish to an additional social partner. *
 *TestTank:* Unique identifier for each experimental test tank. *
 *BehaviorTestDay:*  The individual behavior tests took place over 2 days:
 Day1 and Day2. * *FocalSL:* The standard length of the juvenile fish on
 the day of the individual behavior assays. Standard length is measured
 from the tip of the jaw to the caudal peduncle (the point where the body
 meets the tail). Measured in mm using ImageJ. * *FocalMass:* The mass (g)
 of the juvenile fish on the day of the individual behavior assays.
 *Behavior testing involved an open field exploration (OF), social cue
 investigation (SC), dominance behavior (Dom), and subordinate behavior
 (Sub) assays. In the OF and SC assays, we scored the number of times the
 focal fish entered each zone of the tank (territory, close, far, and
 investigate), and the time the focal fish spent in each zone of the tank,
 during a 10 min observation period.* * *OF_Close_Duration:* Time spent (s)
 in the close zone during the open field exploration. *
 *OF_Close_Frequency:* The number of times the focal fish entered the close
 zone during the open field exploration. * *OF_Far_Duration:* Time spent
 (s) in the far zone during the open field exploration. *
 *OF_Far_Frequency:* The number of times the focal fish entered the far
 zone during the open field exploration. * *OF_Investigate_Duration:* *Time
 spent (s) in the investigate zone during the open field exploration. *
 *OF_Investigate_Frequency:* The number of times the focal fish entered the
 investigate zone during the open field exploration. *
 *OF_Territory_Duration:* Time spent (s) in the territory zone during the
 open field exploration. * *OF_Territory_Frequency:* The number of times
 the focal fish entered the territory zone during the open field
 exploration. * *SC_Close_Duration:* Time spent (s) in the close zone
 during the social cue investigation. * *SC_Close_Frequency:* The number of
 times the focal fish entered the close zone during the social cue
 investigation. * *SC_Far_Duration:* Time spent (s) in the far zone during
 the social cue investigation. * *SC_Far_Frequency:* The number of times
 the focal fish entered the far zone during the social cue investigation. *
 *SC_Investigate_Duration:* Time spent (s) in the investigate zone during
 the social cue investigation. * *SC_Investigate_Frequency:* The number of
 times the focal fish entered the investigate zone during the social cue
 investigation. * *SC_Territory_Duration:* Time spent (s) in the territory
 zone during the social cue investigation. * *SC_Territory_Frequency:* The
 number of times the focal fish entered the territory zone during the
 social cue investigation. * *OF_CloseTerr_Frequency:* The number of times
 the focal fish entered the close + territory zones during the open field
 exploration. * *OF_FarInvest_Frequency:* The number of times the focal
 fish entered the far + investigate zones during the open field
 exploration. * *OF_CloseTerr_Duration:* *Time spent (s) in the close +
 territory zone during the open field exploration. *
 *OF_FarInvest_Duration:* *Time spent (s) in the far + investigate zones
 during the open field exploration. * *SC_CloseTerr_Frequency:* The number
 of times the focal fish entered the close + territory zones during the
 social cue investigation. * *SC_FarInvest_Frequency:* The number of times
 the focal fish entered the far + investigate zones during the social cue
 investigation. * *SC_CloseTerr_Duration:* Time spent (s) in the close +
 territory zone during the social cue investigation. *
 *SC_FarInvest_Duration:* Time spent (s) in the far + investigate zone
 during the social cue investigation. *In the dominance behavior and
 subordinate behavior assays, the focal fish was paired with a smaller
 “cue” fish (dominance) or a larger “cue” fish (subordinate).* *
 *Dom_CueMass:* Mass (g) of the cue fish paired with the focal fish in the
 dominance behavior assay. * *Dom_CueSL:* Standard length (mm) of the cue
 fish paired with the focal fish in the dominance behavior assay. *
 *Dom_cue_app:* The number of approaches by the cue fish to the focal fish
 in the dominance behavior assay in a 10 min observation period. *
 *Dom_cue_disp:* The number of displacements by the cue fish of the focal
 fish in the dominance behavior assay in a 10 min observation period. *
 *Dom_focal_app:* The number of approaches by the focal fish to the cue
 fish in the dominance behavior assay in a 10 min observation period. *
 *Dom_focal_disp:* The number of displacements by the focal fish of the cue
 fish in the dominance behavior assay in a 10 min observation period. *
 *Sub_CueMass:* Mass (g) of the cue fish paired with the focal fish in the
 subordinate behavior assay. * *Sub_CueSL:* Standard length (mm) of the cue
 fish paired with the focal fish in the subordinate behavior assay. *
 *Sub_cue_app:* The number of approaches by the cue fish to the focal fish
 in the subordinate behavior assay in a 10 min observation period. *
 *Sub_cue_disp:* The number of displacements by the cue fish of the focal
 fish in the subordinate behavior assay in a 10 min observation period. *
 *Sub_focal_app:* The number of approaches by the focal fish to the cue
 fish in the subordinate behavior assay in a 10 min observation period. *
 *Sub_focal_disp:* The number of displacements by the focal fish of the cue
 fish in the subordinate behavior assay in a 10 min observation period.
 *Directional consistency index (dci) is a measure of directional symmetry
 within a social group. A score of 0 indicates no directional asymmetry
 (i.e., perfect symmetry) in social interactions (approaches or
 displacements). A score of 1 indicates completely unidirectional (i.e.,
 perfectly asymmetrical) social interactions (approaches or
 displacements).* * *dom.dci_app:* Directional consistency index of
 approaches in the dominance behavior assay. * *dom.dci_displ:* Directional
 consistency index of displacements in the dominance behavior assay. *
 *dom.dci_app_pvalue:* Whether the DCI (based on approaches) of a social
 group (focal + cue fish) in the dominance behavior assay were
 significantly more directional than expected by chance (p&lt;0.05). *
 *dom.dci_displ_pvalue:* Whether the DCI (based on displacements) of a
 social group (focal + cue fish) in the dominance behavior assay were
 significantly more directional than expected by chance (p&lt;0.05). *
 *sub.dci_app:* Directional consistency index of approaches in the
 subordinate behavior assay. * *sub.dci_displ:* Directional consistency
 index of displacements in the subordinate behavior assay.            *
 *sub.dci_app_pvalue:* Whether the DCI (based on approaches) of a social
 group (focal + cue fish) in the subordinate behavior assay were
 significantly more directional than expected by chance (p&lt;0.05). *
 *sub.dci_displ_pvalue:* Whether the DCI (based on displacements) of a
 social group (focal + cue fish) in the subordinate behavior assay were
 significantly more directional than expected by chance (p&lt;0.05).
 *Social status in the dominance behavior assay and subordinate behavior
 assay was calculated for the focal and cue fish using David’s Score (DS).*
 * *Dom_Cue_DS.adj.Rank:* The social status (“dominant” or “subordinate”)
 of the cue fish in the dominance behavior assay. Status is based on
 David’s Score, with the higher David’s Score indicating dominance and the
 lower David’s Score indicating subordinate. * *Sub_Cue_DS.adj.Rank:* The
 social status (“dominant” or “subordinate”) of the cue fish in the
 subordinate behavior assay. Status is based on David’s Score, with the
 higher David’s Score indicating dominance and the lower David’s Score
 indicating subordinate. * *Dom_Focal_DS.adj.Rank:* The social status
 (“dominant” or “subordinate”) of the focal fish in the dominance behavior
 assay. Status is based on David’s Score, with the higher David’s Score
 indicating dominance and the lower David’s Score indicating subordinate. *
 *Sub_Focal_DS.adj.Rank:* The social status (“dominant” or “subordinate”)
 of the focal fish in the subordinate behavior assay. Status is based on
 David’s Score, with the higher David’s Score indicating dominance and the
 lower David’s Score indicating subordinate. * *Cue_dom.DS.adj:* David’s
 Score for the cue fish in the dominance behavior assay. *
 *Cue_sub.DS.adj:* David’s Score for the cue fish in the subordinate
 behavior assay. * *Focal_dom.DS.adj:* David’s Score for the focal fish in
 the dominance behavior assay. * *Focal_sub.DS.adj:* David’s Score for the
 focal fish in the dominance behavior assay. * *Cortisol:* Levels of the
 water-borne hormone cortisol measured in pg/mL/hr/g using enzyme-linked
 immunosorbent assay (ELISA).