''Lamellibrachia luymesi'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

of tube worms in the family

Siboglinidae Siboglinidae is a family of polychaete annelid worms whose members made up the former phyla Pogonophora and Vestimentifera (the giant tube worms). The family is composed of about 100 species of vermiform creatures which live in thin tubes buried ...

. 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

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

l symbionts for its nutrition. These are located in a centrally located "trophosome".

''Lamellibrachia luymesi'' provides the bacteria with

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The under ...

and

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...

by taking them up from the environment and binding them to a specialized

hemoglobin Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythroc ...

molecule. Unlike the tube worms ''

Riftia pachyptila ''Riftia pachyptila'', commonly known as the giant tube worm and less commonly known as the Giant beardworm, is a marine invertebrate in the phylum Annelida (formerly grouped in phylum Pogonophora and Vestimentifera) related to tube worms ...

'' that live at

hydrothermal vent A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspo ...

s, ''L. luymesi'' uses a posterior extension of its body called the root to take up hydrogen sulfide from the seep sediments. ''L. luymesi'' may also help fuel the generation of sulfide by excreting

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

through their roots into the sediments below the aggregations. To support the carbon fixation they need for maintenance and growth, ''L. luymesi'' needs to extract sulfide, oxygen, and inorganic carbon from its environment and supply them to its symbionts in the trophosome via the vascular system. It also needs to ensure that no build up of the sulfate and hydrogen ion waste products occurs, which would inhibit the bacterial activity. Laboratory experiments have shown that although some of the waste products diffuse into the water column, about 85% of the sulfate produced and about 67% of the hydrogen ions are eliminated across the roots. 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 over 3 m (10 ft), and grows very slowly, and its

longevity The word " longevity" is sometimes used as a synonym for " life expectancy" in demography. However, the term ''longevity'' is sometimes meant to refer only to especially long-lived members of a population, whereas ''life expectancy'' is always ...

is over 250 years. It forms biogenic habitat by creating large aggregations of hundreds to thousands of individuals. Hydrogen sulfide can be lethal for many marine organisms, and the tubeworms help minimise the sulfide levels and maintain a stable habitat. Living in these aggregations are over 100 different species of animals, including

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, w ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is est ...

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throu ...

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

a, and

chordate A chordate () is an animal of the phylum Chordata (). All chordates possess, at some point during their larval or adult stages, five synapomorphies, or primary physical characteristics, that distinguish them from all the other taxa. These fi ...

s, many of which are found only at these seeps.

References

This article incorporates a CC-BY-2.5 from references.Boetius A. (2005). "Microfauna–Macrofauna Interaction in the Seafloor: Lessons from the Tubeworm". '' PLoS Biology'' 3(3): e102. Cordes E. E., Arthur M. A., Shea K., Arvidson R. S. & Fisher C. R. (2005). "Modeling the Mutualistic Interactions between Tubeworms and Microbial Consortia". '' PLoS Biology'' 3(3): e77. {{Taxonbar, from=Q2922848 Sabellida Animals described in 1975