Data from: Within-group relatedness is correlated with colony-level social structure and reproductive sharing in a social fish.

In group-living species, the degree of relatedness among group members
often governs the extent of reproductive sharing, cooperation and conflict
within a group. Kinship among group members can be shaped by the presence
and location of neighbouring groups, as these provide dispersal or mating
opportunities that can dilute kinship among current group members. Here,
we assessed how within-group relatedness varies with the density and
position of neighbouring social groups in Neolamprologus pulcher, a
colonial and group-living cichlid fish. We used restriction
site-associated DNA sequencing (RADseq) methods to generate thousands of
polymorphic SNPs. Relative to microsatellite data, RADseq data provided
much tighter confidence intervals around our relatedness estimates. These
data allowed us to document novel patterns of relatedness in relation to
colony-level social structure. First, the density of neighbouring groups
was negatively correlated with relatedness between subordinates and
dominant females within a group, but no such patterns were observed
between subordinates and dominant males. Second, subordinates at the
colony edge were less related to dominant males in their group than
subordinates in the colony centre, suggesting a shorter breeding tenure
for dominant males at the colony edge. Finally, subordinates who were
closely related to their same-sex dominant were more likely to reproduce,
supporting some restraint models of reproductive skew. Collectively, these
results demonstrate that within-group relatedness is influenced by the
broader social context, and variation between groups in the degree of
relatedness between dominants and subordinates can be explained by both
patterns of reproductive sharing and the nature of the social landscape.