title: Pre-start timing information is used to set final linear speed in a C-start manoeuvre.
abstract: In their unique hunting behaviour, archerfish use a complex motor decision to secure their prey: based solely on how dislodged prey initially falls, they select an adapted C-start manoeuvre that turns the fish right towards the point on the water surface where their prey will later land. Furthermore, they take off at a speed that is set so as to arrive in time. We show here that the C-start manoeuvre and not subsequent tail beating is necessary and sufficient for setting this adaptive level of speed. Furthermore, the C-start pattern is adjusted to independently determine both the turning angle and the take-off speed. The selection of both aspects requires no a priori information and is done based on information sampled from the onset of target motion until the C-start is launched. Fin strokes can occur right after the C-start manoeuvre but are not required to fine-tune take-off speed, but rather to maintain it. By probing the way in which the fish set their take-off speed in a wide range of conditions in which distance from the later catching point and time until impact varied widely and unpredictably, we found that the C-start manoeuvre is programmed based on pre-C-start estimates of distance and time until impact. Our study hence provides the first evidence for a C-start that is fine-tuned to produce an adaptive speed level.
authors.affiliation: Department of Animal Physiology, University of Bayreuth, Bayreuth 95440, Germany.
authors.forename: Caroline
authors.initials: C
authors.lastname: Reinel
authors.affiliation: Department of Animal Physiology, University of Bayreuth, Bayreuth 95440, Germany stefan.schuster@uni-bayreuth.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schuster
mesh_terms: D000818:Animals; D009068:Movement; D010473:Perciformes / Q000502:physiology*; D011235:Predatory Behavior; D013997:Time Factors
keywords: C-start; Decision-making; Motor output space; Motor programme; Time perception