Carnivorous plants trap and utilize animals in order to improve their supply with mineral nutrients. The complete process of prey utilization comprises four steps:
1. Attraction (using optical signals, scents or nectar)
2. Retention (using specialized leaves)
3. Degradation (by digesting the pray with enzymes) and
4. Uptake the soluble compounds.
All the plants that lack one of these features are called protocarnivorous.
The benefit of carnivory is an improved supply with minerals (phosphorus and nitrogen). This amazing plant adaptation enables the colonization of nutrient-poor habitats like peat bogs.
Five different strategies have been developed for prey retention:
- Adhesive traps, in which the pray is glued to the trap surface;
- Pitcher traps, with a cone shaped leaves, with smooth walls in which animals fall and drown in a poll of digestive fluid;
- Snap traps, in which the pray is enclosed upon touch;
- Suction traps produce a low hydrostatic pressure and the pray is sucked with the water upon stimulation;
- Tubular eel traps with inward pointing hairs that facilitate the way towards a digestive chamber but obstruct the way out.