A comparative study across arthropods finds that sperm cooperation is far more widespread and evolutionarily recurrent than previously assumed.
In many insects, spiders, crustaceans and related animals, sperm bind into coordinated groups or use sperm-associated material to form organised structures. These arrangements may improve movement, protection or delivery through the reproductive tract. Mapping the trait across hundreds of species indicates that sperm conjugation has repeatedly appeared, disappeared and re-emerged, with evidence that the common ancestor of insects possessed conjugated sperm.
https://phys.org/news/2026-08-cooperative-approach-reproductive-success.html
