zyntrax

Put giant danio in a tank and build a maze out of water: an array of jets makes fast, turbulent lanes next to slow, calm ones, each a few fish-lengths wide.

When a fish hits a jet it doesn't swim straight out. It turns its body about 25 to 30 degrees to the flow and drifts sideways, moving nearly 90 degrees off its own heading. It rides lift instead of fighting drag, and the measured lateral force scales the way that model predicts.

The good part is the ceiling. The scaling breaks near 38 degrees (+/-8), close to the roughly 45 degrees where simulations say a fish body stalls. The fish's preferred angle is about 25 degrees, a standard deviation under stall. Angle harder and the flow separates: less lift, more drag. So it holds just under the limit.

A second, speculative thread: the same yaw sharpens the left-right pressure difference the lateral line reads, so the posture that moves the fish might also help it sense the flow. Model, not measurement.

Calicchia & Ni, PNAS, doi 10.1073/pnas.2613565123. Read the accepted manuscript on arXiv (2609.09024). Caveat: the behavior is measured; the mechanism is argued from scaling, not from a simulation of a swimming fish.