ECC Blue Leg Hermit Crabs

Quick facts

Identity

Also known as

Blue Leg Hermit Crab; Scarlet Reef Hermit Crab; Red Reef Hermit Crab

Synonyms

Clibanarius tricolor (often sold under this name); Paguristes cadenati

Environment

Saltwater

Native to

Caribbean Sea, Western Atlantic Ocean

Habitat

Coral rubble, rocky reef flats, and shallow macroalgae beds where it forages among live rock and sand for algae and detritus.

Sourcing

Wild-caught

Conservation

Not Evaluated

Care

Care level

Easy

Temperament

Peaceful

Adult size

0.5 – 1.5 in (1.3 – 3.8 cm)

Lifespan

2 – 3 yrs

Min tank

10 gal (38 L)

Growth rate

Slow

Placement

Bottom, Rock & glass

Water

Temperature

75 – 80 °F (24 – 27 °C)

pH

8.1 – 8.4

dKH

8 – 11 dKH

Salinity

1.023 – 1.026 SG

Flow

Low-Moderate

Behavior & compatibility

Social

Group

Aggression to own kind

Low

Active

Daytime

Reef safe

Yes

Invert safe

With caution

Shrimp safe

With caution

Clean-up role

Algae, Detritus, Leftover food, Biofilm

Population boom risk

Low

Feeding & breeding

Diet

Omnivore

Foods

Algae, Frozen, Pellets

Breeding type

Broadcast spawner

Breeding difficulty

Not bred in captivity

Sexing

Sexes are not visually distinguishable without close examination of the underside; not practical for hobbyists to sex.

Target feeding

Beneficial

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Care guide

Overview

Collected from Caribbean rubble flats and macroalgae beds, this crab arrives with vivid blue legs and orange-tinted claws that make it easy to pick out on live rock. It stays active through the day, patrolling sand and rockwork for algae and detritus, and does best in groups with a steady supply of spare shells to prevent shell-stealing squabbles.

Care

This hermit crab is one of the easiest additions to a reef cleanup crew, tolerating the normal swings of an established marine tank as long as salinity and temperature stay stable. It spends most of daylight hours picking over rockwork and sand for algae films and leftover food, and it needs a mix of live rock crevices and open sand to move through comfortably. Because it must periodically molt and outgrow its shell, keep a supply of empty gastropod shells of varying sizes on hand at all times. Avoid copper-based medications in any tank housing this species, since copper is lethal to crustaceans even at doses considered fish-safe.

Feeding

In a mature reef system it typically finds enough film algae, cyanobacteria, and detritus to sustain itself without extra feeding. In newer or algae-poor tanks, supplement with sinking pellets, frozen mysis, or algae wafers a few times a week so it does not turn to picking at coral polyps or hunting snails out of hunger. It is an opportunistic omnivore and will scavenge almost any uneaten food that reaches the substrate.

Tank mates

Generally compatible with peaceful reef fish, most corals, and other invertebrates, though it may nip at soft coral tissue or polyps if underfed. The main friction point is competition for shells: without a steady supply of spare shells it may harass or kill snails and smaller hermits to take over their housing. Keep it away from large predatory crabs, mantis shrimp, triggerfish, and other animals that view small crustaceans as food.

Breeding

Breeding in home aquariums essentially never happens, since larvae go through a planktonic zoea stage that requires open ocean conditions to survive. Wild populations release eggs that hatch into free-swimming larvae before eventually settling and adopting their first tiny shell. Aquarium specimens are collected from the wild or aquacultured in large outdoor systems rather than bred in captive reef tanks.

Health

A crab that goes still and hides for a day or two is most likely molting rather than dying, and should not be disturbed or removed unless there is a clear smell of decay. Failed or incomplete molts are usually tied to unstable alkalinity, calcium, or iodine levels, so keeping these steady helps ensure a hard new exoskeleton forms properly. Sudden salinity or temperature swings are the most common source of stress-related deaths in otherwise healthy specimens.

Sources

1. Blue Leg Hermit Crab Invertebrate Care Guide | Top Shelf Aquatics
2. Blue Leg Hermit Crab Care: The Ultimate Reef Cleanup Crew Guide
3. ECC Blue Leg Hermit Crabs - Bulk Reef Supply
4. Scarlet reef hermit crab Aquarium Care | Atlarium

More Hermit crabs

Dwarf Red Tip Hermit CrabECC White Leg Hermit CrabsElectric Blue Hermit CrabGarmard's Hermit CrabHalloween Hermit CrabScarlet Reef Hermit Crabs