Lamellibrachia

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Lamellibrachia

Lamellibrachia luymesi

Kingdom:	Animalia
Phylum:	Annelida
Class:	Polychaeta
Order:	Sabellidae
Family:	Siboglinidae
Genus:	Lamellibrachia Webb, 1969

Species

See text

Lamellibrachia is a genus of tube worms related to the giant tube worm, Riftia pachyptila. It lives at deep-sea cold seeps where hydrocarbons (oil and methane) are leaking out of the seafloor. It is entirely reliant on internal, sulfide-oxidizing bacterial symbionts for its nutrition.

L. luymesi provides the bacteria with hydrogen sulfide and oxygen by taking them up from the environment and binding them to a specialized hemoglobin molecule. Unlike the tube worms that live at hydrothermal vents, Lamellibrachia uses a posterior extension of its body called the root to take up hydrogen sulfide from the seep sediments. Lamellibrachia may also help fuel the generation of sulfide by excreting sulfate through their roots into the sediments below the aggregations [1].

The most well-known seeps where L. luymesi lives are in the northern Gulf of Mexico from 500 to 800 m depth. This tube worm can reach lengths of over 3 m (10 ft), grows very slowly, and may hold the longevity record for an invertebrate with individuals living to be over 250 years old. It forms biogenic habitat by creating large aggregations of hundreds to thousands of individuals. Living in these aggregations are over a hundred different species of animals, many of which are found only at these seeps.

While most species of vestimentiferan tubeworms live in deep waters below the photic zone, Lamellibrachia satsuma was discovered in Satsuma Bay, Kagoshima at a depth of only 82 m, the shallowest depth record for a vestimentiferan.

[edit] Species

Lamellibrachia barhami Webb, 1969
Lamellibrachia columna
Lamellibrachia juni
Lamellibrachia luymesi van der Land and Nørrevang, 1975 - Gulf of Mexico seep tubeworm
Lamellibrachia satsuma Miura, Tsukahara & Hashimoto