Less a group of animals than a group of structures. Almost everything else in the index sits on, in or beside one of these, and a diver who can name the host can usually find the animal.
The hosts divide by what they hold. The gorgonians, black corals and whip corals are the vertical structure on a slope and hold pygmy seahorses, whip coral shrimps, gobies and the xeno crab. The sponges hold their own set - hairy squat lobsters in the folds of a barrel sponge, shrimps and gobies in the tubes, and a barrel sponge grazed over by hundreds of small synaptid sea cucumbers.
The reef-building corals are here in outline rather than in detail. Acropora builds most of the reef and is the first to go when the water warms; the mushroom corals lie loose on sand, can right themselves and move short distances; the pulsing Xenia colonies open and close continuously and nobody has settled why. One entry is not a coral at all: fire coral is a hydrozoan, and it is the commonest sting on a reef because it looks like one.
Every one has a page. They are shown as a list rather than as pictures because nothing has been photographed or logged for them yet, and a species with nothing behind it should not sit in front of one that has.
How many of the 29 carry a record at each destination. A species usually carries several, so these do not add up to 29.
All 1316 species in one index, with filters for destination, rarity and hazard.
