title: Fastest predators in the plant kingdom: functional morphology and biomechanics of suction traps found in the largest genus of carnivorous plants.
abstract: Understanding the physics of plant movements, which describe the interplay between plant architecture, movement speed and actuation principles, is essential for the comprehension of important processes like plant morphogenesis. Recent investigations especially on rapid plant movements at the interface of biology, physics and engineering sciences highlight how such fast motions can be achieved without the presence of muscles, nerves and technical hinge analogies. The suction traps (bladders) of carnivorous bladderworts (Utricularia spp., Lentibulariaceae, Lamiales) are considered as some of the most elaborate moving structures in the plant kingdom. A complex interplay of morphological and physiological adaptations allows the traps to pump water out of their body and to store elastic energy in the deformed bladder walls. Mechanical stimulation by prey entails opening of the otherwise watertight trapdoor, followed by trap wall relaxation, sucking in of water and prey, and consecutive trapdoor closure. Suction can also occur spontaneously in non-stimulated traps. We review the current state of knowledge about the suction trap mechanism with a focus on architectonically homogeneous traps of aquatic bladderwort species from section Utricularia (the so-called 'Utricularia vulgaris trap type'). The functional morphology and biomechanics of the traps are described in detail. We discuss open questions and propose promising aspects for future studies on these sophisticated ultra-fast trapping devices.
authors.affiliation: Plant Biomechanics Group, University of Freiburg, Botanic Garden, Schänzlestrasse 1, 79104 Freiburg im Breisgau, Germany Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, 79104 Freiburg im Breisgau, Germany simon.poppinga@biologie.uni-freiburg.de.
authors.forename: Simon
authors.initials: S
authors.lastname: Poppinga
authors.affiliation: Plant Biomechanics Group, University of Freiburg, Botanic Garden, Schänzlestrasse 1, 79104 Freiburg im Breisgau, Germany Present address: Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, Wissenschaftspark Potsdam-Golm, Am Mühlenberg 1, 14476 Potsdam, Germany.
authors.forename: Carmen
authors.initials: C
authors.lastname: Weisskopf
authors.affiliation: Plant Biomechanics Group, University of Freiburg, Botanic Garden, Schänzlestrasse 1, 79104 Freiburg im Breisgau, Germany.
authors.forename: Anna Sophia
authors.initials: AS
authors.lastname: Westermeier
authors.affiliation: Plant Biomechanics Group, University of Freiburg, Botanic Garden, Schänzlestrasse 1, 79104 Freiburg im Breisgau, Germany.
authors.forename: Tom
authors.initials: T
authors.lastname: Masselter
authors.affiliation: Plant Biomechanics Group, University of Freiburg, Botanic Garden, Schänzlestrasse 1, 79104 Freiburg im Breisgau, Germany Freiburg Materials Research Center (FMF), University of Freiburg, Stefan-Meier-Straße 21, 79104 Freiburg im Breisgau, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Speck
keywords: Biomechanics; Utricularia; bladderwort; carnivorous plant; functional morphology; prey; suction trap