Pom Pom Crab

Quick facts

Identity

Also known as

Boxer Crab; Cheerleader Crab

Environment

Saltwater

Native to

Red Sea, East Africa, Indo-Pacific, Indonesia, New Guinea, Japan, Hawaii

Habitat

Shallow reef flats and rubble zones, sandy or gravelly seabeds, and among live coral where it clings with its long legs

Sourcing

Wild-caught

Conservation

Not Evaluated

Care

Care level

Moderate

Temperament

Peaceful

Adult size

0.5 – 1 in (1.3 – 2.5 cm)

Lifespan

1 – 3 yrs

Min tank

10 gal (38 L)

Growth rate

Slow

Placement

Bottom

Water

Temperature

75 – 80 °F (24 – 27 °C)

pH

8.1 – 8.4

dKH

8 – 12 dKH

Salinity

1.023 – 1.025 SG

Flow

Low-Moderate

Behavior & compatibility

Social

Solitary

Aggression to own kind

Moderate

Active

Night

Reef safe

With caution

Invert safe

With caution

Shrimp safe

With caution

Clean-up role

Detritus, Leftover food

Population boom risk

Low

Feeding & breeding

Diet

Omnivore

Foods

Frozen, Micro-pellets, Zooplankton

Breeding type

Larval (brackish)

Breeding difficulty

Not bred in captivity

Sexing

Females carry red eggs brooded on the underside of the abdomen; otherwise sexes look alike externally

Target feeding

Required

Something wrong or missing? Submit a correction

Care guide

Overview

Populations across the Red Sea, Indo-Pacific, and Hawaii supply the trade with this mottled white-to-tan xanthid, prized for the pair of anemones it waves in each claw. It stays tucked in rubble and rock crevices, emerging mainly to feed or defend territory. Small and easily outcompeted, it needs target feeding and a well-sealed, mature nano reef.

Care

This tiny xanthid crab spends most of its time tucked into crevices in live rock or rubble, emerging mainly to feed or defend its territory. It does best in a mature, well-established nano reef with plenty of small rock crevices and low to moderate flow so it can hold its anemones without being buffeted. Because it is so small and easily outcompeted, it should not be kept with fast, aggressive tankmates, and the tank must be well sealed since it can slip through very small gaps. Stable salinity, temperature, and pH are important, as this species does not tolerate rapid swings well.

Feeding

In the wild the crab cannot feed itself directly and instead uses the stinging tentacles of the small anemones in its claws to snag food particles, which it then transfers to its mouthparts. In captivity it should be target-fed several times a week with finely minced meaty foods such as mysis shrimp, chopped clam, or fish, released close to its hiding spot with a pipette or turkey baster. Without direct feeding it can be easily outcompeted by faster tankmates and slowly starve, so consistent supplemental feeding is important even in tanks with decent detritus levels.

Tank mates

Best paired with peaceful, non-predatory fish and invertebrates that will not view it as prey, such as small gobies, firefish, and snails. Avoid hawkfish, larger wrasses, triggers, puffers, lionfish, dottybacks, and large or aggressive shrimp such as coral banded shrimp, all of which may harass or eat it. The anemones it carries can sting sessile invertebrates and coral polyps if the crab wanders too close, so give it distance from delicate sessile life in the aquascape.

Breeding

Females brood red eggs on the underside of the abdomen after mating, and larvae are released into the water column as free-swimming zoea. Rearing the planktonic larval stages in a home aquarium is not practical and this species is essentially never bred in captivity by hobbyists. Any offspring seen in a reef tank are typically incidental and unlikely to survive to a visible size without dedicated larval culture.

Health

Most problems trace back to poor acclimation, sudden salinity or temperature swings, or exposure to copper-based medications, which are lethal to this and all crustaceans. A failed molt, indicated by lethargy, an inability to fully shed the old exoskeleton, or lost limbs, is often a sign of nutritional stress or unstable water parameters. Drip acclimation and a stable, mature system with consistent feeding help avoid these issues.

Sources

1. Lybia tessellata - Wikipedia
2. Pom Pom Crab Invertebrate Care Guide | Top Shelf Aquatics
3. Pom-pom Crab (Lybia tessellata) – Complete Care Guide | Reeflings
4. Pom-pom crab (Lybia tessellata) Aquarium Care | Atlarium