Siboglinidae

They can also be found in association with hydrothermal vents, methane seeps, sunken plant material, and whale carcasses. The first specimen was dredged from the waters of Indonesia in 1900. These specimens were given to French zoologist Maurice Caullery who studied them for nearly 50 years. Most siboglinids are less than 1 millimetre (0.04 in) in diameter, but some species grow up to 10–75 centimetres (3.9–29.5 in) in length. They inhabit tubular structures composed of chitin which are fixed to rocks or other substrates. The tubes are often clustered together in large colonies. The body cavity has a separate compartment in each of the first three regions of the body and extends into the tentacles. The opisthosoma has a coelomic chamber in each of its 5 to 23 segments, separated by septa.