Marine fish trait interactions give rise to unique ontogenetic movement combinations

Fish exhibit bipartite lifecycles, moving as both larvae and adults. Each life stage is influenced by diverse factors determining the structure of fish communities. While movement extents have known trade-offs, the factors affecting movement extents and their relationships between life stages are largely unknown. These interactions are vital to consider, for example, in designing conservation interventions and understanding species’ geographic distributions and ability to respond to change. Here, we created a Gaussian mixture model to organize 606 fish species into 6 distinct movement combinations based on their adult (home range size; HR) and larval (pelagic larval duration; PLD) movements. We then assessed key life-history characteristics as predictors of movement groupings. We found that (1) species generally exhibited a mid-range extent during at least 1 life stage, and (2) interactions between traits resulted in unique ontogenetic movement relationships, sometimes reversing expected outcomes; for example, in long-lived species, HR increased with length while PLD decreased, and in shorter-lived species, HR decreased with length while there was no relationship with PLD. Our findings highlight specific physiological and environmental contexts in which different movement combinations arise, leading to a better understanding of how different species groups may respond to their environments.