Prey capture analyses in the carnivorous aquatic waterwheel plant (Aldrovanda vesiculosa L., Droseraceae)

Abstract

We investigated the predator-prey interactions between an Australian ecotype of the carnivorous waterwheel plant (Aldrovanda vesiculosa, Droseraceae) and its potential natural prey, the water flea Daphnia longicephala (Daphniidae), which also occurs in Australia. A. vesiculosa develops snap-traps, which close within ~10–100 ms after mechanical triggering by zooplankton prey. Prey capture attempts (PCAs) were recorded via high-speed cinematography in the laboratory. From 14 recorded PCAs, nine were successful for the plant (the prey was caught), and five were unsuccessful (prey could escape), resulting in a capture rate of ~64%. The prey animals’ locomotion behaviour (antenna beat frequency and movement type) in trap vicinity or inside the open traps is very variable. Traps were mainly triggered with the second antennae. During trap closure, the animals moved only very little actively. A flight response in reaction to an initiated trap closure was not observed. However, several animals could escape, either by having a “lucky” starting position already outside the triggered trap, by freeing themselves after trap closure, or by being pressed out by the closing trap lobes. According to our observations in the successful PCAs, we hypothesize that the convex curvature of the two trap lobes (as seen from the outside) and the infolded trap rims are structural means supporting the capture and retention of prey. Our results are discussed in a broader biological context and promising aspects for future studies are proposed.

Facing the green threat: A waterflea’s defenses against a carnivorous plant

“…dubia not to be the only member of the Daphniidae family to thwart this "green threat" with inducible defenses. The carnivorous waterwheel plant (Aldrovanda vesiculosa) with snap-traps is 29 another aquatic predator for daphniids and other zooplankters (84,85). In fact, given the variety of carnivorous plants, their trapping principles and sometimes narrow prey spectra (86) there probably is a number of inducible defenses against them yet to be identified in different species and ecosystems.…”

“…another aquatic predator for daphniids and other zooplankters (84,85). In fact, given the variety of carnivorous plants, their trapping principles and sometimes narrow prey spectra (86) there probably is a number of inducible defenses against them yet to be identified in different species and ecosystems.…”

Self-Actuated Paper and Wood Models: Low-Cost Handcrafted Biomimetic Compliant Systems for Research and Teaching

“…The two trap lobes are connected by a midrib (arrow) and close because of the slight bending of the midrib but without curvature changes of the two trap lobes. Image modified after [ 37 ]. ( d ) The lily ( L.…”

Complexity and diversity of motion amplification and control strategies in motile carnivorous plant traps

“…Upon triggering, energetically costly turgor changes in motor zones flanking the midrib [58][59][60] initiate the release of pre-stress [49]. The midrib flexes downwards and the trap shuts [61]. In contrast to the Venus flytrap, the lobes do not change their curvature during this process, and their movement is mechanically coupled via the midrib.…”