Most plants survive on nutrients in the soil, air and water. But some plants feed on prey to survive. “The venus flytrap” is one such plant that needs to supplement its diet by eating insects and arachnids.
The Venus flytrap (scientific name Dionaea muscipula) is a perennial plant, which means it can live for several years. Its flowers can bloom year after year. It is a photosynthetic and carnivorous plant and is estimated to live up to 20 years or more.
Like other plants, the venus flytrap also uses the process of photosynthesis to get energy from the sun. Venus flytraps feed on insects and arachnids to get nutrients that are not available in the surrounding environment. The plant is native to subtropical wetlands on the east coast of the United States.
Ever wondered how do venus flytraps work? This article highlights the mechanism this carnivorous plant adopts to catch and digest its prey, the methods by which the venus flytraps reproduce and the adaptations Venus flytraps have to catch prey.
Why do Venus flytraps catch prey?
The venus flytrap gets some of its nutrients from the soil but it had to turn carnivorous so that it could survive in the nutrient-poor soil of its native habitat in and around green swamps of North Carolina and South Carolina.
The venus flytrap plant grows in moist and acidic soil that has very poor nutritional content. In this harsh environment, they have an abundance of sunlight and water but the soil nutrients are very limited. To get the required nutrition, the venus flytrap lures insects and arachnids, into the jaws of its trap. The reddish interior of the trap and small glands across the rims that secrete nectar trick the insects into believing that it is a flower. It can lure ants, beetles, grasshoppers, flying insects, and even spiders to the flytrap.
The venus flytrap takes around 3 to 5 days to digest its prey, and it may go months before gobbling up its next meal.
Other carnivorous plants
Carnivorous plants are spread across the world but rather hard to find. Usually, they are entirely restricted to habitats such as swamps and bogs, where soil nutrients are extremely low but the sunlight and water are readily available. These extreme harsh conditions have forced these plants to adapt to become carnivorous for their survival.
Carnivorous plants grow in boggy wetlands where nutrient levels in the soil are very poor due to acidic conditions, high water content, and low oxygen levels, which all can lead to very slow decomposition of organic matter.
There are around 700 species of carnivorous plants that exist on the earth, some of them are
- Pitcher Plant
- Waterwheel plant
- Big Floating Bladderwort
- Monkey Cup
- Yellow Pitcher Plant
- Cobra Lily
- Australian Sundew
These carnivorous plants have developed a special and unique ability to capture their prey, decompose it and finally absorb the nutrients so that they can thrive in their environment where other plants struggle to survive.
The most common prey of carnivorous plants are small insects like ants, gnats, flies, bees, moths, grasshoppers, beetles, etc. Very rarely these carnivorous plants have been found to have preyed on frogs and small rodents as well.
Carnivorous plants lure insects to their traps with different tricks like color, scent, and nectar. The victim arrives with the promise of preying on something but itself gets preyed on.
Adaptations Venus flytraps have to catch prey
So how do venus flytraps work?
The venus flytrap and waterwheel plant are the only two carnivorous plants that use snap traps to catch their prey. The snap trap adaptation that a venus flytrap uses has evolved from an ancestral lineage that utilised flypaper traps (also termed as a fly ribbon, or flycatcher). Snap trap adaptation to catch the prey is also known as “mousetrap”, or “bear trap”, based on their shape and rapid movement.
The snap traps are made up of leaves whose terminal section is divided into two lobes that are hinged along the midrib. The venus flytrap has trigger hairs on the inner side of each lobe that are sensitive to touch. When a prey makes a contact with trigger hair, it bends which makes the signal to the lobes snap shut.
This action of flipping rapidly from convex to concave and interring the prey takes less than a second. The lobes require two stimuli, 0.5-0.30 seconds apart to snap shut the lobes. This mechanism is to prevent the snap trap response to raindrops and blown-in debris.
A 2009 study presented evidence that the snap traps mechanism used by the venus flytrap may have evolved from the flypaper traps used by its ancestor, Drosera. Pre-adaptations to the evolution of snap traps, like a rapid leaf and tentacle movement were identified in several species of Drosera.
The study suggests that snap traps evolved from flypaper traps to catch bigger prey that provides more nutritional value. But it was possible that large prey could easily escape the sticky mucilage (a thick, gluey substance produced by the plant) of flypaper traps resulting in the evolution of snap traps that would prevent prey from escaping and also prevent theft of prey before the plant can derive benefit from it.
How do Venus flytraps reproduce?
Venus flytraps can reproduce both sexually and asexually.
Like many other plants, the venus flytrap reproduces by creating seeds when their flowers are pollinated. The insects are attracted to the flowers and pick pollen from the stamen, the male part of the plant located at the tips of filaments of the flower and transfer it to the pistil, the female part of the flower located deep in the centre of the flower.
When the flower dies and falls down, its fertilized seeds are still alive. It takes around four to six weeks for the seed to mature. The mature seed is black in color and is pear-shaped. These seeds get spread across into the soil and grow into new plants.
The flower of the venus flytrap is located on top of a tall stock which helps to keep the pollinators away from the leaves and avoid getting trapped.
Venus flytraps can also reproduce asexually when its rhizomes extend horizontally in the soil and create a new bulb root. The new bulb root breaks away from the mother plant and grows into a new plant.
A Venus flytrap can reproduce asexually from the age of one or two years.
Optimal growing conditions for Venus flytraps
Before we answer the question “how do venus flytraps work?” it’s essential to look at the optimal conditions for venus flytraps.
The following conditions are required for optimal growth of Venus flytraps.
Venus Flytrap Light Conditions
The light should be bright but indirect, similar to sunlight is the best for growing venus flytraps. Avoid direct sunlight during summer if it gets too hot in your region, as it may make leaves turn crispy.
The plant should be kept 4-7 inches away from fluorescent lights if being grown under artificial lights.
More light is required if the traps don’t show a pink interior, or if the leaves look long and spindly.
Venus FlytrP Soil CONDITIONS
The Venus flytraps thrive in acidic and moist soil that has good drainage. Sphagnum or peat moss provides the best moisture retention and drainage which makes them the best soil for growing venus flytraps. A little amount of sand and/or orchid bark should be added to the soil. Some cultivators recommend that charcoal should be added to remove salts but fertilizer never should be added to the soil.
VENUS FLYTRAP Humidity CONDITIONS
The venus flytrap doesn’t require an extremely high humid environment, but above 50% humidity is good enough. The environment should be humid and the soil should stay moist but the plants should not stand constantly in water. Good air circulation is also required for growing venus flytraps.
VENUS FLYTRAP Temperature CONDITIONS
The temperature in the range of 70-95° F (21-35° C) is what suits Venus flytraps for growing. During winter, Venus flytrap enters dormancy when the temperature should not go below 40° F (5° C).
VENUS FLYTRAP WATER CONDITIONS
Rainwater or distilled water is the best. Tap water should be avoided as it is usually too alkaline or may contain too many minerals. The plant should stay damp, but not soaking in water. A container beneath the pot with about an inch of water in it to keep the humidity around the plant high and to keep the plant consistently moist is recommended for optimal growth.
The other factor that needs to be considered is the dormancy period of the venus flytrap. This occurs during winter, and usually lasts for about 3 months. During dormancy, usually, the tall large growth on it dies, leaving just a few small leaves or sometimes just its bulb. It is just a dormancy period and the plant is not actually dead so be plant should not be thrown away.
During dormancy, the temperature should be lowered and maintained so that it doesn’t go below 40° F (5° C). Regular check needs to be done to confirm no fungus is growing on the plant and it has not become too wet, which may cause it to rot.
How do Venus flytraps catch their prey?
The Venus flytrap catches its prey by performing the following two activities
Selecting the Prey
Like most carnivorous plants, venus flytraps selectively feed on prey based on its availability and that it can trap it. The venus flytrap preys on ants, grasshoppers, beetles, spiders and other crawling arthropods and very little on flying insects.
The Venus flytrap has evolved from an ancestral form of Drosera (the largest carnivorous plant genera). Drosera uses a sticky trap mechanism to catch its prey instead of the snap trap mechanism that venus flytraps use. Drosera prey on smaller, aerial insects, whereas the venus flytraps prey on terrestrial insects. Venus flytraps are able to extract more nutrients from these larger insects, giving them an evolutionary advantage over carnivorous plants that uses sticky trap.
Trapping The Prey
The venus flytrap belongs to a very small group of plants that are capable of rapid movement. It uses a snap trap mechanism to trap its prey. The snap trap mechanism is a complex interaction between elasticity, turgor and growth to snap shut to trap the prey.
The trap only closes when there have been two stimuli of the trigger hairs within a span of 0.5-30 seconds. This is to avoid inadvertent triggering of the mechanism by raindrops, dust or any other wind-borne debris. When the trigger hairs (sensory hairs) are stimulated, an electrical signal is generated which spreads out the lobes and stimulates the cells in the lobes and midrib. The electrical signal that gets generated is the result of the movement of charged atoms, called ions, across the membranes of cells within the lobes.
When the second electrical signal is generated, cells in the centre of each lobe and midrib lose water along with the ions, causing the cells to lose turgor, the water pressure that keeps a plant rigid. As a result, the lobes change from convex (bent outwards) to concave (bent inwards) form, resulting in shutting down of the trap and creating a stomach like cavity to trap the prey. The prey is often lured in by the sweet scent of the nectar.
Venus flytraps also exhibit an example of memory in plants. When the first stimulus happens on prey touching one of the trigger hairs, the plant remembers this for a few seconds and waits for the second stimulus to happen. If the second stimulus occurs within the timeframe, the venus flytrap snaps shut the trap. After shutting down the trap, the venus flytrap counts for additional five stimulations of the trigger hairs before starting the production of enzymes to digest its prey.
How do Venus flytraps digest their prey?
When answering the question, how do venus flytraps work, it’s essential we look at how venus flytraps digest their prey.
The venus flytrap has one of the quickest plant movements to catch its prey. It then uses a cocktail of enzymes to digest its prey.
The prey while trying to escape from the trap continues to move, which stimulates the inner surfaces of the lobes forcing the outer edges to seal the trap hermetically and forms a “stomach” where the digestion takes place.
Once the prey is trapped inside the “stomach”, the plant will emit pre-digestive enzymes from special glands to dissolve the tough outer exoskeleton of its prey. Once the tougher exoskeleton is broken through, oxidative protein modification starts, resulting in rupturing of animal cell membranes, which makes them more susceptible to proteolysis.
Proteolysis is the process of breaking down proteins into smaller polypeptides or amino acids by intra-molecular digestion. This is followed by the processing of the haemolymph, nitrogen-rich blood-like fluid of the prey.
Venus flytraps usually takes about ten days to digest its prey, after which the prey is reduced to a husk of chitin – a modified carbohydrate (polysaccharides) comprising of nitrogen. It is a major constituent in the exoskeleton of the prey. The trap reopens once the digestion is complete, and is ready for reuse.
Conclusion: How Do Venus Flytraps Work?
We hope we answered the question – How do venus flytraps work?
The Venus flytrap is a fascinating carnivorous plant that uses a snap trap mechanism to catch its prey. Venus flytraps feed on insects to supplement their diet with nutrients that are not available in the soil that it grows in.
It can be grown in a deep pot at home, but it does require growing conditions that are similar to its natural habitat.
If you enjoyed our article on how venus flytraps work, share it by hitting the button below.