Many keepers of aquatic pets consider algae a nuisance. Left unchecked, algae can grow and multiply to unmanageable levels, which gives an aquarium a murky, unclean appearance.
Hermit crabs are algae eaters for aquariums, especially marine hermit crabs.
Terrestrial hermit crabs consider algae a food source. However, hermit crabs can’t be relied upon to manage algae in a tank single-handedly, and not all algae are safe or edible.
Hermit crabs should be encouraged to eat algae, which keeps an aquarium clean. Marine hermit crabs are nature’s janitors, so understand the different types of algae that hermit crabs like to devour.
What Are Algae?
Algae is the collective term for a group of alga.
Algae are most commonly found in bodies of water, although they also grow on wood, stone, and soil. Some algae even grow on animals’ skin and shells.
Algae are confused with plants, which is an easy mistake, especially aesthetically. Algae aren’t plants or fungi. Instead, as explained by Biosystems, algae belong to a group of organisms called protists.
Algae are critical to all living things, as they create oxygen.
Even marine animals, including aquatic hermit crabs, require oxygen to breathe. Algae also act as a food source for many marine lifeforms, including hermit crabs.
In some cases, you’ll need a microscope to detect algae. Left unchecked, algae can reach 200 feet or more. This is impossible in a home aquarium, but algae levels must be monitored.
Appropriate levels of algae in an aquarium are a positive thing. Algae organically filter water, provide food and oxygen, and replicate a marine animal’s natural habitat.
Think of algae as weeds on a lawn. They start small but can quickly grow, so keeping up with growth keeps an aquarium clean and aesthetically pleasing.
Hermit Crabs for Algae Control
Hermit crabs are scavengers. A hermit crab won’t hunt for food unless it’s essential.
Even then, it prefers to target small targets, like insects. Hermit crabs are almost always predators rather than prey, acting as bottom-feeders on the ocean floor.
This means that algae have become a natural food source for hermit crabs.
Marine species, which comprise most hermit crabs, are fond of algae. Terrestrial hermit crabs also eat algae, as it provides protein.
Hermit crabs also enjoy algae because they’re an easy, non-resistant meal.
According to the Journal of the Marine Biological Association of the United Kingdom, land hermit crabs gravitate toward a substrate covered with algae because it’s a plentiful food source.
Another reason hermit crabs enjoy algae is it doesn’t spoil. Hermit crabs like to eat little and often, as they can’t cope with gorging on a large meal. Algae provide a constant, reliable food source.
Many fish owners put hermit crabs in an aquarium as a natural algae clean-up crew. Fish specialists often sell hermit crabs under the banner’ algae eaters.’
In this regard, hermit crabs perform a similar role to snails in a fish tank.
Will Hermit Crabs Eat Algae Wafers?
If an aquarium lacks algae, consider adding algae wafers. These are most commonly offered to fish, so you’ll find them in exotic pet food stores.
Algae wafers are small discs created from compressed vegetables and dry algae.
Drop a wafer into an aquarium and stand back. Within a few seconds, the wafers will soften and sink to the bottom of the tank, where hermit crabs can consume them.
Algae wafers serve many purposes. They act as a food source and a treat should you wish to give hermit crabs something special. Also, algae wafers in water can kickstart the natural growth of more organic algae, leading to more food for your hermit crabs.
Serve algae wafers to marine hermit crabs sparingly, depending on the size of your aquarium.
A habitat that only hosts a handful of small hermit crabs or is less than 20 gallons in size should only receive half a wafer at a time.
Remember, hermit crabs don’t eat much, and if Left too long, the wafer will cloud the water in an aquarium. If you offer these wafers to land hermit crabs, remove anything uneaten after 24 hours.
Types of Algae for Hermit Crabs
With over 27,000 different species of algae, it’s impossible to profile them all. The algae profiled below are likely to be encountered by captive hermit crabs:
Bubble Algae
Bubble algae (Valonia ventricosa) is the largest unicellular organism. This algae is always present in natural water sources and is often found in home aquariums.
Bubble algae is a shiny green spherical growth. A single alga can grow to the size of a tennis ball, but this is uncommon in a tank. Nevertheless, bubble algae can grow to troublesome sizes.
Every time bubble algae bursts, thousands more are released into the water.
A hermit crab feasting on bubble algae is a blessing and curse. Hermit crabs may eat the algae, leading to more bubble algae. Every time algae are consumed, more are produced.
According to Scientific Reports, bubble algae are linked to the production of Chlorella vulgaris. This is a rich source of protein, commonly used as a food supplement in Asian cuisine.
Leave small amounts of bubble algae in an aquarium, but remove the majority by hand. Use tweezers or pliers, as bubble algae can be stubborn. Just don’t burst it in the process.
Green Hair Algae (String Algae)
Hair algae covers many organisms that resemble green, wet, and matted hair in an aquarium.
Hair algae grow and multiply quickly and can become unsightly. Many aquarium owners complain that hair algae block their view of the tank’s occupants.
Excessive iron in an aquarium is usually the cause of hair algae. Extreme light and insufficient nutrients can also lead to growth. Thankfully, most hermit crabs are keen eaters of hair algae.
Hair algae are best removed by scrubbing them with a toothbrush. Hermit crabs will handle the rest if you remove large clumps of hair algae. The answer to “Do hermit crabs eat hair algae?” is yes.
Brown Algae
These algae resemble a dusting of flour. You’ll likely see them all over a tank, covering walls, substrate, and decorations. Brown algae may not look pleasant, but they’re a delicacy to hermit crabs.
High amounts of phosphates and silicates cause brown algae in a tank.
It’s common in newly set up aquariums. If you have plants in your aquarium, they’ll absorb these minerals and minimize growth over time; hermit crabs will eat the rest.
To remove brown algae, wipe surfaces and perform spot cleaning.
Coralline Algae
Coralline algae are usually pink, although they can be a rainbow of shades. Colors include red, blue, yellow, purple, white, or gray. Whatever the hue, coralline algae should be welcomed.
These algae will dominate and outgrow other nuisance algae in an aquarium.
Many aquarium enthusiasts actively seek out coralline algae growth. They look pretty, clean the water, and provide a constant, healthy food source for marine life.
Coralline algae is rich in protein and flavorful, so hermit crabs will eat it. If you must remove coralline algae, empty the aquarium and dissolve it in vinegar.
Cyanobacteria
Cyanobacteria are technically not algae but bacteria. All the same, cyanobacteria are called ‘blue-green algae’ or ‘pond scum.’
Scientific American explains that cyanobacteria contain toxins that harm humans and wildlife. Thankfully, many hermit crabs will avoid eating these growths.
Changes in airflow or excess light cause cyanobacteria. Irregular cleaning of water will also lead to cyanobacteria. As uneaten food or waste dissolves, they become bacteria.
Cyanobacteria create a musty, earthy smell. If you notice this aroma in your aquarium, check for signs of these bacteria. Empty the aquarium and scrape away any growth. Then, treat the cause.
Red Slime Algae
Red slime algae are another form of cyanobacteria. You’ll find these algae in saltwater aquariums. Red slime algae can be invasive and unsightly, and poor water maintenance will lead to elevated growth.
Left untreated, red slime algae quickly multiply and spread, forming a layer on the aquarium. Hermit crabs may eat red slime algae, but not always.
Maintain an appropriate pH balance in your water to prevent red slime algae.
Change the water regularly, remove uneaten food or waste, and provide a regular current. If you observe the beginnings of red slime algae, remove it before it gains a foothold.
As bottom-feeding scavengers, hermit crabs will consume detritus found in an aquarium, and they’ll remain contented if other foods supplement the algae.
