Game over: Conflict resolution through strategic growth in an invertebrate

In some multimember groups with unequal partitioning of reproduction and poor breeding opportunities outside the group, natural selection has favoured the evolution of adaptive mechanisms such as strategic growth modulation. Strategic growth is a form of body growth plasticity where individuals make growth adjustments calibrated to their closest competitor, establishing a size hierarchy that defines who has priority in reproduction. In this study we explored the occurrence of strategic growth in an invertebrate, the marine annelid worm Ophryotrocha puerilis, and investigated its underlying mechanisms via growth curve analysis. Size-matched juvenile worms exposed to different social environments established size hierarchies by following distinct developmental trajectories, with the intensity and duration of growth spurts correlated to the level of competition within their social environment. In monogamous environments, the onset of reproduction led to the weakening of the size hierarchy...., , , # Game over: Conflict resolution through strategic growth in an invertebrate Dataset DOI: [10.5061/dryad.mkkwh71bg](https://doi.org/10.5061/dryad.mkkwh71bg) ## Description of the data and file structure This dataset contains data from a 60-day laboratory experiment designed to investigate strategic growth in the polychaete worm *Ophryotrocha puerilis* in response to the social environment. Age- and size-matched juveniles were randomly assigned to one of four social environments (Isolation, Pairs, Triplets, or Groups with adults). Individual body size (segment count) and the timing of sex change (male to female) were monitored every 2-5 days throughout the experiment. We then analysed growth curve parameters to quantify the individual growth trajectories and examine the underlying mechanisms of strategic growth. By fitting a logistic model, we derived parameters (Asymptotic Size, Growth Rate, and Age at Inflection) to correlate the intensity and duration of individual growth adjustm...,