Hermit crabs are detritivores, an animal that scavenges dead and decaying matter.
This animal is sometimes called a decomposer, an organism that breaks down dead matter. The difference is that decomposers eat matter that another animal has processed.
By eating decaying matter, hermit crabs recycle nutrients to enrich the soil and feed plants. Removing carcasses from the environment also keeps the area healthy.
Hermit crabs control dead matter in their local environment, so they play a critical role in the ecosystem. Aside from breaking down rotting matter, hermit crabs eat algae and prevent it from running wild.
Are Hermit Crabs Scavengers?
As stated, hermit crabs are omnivorous scavengers that eat various organisms.
These organisms include live and dead matter, depending on what’s available. Hermit crabs eat algae, decaying plant and animal matter, and microscopic organisms, like tiny clams and mussels.
Wild hermit crabs spend a large part of their day foraging for food.
Marine Biology noted that marine hermit crabs would soon discover and swarm carrion. A dozen or more hermit crabs will find their way to a carcass within half an hour of scent dispersal.
Hermit crabs eat whatever they can find, but all omnivorous animals prefer protein.
If you place a piece of fruit and meat in front of hermit crabs, they’ll almost always pick the meat. That said, if there isn’t much to choose from, hermit crabs aren’t overly fussy eaters.
Hermit crabs are known to eat:
- Fallen fruit
- Decaying leaf litter and wood
- Feces of other animals
Depending on where a hermit crab lives in the world, it’ll have access to whatever foods are local to the region. Living close to the water will mean it can access algae and debris from the sea.
Any dead animals that wash ashore are a meal. Hermit crabs are good climbers and will scale trees or jump piles in search of food.
Any decaying organic matter will draw hermit crabs, be it plant or animal, making them a crucial part of the food chain.
Are Hermit Crabs Also Decomposers?
Hermit crabs are considered decomposers and scavengers because they eat other animals’ leftovers, decaying matter, and forage for food. Ecology defines the difference between them as follows:
- Decomposers consume small particles produced by scavengers.
- Scavengers consume dead matter that another organism hasn’t yet processed.
With that in mind, decomposers can be hermit crabs. However, the more common decomposers are fungi, bacteria, and worms. Classing hermit crabs as decomposers or scavengers depends on the researcher’s stance or hermit crab species.
How Can Hermit Crabs Eat Rotten Meat?
Rotting matter is full of bacteria and other decomposers, which makes many animals sick. So, how do hermit crabs survive?
There’s little scientific research on how hermit crabs can eat decaying matter. However, studies have been performed on vultures, one of the most well-known scavengers in the world. These birds have a special mix of enzymes and strong stomach acids that kill bacteria in food.
Hermit crabs regularly consume decaying matter and seem to thrive on it, making it logical to assume that they have evolved stomach acids that can kill bacteria.
Are Hermit Crabs Producers or Consumers?
“Producers” are organisms that produce their own food, as with plants and photosynthesis.
“Consumers” are organisms that get their food from external sources, such as by eating plants or other animals. There are various types of consumers.
Hermit crabs are secondary consumers, so they scavenge the carcasses of other dead animals and:
There are no completely herbivorous hermit crabs. Only herbivores are primary consumers, which is why hermit crabs are classified as secondary consumers.
Why Are Decomposers Important?
Every animal plays an important part in the ecosystem it belongs to, from microscopic systems to macroscopic systems. Hermit crabs may be at the lower end of the food chain, but this doesn’t mean they’re unimportant.
Hermit crabs, like other scavengers, are nutrient recyclers. Hermit crabs process these nutrients by eating decaying matter and recycling them into a type of fertilizer. The waste of hermit crabs re-enters the soil to be absorbed by plants, which other animals will eat.
Decomposers do more than provide plants with fertile soil, though. They control waste, preventing bacterial outbreaks and surrounding water from becoming contaminated. In enriching soil, they also ensure that plants can grow in abundance.
Plants provide food for many animals and are critical in:
- Cycling oxygen into the water.
- Removing harmful chemicals and carbon dioxide.
Hermit crabs readily devour algae, like cyanobacteria and hair algae. They even consume the food sources of these organisms. Together, this prevents the family of organisms from growing out of control.
Certain types of algae, such as cyanobacteria, have been noted by Harmful Algae to impact water quality and food web resilience negatively. In controlling algae populations, hermit crabs help preserve a balance in their ecosystem.
What Would Happen If Hermit Crabs Disappeared?
Since hermit crabs play such an important role in their ecosystem, you may wonder what would happen if they disappeared.
We often wonder about the purpose of some animals, like flies or cockroaches, and why they exist. The truth is that every organism serves a purpose in its environment.
Decomposers and detritivores like hermit crabs play a critical role in the ecosystem. Sure, they’re not the only ones that can recycle dead matter.
Even so, hermit crabs share a responsibility that would otherwise overwhelm other creatures. They prevent an explosion in the vermin population and bacteria, which would unbalance their environment.
Other scavengers would fill their roles in places where hermit crabs live, but perhaps not as well. In the meantime, the dead matter would pile up and taint the environment.
The lack of organisms recycling those nutrients into the earth would lead to inferior soil quality. This impacts the plants and any animals that eat the plants. When there isn’t enough food for herbivores, they’ll move on or starve. This can lead to carnivores doing the same thing.
The collapse of an ecosystem can begin with one creature being removed. In the long term, it may recover, but there are parts of the ecosystem that may never return.
The above scenario may appear exaggerated, but it’s a reality in many places worldwide. Hermit crabs, as a detritivore, recycle dead matter and keep their environment healthy.