It is an extremophile found only at hydrothermal vents in the Pacific Ocean, discovered in the early 1980s off the Galápagos Islands by French marine biologists.
In 1980 Daniel Desbruyères and Lucien Laubier, just a few years after the discovery of the first hydrothermal vent system, identified one of the most heat-tolerant animals on Earth — Alvinella pompejana, the Pompeii worm.
In 1997, marine biologist Craig Cary and colleagues found the same worms in a new section of Pacific Ocean, near Costa Rica, also attached to hydrothermal vents.
Perhaps most fascinating, their tail ends are often resting in temperatures as high as 80 °C (176 °F), while their feather-like heads stick out of the tubes into water that is much cooler, 22 °C (72 °F).
[3] Scientists are attempting to understand how Pompeii worms can withstand such extreme temperatures by studying the bacteria that form a "fleece-like" covering on their backs.
Finally, surrounding the organs is a coelom filled with coelomocytes, a type of phagocyte that acts as an immune system for the animal.
This gives the blood access to a space very close to the skin of A. pompejana, thus allowing more effective oxygen diffusion.
Additionally, A. pompejana's gills have the highest specific surface area of any polychaete and small diffusion distances between the circulatory system and external seawater further assist in oxygenation.
Therefore, to allow adequate release of oxygen within the body, the Pompeii worm has acidic blood with a pH range of 6.6-6.9.
A lower pH decreases the energy required to unbind oxygen from haemoglobin by utilising the Bohr effect.
[8] Alvinella pompejana are a gonochoric species with distinct differences between the male and female genital pores (located at the base of the gills).
Prior to fertilisation these oocytes are flattened spheres with an undulating membrane and a slightly off centre germinal vesicle that is less dense than the surrounding cytoplasm.
[11] The method for transfer of spermatozoa it is likely achieved through pseudo-copulatory behaviour as the worms have been observed diving head-first into tubes in a display that may be mating.
Its family name Alvinellidae and genus name Alvinella both derive from DSV Alvin, the three-person submersible vehicle used during the discovery of hydrothermal vents and their fauna during the late 1970s.
The bacteria may possess special proteins, "eurythermal enzymes", providing the bacteria—and by extension the worms—protection from a wide range of temperatures.
[3] Studies are hampered by the difficulties of sampling; It is currently quite difficult for Pompeii worms to survive decompression.
The main nutrition for the Pompeii worm is derived from chemosynthetic bacteria, this is why it chooses to live in such intense environments.
This is due to the toxic metal levels of hydrothermal vent fluid, a factor chemosynthetic bacteria require.
[1] Study of the Pompeii worm's seemingly life-sustaining bacteria could lead to significant advances in the biochemical, pharmaceutical, textile, paper, and detergent industries.