Hydrothermal Vents: Megafauna (Akanshu and Sara)

Figure 1 (Above): A typical hydrothermal vent.

A hydrothermal vent is, “a fissure in the ocean floor especially at or near a mid-ocean ridge from which mineral-rich superheated water issues” (4). Despite the lack of sunlight for photosynthesis, there is a rich faunal diversity near these vents. Archaebacteria which perform chemosynthesis, the conversion of chemicals into usable energy, are the base of the food chain (1). Some scientists believe that biochemistry may have originated at these vents (8). Animals here often exhibit deep-sea gigantism; a tendency for animals to become enormous, including the giant tube worm (2). To read more details about hydrothermal vents, click here.

Figure 2 (Right): Crysomallon squamiferum — the scaly-foot gastropod— is a hydrothermal vent snail that displays a unique tri-layered shell composed of iron sulfide. It captures floating iron sulfide in the water to incorporate it into its shell. This thick, protective shell serves as a defense mechanism against predators that inject venom to kill their prey (7). Scientists and engineers are studying the properties of this shell to develop better military armor (3). Click here to read more about how this iron-plated snail has inspired new armor design.

Figure 3 (Above): Located in the Pacific Ocean, Riftia pachyptila — the giant tube worm — is the fastest growing marine invertebrate, growing over 33 inches a year lengthwise. These organisms symbiotically depend on chemosynthetic bacteria as their energy source. Shrimp and crabs often nibble at these worms  (5).


Video 1 (Below): Rimicaris exoculata (The Vent Shrimp).
Rimicaris exoculata — the vent shrimp—does not possess eyes yet exhibits a high concentration of rhodopsin (a visual pigment). These “eyespots” appear as shiny pink regions (6).

Figure 4 (Above): A microscopic hydrothermal worm.

Video 2 (Above): The NOAA ship Okeanos Explorer discovers a new vent at the Galápagos Rift.

To learn more about recently discovered species from hydrothermal vents found near Antarctica, click here.

References Cited:

1.  MacInnis, Joseph. James Cameron’s Aliens of the Deep. Washington, D.C.: National Geographic Society, 2004. 
2.  "The Deep Sea." MarineBio. Accessed April 2, 2012. http://marinebio.org/oceans/deep/. 
3.   McClain, Craig. “Fool’s Gold from Hydrothermal Vents to Plankton.” Deep Sea News. Last modified  May 15, 2011. http://deepseanews.com/‌/‌/ls-gold-from-hydrothermal-vents-to-plankton/‌.    
4.  Merriam-Webster Online, s.v. "hydrothermal vent," accessed April 2, 2012, http://www.merriam-webster.com/dictionary/hydrothermal%20vents.      
5. Stover, Dawn. “Creatures of the Thermal Vents.” Ocean Planet Smithsonian. Accessed April 2, 2012. http://seawifs.gsfc.nasa.gov/_PLANET//_vents.html. 
6. Zelnio, Kevin. “The ‘Eye’ of the Vent Shrimp.” Deep Sea News. Last modified  April 1, 2010. http://deepseanews.com/‌/‌/eye-of-the-vent-shrimp/‌. 
7. Clive Thompson, "Molecular Secrets of The ‘Iron-Plated Snail’,"  Collision Detection (blog), February 2, 2010, http://www.collisiondetection.net/mt/archives/2010/02/life_isnt_easy.php.
8. Martin, William, and Michael J. Russell. "On the Origin of Biochemistry at an Alkaline Hydrothermal Vent." Philosophical Transactions of The Royal Society 362, no. 1486 (October 2007): 1887-1926. doi:10.1098/ rstb.2006.1881.