HomePhysicsSea Urchin Sperm Observe Their Noses

Sea Urchin Sperm Observe Their Noses

• Physics 15, s167

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


To breed, sperm cells from male sea urchins comply with weak chemical alerts by means of just a few 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 elucidate how sea urchin sperm navigate. Now Mahmoud Abdelgalil on the College of California, Irvine, and colleagues have found an sudden synergy between established sperm navigation fashions and ideas from management concept [1]. They developed a strong navigation mannequin that depends on a single parameter: the native focus gradient of the chemical the sperm cells observe. The crew says that their mannequin may very well be used to explain the movement of different organisms that transfer in response to chemical gradients.

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

Abdelgalil and colleagues confirmed that their strategy captures the sperm’s navigation dynamics and gives a less complicated interpretation of a “switching” conduct in its spiral swimming sample. Earlier fashions defined this conduct because the motion of two modes, switching between an “on-response” alongside the focus gradient and an “off-response” in some other route. Nevertheless, this work reveals that solely a single, dynamic mode is required to breed the anticipated swimming sample.

Abdelgalil says that their mannequin might assist researchers in designing robotic methods to have related sensing capabilities. “The methods at which nature arrived after years of evolutionary optimization current a promising place to begin to deal with these challenges for microrobots,” he says.

–Maggie Hudson

Maggie Hudson is an Affiliate Editor for Bodily Evaluation Supplies, Bodily Evaluation Utilized, and PRX Vitality.


  1. M. Abdelgalil et al., “Sea urchin sperm exploit extremum looking for management to search out the egg,” Phys. Rev. E 106, L062401 (2022).

Topic Areas

Statistical PhysicsBiological Physics

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