Not furry either, still lovely.
Pom Pom Crab
Lybia tessellata
Also called Boxer crab, Cheerleader crab, Pom-pom crab
From Shallow tropical Indo-Pacific, from the Red Sea and East Africa to Indonesia and New Guinea, north to Japan and east to Hawaii.1
At a glance the quick version
Wikipedia gives a carapace width of about 2.5 cm; LiveAquaria lists a maximum of 1 in (about 2.5 cm).
Looks how to spot one
Hard exoskeleton
A tiny crab whose shell is covered in a web of dark lines over a pale background, giving a stained-glass look. The legs are striped with dark bands and dotted with white. In each claw it usually holds a small living sea anemone.12
Personality what they are like
Shy and peaceful. When it feels threatened it waves its anemones toward the intruder like boxing gloves. It is easiest to spot at night once the tank lights are off.123
Daily activity how busy a day looks
A small, secretive crab that moves around rocks and gravel, mostly after dark, dabbing its anemones on surfaces to collect food.12
Grooming and care the hands-on bits
Rated easy. LiveAquaria recommends keeping calcium, magnesium, iodine and trace elements at reef levels. Its anemones can lightly touch nearby corals, but LiveAquaria notes any effect is small because the anemones are tiny.2
Home where they are happiest
A marine aquarium with rockwork and sand or gravel where it can hide. LiveAquaria gives 72-78 °F (about 22-26 °C), pH 8.1-8.4, dKH 8-12 and specific gravity 1.020-1.025. Wild crabs live on sandy, gravelly bottoms and among live corals in shallow water. No minimum tank size was given by the sources.21
Food basics what goes in the bowl
An omnivore that gathers food using the tentacles of its anemones and passes it to its mouth. In aquariums, offer small meaty foods such as mysis shrimp, chopped fish and clam.12
Company who they like around
Best with peaceful tankmates that will not outcompete it at feeding time. The sources give no guidance on keeping several together.2
The story where it all began
Latreille named this crab in 1812. Its habit of holding anemones was first noted by Möbius in 1880, and studies since 2013 have looked closely at how the crab and its anemones share food and protection.13
Fun facts for the dinner table
- 1
If it loses one anemone, the crab can pull the remaining one in two, and each half regrows into a full anemone (Schnytzer et al., 2017).3
- 2
It cannot feed well with its own claws, so it uses the anemone tentacles like little mops to pick up food.1
- 3
The 'boxer' name comes from the way it jabs its anemones at rivals as if wearing boxing gloves.3
- 4
Females carry bright red eggs under the abdomen until they hatch.1
Recognised by the official bits
- Taxonomy (via Wikipedia)
- Described by Latreille (in Milbert) in 1812; one of about eight living species in the genus Lybia (family Xanthidae).1
- Taxonomy (via Wikipedia)
- Genus Lybia currently holds eight extant species; two former members were moved to Tunebia.3
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Pom Pom Crab. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingDepends on species, many feed from the light and the watervaries
- Salinity checkevery week
- Water testevery week
- Top-upTop up evaporation with fresh RO water, not salt waterevery day
- Water changeAbout 10 to 20% of the waterevery 2 weeks
- Light checkevery month
Like what we are building? Buy Archy a bone.
All of this is free for everyone, with a source on every fact, and it will never show annoying ads. It was a big job to build, so if it helped you, buy Archy a bone. Any amount is lovely, and no is a perfectly fine answer too.
Archy is our Australian Cattle Dog and chief taste tester. Tips go to 4V3D OÜ, the small family studio behind Furry Diary.
Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.
- Lybia tessellata (Wikipedia) en.wikipedia.orgused for names, range, size, pattern, behaviour, diet, taxonomy
- Pom Pom Crab, LiveAquaria liveaquaria.comused for care level, water parameters, diet, temperament, colour
- Lybia (crab) (Wikipedia) en.wikipedia.orgused for anemone splitting, name origins, species count, research history
Checked 2026-09-30. Text is written in our own words from these sources.