Blue Legged Hermit Crab: Overview & Care Guides

The tiny marine invertebrate known as the Blue Leg Hermit Crab is one that the decorative pet trade aggressively exploits.

They stand out from other higher crustaceans since their frail, brittle bodies are protected by movable houses made of snail shells.

They require much attention, and you must observe them to detect any potential health issues.

If you want to introduce some into your tank, let’s read this post to get an overview and care guides for this species.

Blue Legged Hermit Crab Overview

The following is a comprehensive overview of these crabs. Let’s keep reading!


This species has the scientific name Clibanarius tricolor. The western Atlantic and the Caribbean Sea are home to this widespread species.

On the south and north coasts of Curaçao, these creatures are highly prevalent at exposed coastlines and shallow seas of less than two meters.

During lower tides, these crabs gather in sizable temporary groups in the shallow waters, where they seek shelter in crevices between stones on stiff substrates.


This species may embed itself inside the mollusk shells scavenged thanks to their long, soft, spiral pattern coiled abdomens.

The form of their shells is not particularly significant since they replace them frequently when they become big for their original ones.

This species belongs to the Decapoda order, so they have ten appendages in addition to their claws.

Blue Legged Hermit Crab on rock



The typical home range of blue-legged hermit crabs is no more than 2 meters in diameter, and they have excellent site loyalty and little daily mobility.

It is a nocturnal species. The crabs rest or crawl slowly during the daylight hours. Dusk marks the start of the feeding activity, which lasts throughout the night.

Blue Leg Hermit crabs are gregarious and generally calm. They frequently gather in groups amid rocks that have been coated with debris.

These animals prefer to stay with their kind. They experience greater security and comfort as a result.

These creatures frequently lose their footing when trying to move over an obstruction and fall backward.

Nevertheless, these crabs can quickly correct themselves by moving the second legs.

The crabs often don’t change their behaviors whenever they see each other unless someone attacks them.


Crabs with blue legs have a 30-year lifespan in nature. When kept in a tank, they only survive for a median of 1 to 2 years.

Blue Legged Hermit Crab Care Guides

The Blue Leg Hermit Crab is highly well-liked because of its modest size and simplicity of maintenance.

They may make a fantastic complement to your reef aquarium. It’s crucial to constantly try to recreate a species’ native habitat in the aquarium.

If you want more guides, you can click on this video:

Tank Conditions

For a smaller school of 2 or 3 crabs, an aquarium with a minimum capacity of 10 gallons is essential.

Ideally, you should strive for only one crab every 3 to 4 gallons of water to prevent overcrowding the tank.

This species should live in water that is between 72 and 80 degrees Fahrenheit and has a pH of 8.0 to 8.5.

The water hardness in the tank should be from 8 to 16 °d, and the specific gravity should range from 1.020 – 1.025.

They enjoy slow-moving streams, despite their ability to withstand most water flow. Besides, you may use sand or tiny gravel as the substrate.

Since they often prefer to dwell in tidal sandy-bottom habitats, sand is the best substrate for them.

Moreover, they don’t require expensive filtration or illumination. Buy a standard aquarium light.

crab in tank


These crabs are scavengers. Thus they will consume practically everything they come across.

They consume dead animals such as shrimp, fish, and other natural decomposing debris, together with red and green algae.

Hermit crabs will aggressively pursue snails to consume them and obtain their shells.

They often make fantastic clean-up teams for any aquarium since they consume undesirable algae, including hair algae and red slime.

It’s crucial to provide your crabs with diverse food for healthy well-being, such as sinking vitamin-rich pellets.

It’s a good idea to feed your pets a smaller amount of food twice a day in the early morning and evening.

If your tank doesn’t have algae, you should provide them with a spirulina algae wafer or dried seaweed.

Besides, protein-rich foods like tuna and fresh sardines are excellent supplements for their daily diet.


The Blue Leg Hermit Crab gets along well with various aquatic creatures.

Even though they have robust shells, it is best to use caution while keeping them alongside other marine invertebrates that are more hostile.

You could keep them alongside peaceful fish and other similar tiny species like Tetras, Mollies, Zebra Blennies, or Guppies.

Avoid keeping snails in the same aquarium as these crabs since they may try to attack the smaller animals for the shells.


Breeding Blue Leg Hermit Crabs in captivity is a challenging task.

Due to the different salinity requirements of their larvae, it is hard to breed them in captivity.

Even scientists admit that they don’t fully understand how this species reproduces.


How Big Do Blue-Legged Hermit Crabs Get?

The maximum size of this species is 3/4 inches.

Are Blue-Legged Hermit Reefs Safe?

The well-known ability of these crabs to manage many kinds of algae, mainly hair algae, makes them widely regarded as reef-safe.

Are Blue-Legged Hermit Crabs Hardy?

Yes! They are undemanding and hardy pets you can keep in your aquarium.

Do Blue-Legged Hermit Crabs Need New Shells?

When crabs molt, they frequently crawl out of their shell. These aquatic creatures will regenerate their exoskeleton when they shed it.

It renders the hermit crab entirely exposed to heat, air, and light as it lacks a shell.

The Bottom Line

That’s all the essential information you should know about Blue Legged Hermit Crab before adding some to your aquarium.

In short, these creatures are relatively friendly and undemanding. Thus, if you are a novice aquarist, opt for this species.

If you have further questions, please comment below to let us know. Thanks for reading, and see you in the next post!