Some Sperm Don't Race. They Row as a Crew.

Across the arthropods, the vast group holding spiders, crabs, centipedes and insects, sperm often skip the scramble for the egg. They link up and travel in coordinated groups, pulling together like a rowing eight. Evolution has invented, abandoned and reinvented this arrangement over 500 million years.

A team from Syracuse University, the University of Siena and the University of Szeged calls it sperm conjugation. First described over a century ago, it was long filed away as a rarity. Their analysis in Nature Communications pulled sperm data from decades of studies on hundreds of species and mapped each trait onto a family tree. The results suggest the behavior is common and keeps arising independently. By their reconstruction, the shared ancestor of every insect had conjugated sperm.

Often the binding agent is a membrane-wrapped substance called sperm-associated material, or SAM. It can stick cells together or build an outer scaffold that herds them into formation. The team suspects SAM began as wrapping or shielding and may have helped conjugation get started.

The study left open why cells would team up. Groups might swim better or ferry useful molecules to the right spot, but sperm on a microscope slide behave differently than inside a female's body, so those ideas were hard to test.

Then there is the spotted lanternfly, an invasive pest menacing farms across New York and the East. Its sperm never group up. Each one is sealed in a thick coat of SAM, and the researchers could not explain how the cells move. If that coating is essential, disrupting it could offer a targeted way to control the pest.

Plenty of arthropods send their sperm out in rowing crews. The lanternfly zips each one into its own sleeping bag.

Read the full story at Syracuse University News, August 4, 2026

Hot Take: Lanternflies, whose sperm move by means the researchers could not explain, belong in the same filing cabinet as the stork.