David Wolfenden gives his advice to a reader who is thinking about adding a squat lobster to his tank.
Q) I have a reef tank which holds approximately 120 l. It has been set up for almost a year and contains live rock, various frags and polyps. I have a Strawberry gramma and a Clown goby and they are the only two fish, although I do have hermits and snails. I recently saw a tiny squat lobster offered for sale. I haven’t seen one of them before and I wondered if one would make a good inhabitant for this tank? Please could you advise and tell me anything about it such as feeding? Is it a scavenger in the same way as hermits are?
JONATHAN BAXTER, VIA EMAIL
A) DAVE WOLFENDEN SAYS: Squat lobsters look quite formidable for their size, with their impressive pincers. However, although a handful of squat lobsters are predatory, in most species the pincers are used primarily for defense and courtship.
Some species of squat lobster are tiny and cryptic — so much so you might never see them — and may hitchhike into the aquarium on live rock, where they perform useful janitorial functions. But one species in particular is sometimes seen in the trade as a decorative specimen: the Feather star or Crinoid squat lobster, Allogalathea elegans. Measuring barely more than a 2cm in length, these tiny crustaceans are found throughout the Indo-Pacific, where they live in close association with feather stars, usually in pairs. While feather stars themselves are exceptionally demanding, the squat lobsters themselves are not. They can be kept without a host as they will happily accept a variety of meaty foods as well as scavenging on leftovers. In fact they should only be kept with a host if you’re able to meet the exacting requirements of feather stars, which is not an easy challenge by any means.
This is a very attractive species, with distinctive stripes running along the length of the body and highly variable coloration, presumably relating to the colour of the animal’s host. This squat lobster is to all intents and purposes reef-safe and will make for a niftily unusual member of the clean-up crew. Do be warned that they can be territorial and will often fight to the death unless they’re in an established heterosexual pair; if you can get a pair, this is the way to go, otherwise keep only one specimen.