14 research outputs found
Data from: Ovarian fluid allows directional cryptic female choice despite external fertilization
In species with internal fertilization, females can favour certain males over others, not only before mating but also within the female’s reproductive tract after mating. Here, we ask whether such directional post-mating (that is, cryptic) female mate choice can also occur in species with external fertilization. Using an in vitro sperm competition experiment, we demonstrate that female ovarian fluid (ovarian fluid) changes the outcome of sperm competition by decreasing the importance of sperm number thereby increasing the relative importance of sperm velocity. We further show that ovarian fluid does not differentially affect sperm from alternative male phenotypes, but generally enhances sperm velocity, motility, straightness and chemoattraction. Under natural conditions, female ovarian fluid likely increases the paternity of the preferred parental male phenotype, as these males release fewer but faster sperm. These results imply females have greater control over fertilization and potential to exert selection on males in species with external fertilization than previously thought possible
Alonzo_et_al_Nature_Comm_2016_Expt1
This file contains the data from Experiment 1 (the “in vitro” sperm competition experiments. These data are represented in Figures 1 and 2 and Tables 1 and 2
Data from: Species-specific patterns of nonapeptide brain gene expression relative to pair-bonding behaviour in grouping and non-grouping cichlids
Comparative studies have revealed that vasopressin-oxytocin pathways are associated with both pair bonding and grouping behaviour. However, the relationship between pair bonding and grouping behaviourremains unclear.In this study,our aim was to identify whether two species that differ in grouping behaviourdisplay a corresponding difference in their pair bonds, and in the underlying vasopressin-oxytocinhormonal pathways. Using two species of cichlid fishes, the highly social Neolamprologuspulcher and the non-social Telmatochromis temporalis, we measuredproximity of pairs during pair bond formation, and then measured social behaviors (proximity, aggression, submission,affiliation)and brain gene expression of isotocin and arginine vasotocin (the teleost homologues of oxytocin and vasopressin, respectively), as well as their receptors, after a temporary separation and subsequent reunion of the bonded pairs. Pairs of the social species spent more time in close proximity relative to the non-social species. Rates of aggression increased in both species following the separation and reunion treatment, relative to controls that were not separated.Overall, whole brain expression of isotocin was higher in the social species relative to the non-social species, and correlated with proximity, submission, and affiliation, but only in the social species. Our results suggest that both a social and a non-social cichlid species have similar behavioural responses to a temporary separation from a mate, and we found no differencein the brain gene expression of measured hormones and receptors based on our separation-reunion treatment. However, our results highlight the importance of isotocin in mediating submissive and affiliativebehaviourin cichlid fishes, and demonstrate thatisotocinhas species-specific correlations with socially relevantbehaviours
Alonzo_et_al_Nature_Comm_2016_Expt3
This file contains the data from Experiment 3 (the experiment examining the effect of ovarian fluid on sperm chemoattraction). These data are represented in Figure 4
Alonzo_et_al_Nature_Comm_2016_Expt2
This file contains the data from Experiment 2 (the experiment examining the effect of ovarian fluid on sperm characteristics). These data are represented in Figure 3
Rules of engagement for resource contests in a social fish
A rich theoretical framework exists for understanding animal conflict. When two opponents fight over a resource, the duration, intensity and outcome of the fight ought to be determined in large part by the relative difference in resource-holding power between contestants. While our understanding of one-time conflict resolution is excellent, our knowledge is still limited of how these rules scale up when contests occur in a social context where individuals have long-term interactions. Here, we use a convenient model system, Neolamprologus pulcher, a small cooperatively breeding cichlid fish, to explore decisions in pairwise contests over resources in a species where two individual contestants are likely to remain in the same social group, and regularly and repeatedly interact. Contests began after approximately 1 min, with a short display phase, and continued in an aphasic manner for an average of 10 min before a clear winner emerged. Information about opponents\u27 body size was important when deciding on the giving-up point, but contestants\u27 own body size was not, suggesting that assessment of opponent size is paramount in contest decision making. No sex differences were detected in contest structure, duration or intensity, and contests between males or between females were indistinguishable. These results offer an important window on conflict in a cooperative breeder and shed insight on rules of engagement within hierarchical social groups
Data from: Reproductive sharing in relation to group and colony-level attributes in a cooperative breeding fish
The degree to which group members share reproduction is dictated by both within-group (e.g. group size and composition) and between-group (e.g. density and position of neighbours) characteristics. While many studies have investigated reproductive patterns within social groups, few have simultaneously explored how within-group and between-group social structure influence these patterns. Here, we investigated how group size and composition, along with territory density and location within the colony, influenced parentage in 36 wild groups of a colonial, cooperatively breeding fish Neolamprologus pulcher. Dominant males sired 76% of offspring in their group, whereas dominant females mothered 82% of offspring in their group. Subordinate reproduction was frequent, occurring in 47% of sampled groups. Subordinate males gained more paternity in groups located in high-density areas and in groups with many subordinate males. Dominant males and females in large groups and in groups with many reproductively mature subordinates had higher rates of parentage loss, but only at the colony edge. Our study provides, to our knowledge, the first comprehensive quantification of reproductive sharing among groups of wild N. pulcher, a model species for the study of cooperation and social behaviour. Further, we demonstrate that the frequency of extra-pair parentage differs across small social and spatial scales