Allogalathea elegans – Crinoid Squat Lobster
Allogalathea elegans (known as the feather star squat lobster, crinoid squat lobster or elegant squat lobster) is a species of squat lobster that is sometimes kept in marine aquariums. This species was first described in 1848 by Adams and White.
- Galathea deflexifrons Haswell, 1882
- Galathea elegans Adams & White, 1848
- Galathea grandirostris Stimpson, 1858
- Galathea longirostris Dana, 1852
- Galathea longirostris Yokoya, 1936
The cephalothorax of Allogalathea elegans is droplet-shaped. The extremity of the body corresponds to the triangular rostrum of the animal, which are positioned on each side the pedunculated eyes. The chelipeds or the first pair of legs are endowed with pincers and are longer than the animal body. The last pair of legs are wasted. The body and mainly the legs are covered with small hairs. The animal’s size depends on the sex. Females are usually bigger than males but never grow over 2 cm. The animal’s coloration is variable and is matching the colours of its host but not systematically. It can be uniform and varied from dark red, blackish purple, orange or brown. But generally, the observed animals have longitudinal stripes which the thicknes, the number and the tint varies.
Allogalathea elegans lives in the tropical waters of the Indo-Pacific area, Red Sea included.
Allogalathea elegans is a commensal species living in association with crinoids in which it gets protection and an ideal support for its feeding. They are capable of living outside its host, but its life expectancy will be shorter because it will not be shielded from predators.
Allogalathea elegans feeds off plankton while taking advantage of its host who has the same diet and who always positions in the best catchment areas for the plankton to feed.
Allogalathea elegans lives in couple on their host. The observation is not always easy because or the animal exposes itself in the crinoid’s arms when both are feeding, or it hides at the level of the claws foot of his host.
In an aquarium, Allogalathea elegans requires a water temperature of 77–79 °F (25–26 °C), a pH of 8.1–8.3 and a salinity of 1.020–1.024. Small crevices in rocks act as hiding places for this shy crustacean. Allogalathea elegans prefers thawed food but will also eat small freeze dried items.