title: Agonistic reciprocity is associated with reduced male reproductive success within haremic social networks.
abstract: While individual variation in social behaviour is ubiquitous and causes social groups to differ in structure, how these structural differences affect fitness remains largely unknown. We used social network analysis of replicate bluebanded goby (Lythrypnus dalli) harems to identify the reproductive correlates of social network structure. In stable groups, we quantified agonistic behaviour, reproduction and steroid hormones, which can both affect and respond to social/reproductive cues. We identified distinct, optimal social structures associated with different reproductive measures. Male hatching success (HS) was negatively associated with agonistic reciprocity, a network structure that describes whether subordinates 'reciprocated' agonism received from dominants. Egg laying was associated with the individual network positions of the male and dominant female. Thus, males face a trade-off between promoting structures that facilitate egg laying versus HS. Whether this reproductive conflict is avoidable remains to be determined. We also identified different social and/or reproductive roles for 11-ketotestosterone, 17β-oestradiol and cortisol, suggesting that specific neuroendocrine mechanisms may underlie connections between network structure and fitness. This is one of the first investigations of the reproductive and neuroendocrine correlates of social behaviour and network structure in replicate, naturalistic social groups and supports network structure as an important target for natural selection.
authors.affiliation: Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA tksolomonlane@utexas.edu.
authors.forename: Tessa K
authors.identifier: http://orcid.org/0000-0001-7422-462X
authors.initials: TK
authors.lastname: Solomon-Lane
authors.affiliation: Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Devaleena S
authors.identifier: http://orcid.org/0000-0002-7755-2538
authors.initials: DS
authors.lastname: Pradhan
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30302, USA.
authors.forename: Madelyne C
authors.initials: MC
authors.lastname: Willis
authors.affiliation: Department of Biology, Georgia State University, Atlanta, GA 30302, USA Neuroscience Institute, Georgia State University, Atlanta, GA 30302, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Grober
mesh_terms: D000378:Agonistic Behavior; D000818:Animals; D004958:Estradiol / Q000378:metabolism; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D006854:Hydrocortisone / Q000378:metabolism; D008297:Male; D010473:Perciformes / Q000502:physiology*; D012098:Reproduction; D012726:Sexual Behavior, Animal; D012919:Social Behavior; D013739:Testosterone / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D012739:Gonadal Steroid Hormones; D013739:Testosterone; D004958:Estradiol; C003600:11-ketotestosterone; D006854:Hydrocortisone
keywords: agonistic behaviour; reciprocity; reproductive conflict; reproductive success; social network