Summary

Riftia pachyptila is a highly successful animal that lives in an extreme environment, uninhabitable for most organisms due to associated environmental stressors experienced at hydrothermal vent sites.  Coping with pressure and a lack of light is a challenge for all deep sea organisms, hydrothermal vent fauna also live in an environment of temperature fluctuation, reduced oxygen, low pH and high concentrations of toxic hydrogen sulphide and heavy metals.

Since the discovery of tubeworms, studies have found that the anatomy of tubeworms is specialised in order to maximise the output of glutamine by symbionts by the process of chemosynthesis.  R.pachyptila has many highly vasculated lobes of tissue in trophosome which house symbionts in large magnitudes.  The large surface area of the plume allows rapid exchange of metabolites with the environment.  Large quantities of haemoglobin in the blood bind to oxygen and transport it around the body.  A separate, larger form of haemoglobin binds specifically to sulphide which detoxifies it while being transported to symbionts. Free swimming lecithotrophic larvae of R.pachyptila travel long distances to reach vent sites away from the parental habitat, this allows the species to live in ephemeral habitats.

Despite extensive study since their discovery, there is still a lot that is not known about the biology of R.pachyptila.  Due to the inaccessibility of hydrothermal vent sites, these habitats are difficult to sample.  Further exploration of the deep sea is needed in order to gain an understanding of species distribution. Work is also still yet to be done for a full understanding in methods of nitrogen uptake and life history of tubeworms. Discovery of fauna at sites such as hydrothermal vents indicate that life can be sustained in challenging deep water environments.  As the majority of the deep sea is yet to be explored, it is highly possible that other sites, providing energy sources for faunal assemblages are yet to be found.

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