Host-related Morphological Variation of Dwellings Inhabited by the Crab Domecia acanthophora in the Corals Acropora palmata and Millepora complanata (Southern Caribbean)

Brachyuran crabs of various families are known as obligate associates of stony corals, with many of these species living as endosymbionts inside the skeleton of their hosts. In particular, coral gall crabs (Cryptochiridae) have been well studied in tropical coral reefs around the world. These crabs can be recognized by the shape of their dwellings (or pits), which may be crescent-shaped or resemble a slit, a canopy, a basket, or a gall, depending on the identity and morphology of their host, and on the position inside the host’s skeleton. Cryptochirids are each known to be associated with a few scleractinian host species (Anthozoa: Scleractinia) or only one. Crabs of the species Latopilumnus tubicolus Türkay and Schuhmacher, 1985 (Pilumnidae), have so far only been reported as endosymbionts of the Indo-Pacific scleractinian Tubastraea micranthus (Ehrenberg, 1834). Their dwellings are unique because they start in one of the coral’s calyces from where they penetrate deep inside the coral branches, becoming long and tubular, whereas the pits (or cysts) of cryptochirids remain relatively shallow.

Article referenced in BioNews 34 article "New discoveries on relationships between host corals, crabs and christmas tree worms"