Ryan Photographic - Galatheidae - Squat lobsters
Family Galatheidae
There are currently 240 species of galatheids distributed in 12 genera (World Register of Marine Species) or 18 genera (Wikipedia). They are called squat lobsters because they look a little like lobsters, although they are more closely related to hermit crabs. The term "squat lobster" is also used for animals in the family Muninidae. Several genera previously included in the Galatheidae have been moved to the Muninidae.
Our knowledge of the galatheids is still somewhat limited and the existence of "species complexes" may vastly increase the reported diversity. In 2011, a molecular study combined with traditional taxonomy revealed that the elegant squat lobster, Allogalathea elegans, was in fact FOUR species. The genetic evidence was unequivocal and, in possession of this, the authors were able to find morphometric differences that allow identification without genetic analysis. My identification of A. elegans and A. babai are therefore tentative. If my A. babai identification is correct then it represents a new record for Fiji.
The squat lobsters I have photographed have all been commensal with some other invertebrate. They have wide-ranging hosts including sponges, crinoids and soft corals. Others live freely in holes and crevices.
Allogalathea babai Baba's crinoid squat lobster

Allogalathea babai Baba's crinoid squat lobster, Fiji
Allogalathea elegans Elegant crinoid squat lobster

Allogalathea elegans Elegant crinoid squat lobster, Fiji
Galathea Squat lobster

Galathea species, Kri Eco, Raja Ampat IMG_7812
Lauriea siagiani Hairy squat lobster

Lauriea siagiani Hairy squat lobster, Kri Eco, Raja Ampat IMG_7727

Lauriea siagiani Hairy squat lobster, Magic Bay Rao, Morotai, Indonesia 5P7A7290