Overview
- A peer-reviewed study published July 23 in Science combined bottom‑deployed sonar, anatomical dissection, and pressure‑chamber tests to study Chaoborus edulis larvae in Lake Malawi.
- Researchers tracked billions of larvae that sink more than 200 meters by day into an oxygen‑poor 'dead zone' to avoid predators and rise at night to feed.
- The team found the larvae repurpose part of their tracheal system into two pairs of tiny air sacs that act like ballast tanks to control depth.
- Air‑sac walls contain the elastic protein resilin, which expands or contracts when the larvae change the wall’s pH, letting the insects alter sac volume and buoyancy.
- Pressure tests showed the sacs resist the equivalent of more than 400 meters of depth, which weakens the idea that hydrostatic pressure alone keeps insects out of the open ocean and points to possible pH‑driven material‑science applications while leaving ecological barriers unresolved.