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HomeSciencePhysicsSea Urchin Sperm Follow Their Noses

Sea Urchin Sperm Follow Their Noses

• Physics 15, s167

Using ideas from management concept, researchers hyperlink the advanced navigation habits of a sea urchin sperm to a single parameter: its response to altering chemical “smells.”


To reproduce, sperm cells from male sea urchins observe weak chemical indicators by way of a couple of sq. meters of open ocean to succeed in and fertilize the eggs of females. Researchers throughout biology, physics, and arithmetic are fascinated by this phenomenon and have searched for easy fashions to clarify how sea urchin sperm navigate. Now Mahmoud Abdelgalil on the University of California, Irvine, and colleagues have found an surprising synergy between established sperm navigation fashions and ideas from management concept [1]. They developed a sturdy navigation mannequin that depends on a single parameter: the native focus gradient of the chemical the sperm cells observe. The staff says that their mannequin might be used to explain the movement of different organisms that transfer in response to chemical gradients.

The staff modeled the swimming habits utilizing an “extremum-seeking” method from management concept. In this method, the real-time response of an organism to some dynamic variable completely depends on the variable’s instantaneous native sign; the organism has no information of the sign throughout area and time.

Abdelgalil and colleagues confirmed that their method captures the sperm’s navigation dynamics and supplies a less complicated interpretation of a “switching” habits in its spiral swimming sample. Previous fashions defined this habits because the motion of two modes, switching between an “on-response” alongside the focus gradient and an “off-response” in another route. However, this work reveals that solely a single, dynamic mode is required to breed the expected swimming sample.

Abdelgalil says that their mannequin might assist researchers in designing robotic methods to have comparable sensing capabilities. “The strategies at which nature arrived after years of evolutionary optimization present a promising starting point to tackle these challenges for microrobots,” he says.

–Maggie Hudson

Maggie Hudson is an Associate Editor for Physical Review Materials, Physical Review Applied, and PRX Energy.


  1. M. Abdelgalil et al., “Sea urchin sperm exploit extremum seeking control to find the egg,” Phys. Rev. E 106, L062401 (2022).

Subject Areas

Statistical PhysicsBiological Physics

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