Active Sensing and Control Loops in Electric Fish Predation
This lecture explores the fascinating world of electric fish and their unique active sensing mechanisms for prey capture. It focuses on energy-emitting active sensing, detailing the detection range and the influence of prey signal characteristics, like those of Daphnia. We delve into the complexities faced by electric fish, including conspicuousness, prey and predator detection, and technological adaptation strategies such as ciphering and jamming avoidance. The lecture emphasizes the control loops involved in prey capture behavior, kinematics, and the evolutionary adaptations that enhance survival.
Active Sensing and Control Loops in Electric Fish Predation
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Presentation Transcript
ACTIVE SENSING Lecture 8 : Electric fish control loops ELECTRIC FISH
Course assistants • Erez Simony: erez.simony@weizmann.ac.il • Avi Saig: avi.saig@weizmann.ac.il Exercises Course list
Energy-emitting active sensing Geometry M. E. Nelson ֶ M. A. MacIver J Comp Physiol A (2006) 192: 573–586
Energy-emitting active sensing Frequency and duration ranges M. E. Nelson ֶ M. A. MacIver J Comp Physiol A (2006) 192: 573–586
Energy-emitting active sensing detection range Bat (detecting musquitoes) Dolphin (typical prey) Rat (contact range) Electric fish (daphnia) M. E. Nelson ֶ M. A. MacIver J Comp Physiol A (2006) 192: 573–586
The prey: Daphnia signal characteristics • Mechanosensory stimuli • Low-frequency bioelectric fields • Perturbations to the fish’s high-frequency electric field Daphnia 1 mm
Principle of active electrolocation M. E. Nelson
Prey capture kinematics Longitudinal velocity acceleration Distance to closest point on body surface
emitted-energy active sensing Complications with • conspicuousness • Detection of energy by prey and predators • confusion with peers
emitted-energy active sensing Adaptations specific to • conspicuousness • Detection of energy by prey and predators • confusion with peers • technology war • ciphering • jamming avoidance
Technology war make the probe less conspicuous to the prey/predator. Example: echolocating killer whales A dolphins echolocating killer whales B fish Dolphins can detect the ecolocating signals Fish cannot echolocating killer whales A use irregular short clicks echolocating killer whales B use continuous emission
Technology war make the probe less conspicuous to the prey/predator. Example 2: The prevalence of passive vision systems make it difficult for bioluminescence-based active photoreception to be a viable strategy in most ecological niches. Solution 1: Flaslight fish open and close a “lid” to expose their light organ briefly Solution 2: In deep sea, vision is usually based on the blue-green portion of the spectrum. deep-sea dragonfish have two bioluminescent organs, one of which produces a near infrared wavelength of light that only they can see.
Ciphering keep a private signal that allows decoding the echo Example: CF-FM echolocating bats 1st harmonic is weak and does not reach the peers 2nd harmonic is loud and also echoed well pairing of 2nd harmonic (source) & delayed 2ndharmonic (echo) would include peer calls These bats have evolved cells that respond to 1st harmonic & delayed 2nd harmonic other ciphering tricks?
Jamming avoidance Masashi Kawasaki Current Opinion in Neurobiology 1997, 7:473-479
Jamming avoidance WALTER METZNER, The Journal of Experimental Biology 202, 1365–1375 (1999)
emitted-energy active sensing Adaptations specific to • conspicuousness • Detection of energy by prey and predators • confusion with peers • technology war • ciphering • jamming avoidance
F d P What is the control loop? how to design a prey-capture loop P d F
F d P What is the control loop? how to design a prey-capture loop P d F
What is the control loop? how to design a prey-capture loop ? P d F K1 F d P
Prey capture kinematics Longitudinal velocity acceleration Distance to closest point on body surface
