Facing the Green Threat: A Water Flea’s Defenses against a Carnivorous Plant

Every ecosystem shows multiple levels of species interactions, which are often difficult to isolate and to classify regarding their specific nature. For most of the observed interactions, it comes down to either competition or consumption. The modes of consumption are various and defined by the nature of the consumed organism, e.g., carnivory, herbivory, as well as the extent of the consumption, e.g., grazing, parasitism. While the majority of consumers are animals, carnivorous plants can also pose a threat to arthropods. Water fleas of the family Daphniidae are keystone species in many lentic ecosystems. As most abundant filter feeders, they link the primary production to higher trophic levels. As a response to the high predatory pressures, water fleas have evolved various inducible defenses against animal predators. Here we show the first example, to our knowledge, in Ceriodaphnia dubia of such inducible defenses of an animal against a coexisting plant predator, i.e., the carnivorous bladderwort (Utricularia x neglecta Lehm, Lentibulariaceae). When the bladderwort is present, C. dubia shows changes in morphology, life history and behavior. While the morphological and behavioral adaptations improve C. dubia’s survival rate in the presence of this predator, the life-history parameters likely reflect trade-offs for the defense

Supplementary Video 4 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

FE-Model 3 - detailed stress distribution in x- direction (up) and y-direction (low). Apical and lateral view

Supplementary Video 7 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

FE-Model 3 - At top: anisotropic turgor change (parallel to midrib) in inner epidermis. Apical and lateral view. At Bottom: anisotropic turgor change (parallel to midrib) in whole thickness. Apical and lateral view

Supplementary Video 1 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

Trap closure of <i>Aldrovanda vesiculosa</i>. Apical and lateral view. Recording speed 1000 fps

Supplementary Video 9 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

FE-Model 3 - combined prestress and turgor load case. Apical and lateral view

Video S3 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

FE-Model 2 - prestress assumption derived from manipulation experiments. Apical and lateral view

Video S1 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

Trap closure of <i>Aldrovanda vesiculosa</i>. Apical and lateral view. Recording speed 1000 fps

Supplementary Video 3 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

FE-Model 2 - prestress assumption derived from manipulation experiments. Apical and lateral view

Video S6 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

FE-Model 3 - At top: isotropic turgor change in inner epidermis. Apical and lateral view. At bottom: isotropic turgor change in whole thickness. Apical and lateral view

Video S5 from How the carnivorous waterwheel plant (<i>Aldrovanda vesiculosa</i>) snaps

FE-Model 1 - temperature (=turgor) load case. Apical and lateral view