Anemones, tube anemones, corallimorphs and zoanthids. Hosts as often as hazards, and several of them are worth searching for what is living in them.
A Haddon's carpet anemone has a household living in it - anemonefish, porcelain crabs and commensal shrimps - and a tube anemone usually has a crab or a shrimp on the column. Searching an anemone is a more reliable way to add species than searching the sand around it.
Two sting hard enough to matter. The hell's fire anemone raises welts that last, and it is on rubble at a depth where a hand is often put down. Zoanthids in the genus Palythoa carry palytoxin, which is a problem for people who keep them in aquariums rather than for divers who leave them alone.
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 12 carry a record at each destination. A species usually carries several, so these do not add up to 12.
All 1316 species in one index, with filters for destination, rarity and hazard.
