For over a century, scientists have sought to understand how fish orient against an incoming flow, even without visual and flow cues. In a study published in eLife, researchers explore a potential hydrodynamic mechanism of fish rheotaxis—movement away or toward water currents—through the study of the bidirectional coupling between fish and the surrounding fluid. [1]

Figure 1. Hydrodynamic model of fish orientation in a channel flow

Figure 1 shows the researchers note that the main contribution of the proposed model is treatment fish as an invasive sensor that simultaneously responds to background flux and impacts, thereby establishing interactions between fish and the environment. [2]

By modeling a fish as a vortex dipole, a jet-flow with a system of two vortices, in an infinite channel with an imposed background flow, they established a dynamical system that captures the existence of a critical flow velocity. for the fish to successfully orient while executing periodic cross sweeping motions. [3]

The researchers placed their models alongside experimental observations in the literature on the rheotactic behavior of fish without visual and lateral line cues. The critical role of bidirectional hydrodynamic interactions revealed by this model points to an overlooked limitation of existing experimental paradigms to study reotaxis in the laboratory. [4]

References:

1. https://phys.org/news/2022-06-hydrodynamic-fish-channel.html
2. https://industry-update.com/hydrodynamic-model-of-fish-orientation-in-the-channel/55946/
3. https://news.postuszero.com/news/61509/Hydrodynamic-model-of-fish-orientation-in-channel-flow-%E2%80%93-.html
4. https://whatsnew2day.com/hydrodynamic-model-of-fish-orientation-in-a-channel-flow/

Cite this article:

Thanusri swetha J (2022), Hydrodynamic model of fish orientation in a channel flow, Anatechmaz, pp.84