Animals and protists
Because in the deep sea there is photosynthesis due to lack of light, also at deep-sea hydrothermal vents there are no plants. There are, however, animals and unicellular protists found at vents. There are not many species but those that manage to live there occur in very high numbers. Many are highly specialized. They do not only withstand the temperature fluctuations, but also dispose of the toxic hydrogen sulfide in various ways.
In 2006, we published together with our French colleagues Daniel Desbruyeres and Michel Segonzac, a book on the hydrothermal vent fauna. At that time approximately 550 animal species living at hydrothermal vents have been discovered. In the meantime, many more species were described. Because the hydrothermal vent book was sold out quickly you can download it now under this link www.zobodat.at/publikation_volumes.php
Desbruyeres D., Segonzac M., Bright M. 2006. Handbook of Deep-Sea Hydrothermal Vent Fauna. 2nd edition. Denisia 18, Landesmuseum Linz, Austria pp. 554.
Many fascinating animals inhabit the 9°50' N Volcano on the Pacific fire ring. Here are some animals from this volcano. All these pictures: Monika Bright (except when otherwise stated).
Snails and limpets (Phylum Mollusca, class Bivalvia)
Crustaceans (phylum Arthropoda)
Worms of the phylum Nemertea and bristle worms (phylum Annelida, class polychaeta)
The fish Thermarces cerberus, called eelpout and its little babies. Photograph (by P. Briand © Ifremer. in Handbook of Deep-Sea Hydrothermal Vents 2006)
The small animals and protists, belonging to the meiofauna: round worms (phylum Nematoda) less then 1 millimeter long, Copepoda (Phylum Arthropoda, subphylum Crustacea), small tubeworm like protists (phylum Ciliophora), forams with shells (phylum Foraminifera), all only visible under a dissection microscope