Pom Pom Crab
From Microcosm Aquarium Explorer
Note live anemone held by each pincer. Scott W. Michael
Overview
In a fascinating case of symbiosis, this crab holds small Crab Claw Anemones (Triactis producta or Bunodeopsis sp.) in its claws and waves them at a potential threat as if it is boxing. These tiny anemones reportedly have potent stinging abilities.
It may also use its “pom poms” to collect detritus, which it then feeds on. (The anemones benefit from being waved in the water column when food is passing by.)
This crab is attractively marked, with striped legs and bold markings on its carapace. The anemones are dropped during molting but are retrieved once this process is complete.
Curiously, lab studies have shown that a crab that loses one anemone will attempt to split the one it has into two regenerated clones, a method used by humans to propagate larger anemones.
They may be kept in groups and females will produce reddish colored egg masses that they carry on their abdomens. The pelagic larvae are called zoea.
Family: Xanthidae
Other common name(s):
- Boxer Crab
- Tesselated Anemone-Crab
- Mosaic Anemone-Crab
Native range:
Habitat: Coral reefs. Needs rocky caves and crevices for hiding. New specimens will hide until they feel secure, and may only emerge at night or in dim lighting if threatening predators are present.
Maximum length: 1.5 cm (1 in)
Minimum aquarium size: 8 L (2 gal)
Water: Marine 24 °C (75 °F) - 28 °C (82 °F)
General swimming level: Bottom.
Feeding
Omnivore. Will feed on detritus and small food particles that it picks off the substrate or that adhere to its anemone partner. Should attempt to target feed with finely chopped, meaty foods. Without sufficient food, the anemones may not survive.
Aquarium Compatibility
An ideal invertebrate for a nano tank. It is reef safe, but in a larger aquarium it is likely to disappear.
Prone to being eaten by a number of carnivorous fish species, but some may be deterred by its stinging anemones. Large dottybacks, hawkfishes, wrasses, sand perches, and puffers may attack them. Hermit crabs may harass Pom Pom Crabs.
It will not harm any of its tankmates.
Special Care
A cryptic species that must be provided with rubble, rocks, and crevices to hide under or in. If well cared for, it will live for several years in captivity.
Breeding/Propagation
May produce eggs in captivity. Larvae are called noea, but seldom survive in aquaria. Home aquarists are experimenting with feeding protocols to raise the hatches. See MOFIB.
Notes
There are at least two species sold as Pom Pom Crabs that enter the trade: this species, Lybia tesselata, (Indo-Pacific) and L. edmondsoni, (Hawaiian Islands). See: Hawaiian Pom Pom Crab.