# Collective movement shows over 300 evolutionary transitions across 2,839 ray-finned fish species

- Published: 2026-11-07 17:13 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: collective movement in fishes, ray-finned fishes evolution, Actinopterygii, collective behavior evolution, net diversification rate, predation pressure and grouping, patchy diet, macroevolution of fishes
- URL: https://realtech.media/news/rt-665750c1d1ad691b6ffcd502_collective_movement_shows/

**Authors quantified collective movement in 2,839 ray-finned fish species, nearly 10% of all extant ones, and linked it to predation pressure, patchy diets and higher net diversification rate.**

![Collective movement shows over 300 evolutionary transitions across 2,839 ray-finned fish species](https://realtech.media/media/2026/11/45bb7710864ba27f.jpg)
*Fred Hsu (Wikipedia:User:Fredhsu on en.wikipedia), Wikimedia Commons, CC BY-SA 3.0*

A research team has quantified collective movement phenotypes for 2,839 species of ray-finned fishes (Actinopterygii), nearly 10% of all extant species, according to a paper in Proceedings of the National Academy of Sciences. [1] Ray-finned fishes are the most species-rich class of vertebrates, and many of them move in groups. [1]

## Why group behavior is hard to place in evolution

Trait evolution and lineage diversification are usually explained by selection on the phenotypes of individual animals. Collective behavior is different: it appears only when individuals interact, and the resulting group-level phenotype can govern the fitness of each individual. [1] The authors state that it was unknown whether collective behaviors follow the same patterns of trait evolution as individual traits, and whether they have influenced macroevolutionary diversification. [1]

To score the species, the team used automated methods for text and image analysis. [1] Collective movement proved highly stable in some clades and extremely labile in others, with over 300 evolutionary transitions. [1] The authors describe collective behavior as widespread across the phylogeny of ray-finned fishes. [1]

## Predation, diet and diversification

Consistent with theoretical predictions, collective movement was associated with more patchy diets and with higher predation pressure. [1] In the significance statement, the authors describe this as a consistent correlation with experiencing higher predation pressure and with foraging for grouping prey. [1]

The evolution of collective movement coincided with an increase in the net macroevolutionary diversification rate. [1] Lineages that evolve collective movement show a higher net diversification rate than the others. [1]

The authors conclude that collective behavior is deeply intertwined with ecological and evolutionary dynamics across a vast phylogenetic scale. According to them, the result raises new questions about the role of collective phenotypes in shaping the diversity of life on Earth. [1]

## Sources

1. [Proceedings of the National Academy of Sciences](https://doi.org/10.1073/pnas.2611720123)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-665750c1d1ad691b6ffcd502_collective_movement_shows/