Hydrothermal Vents are oceanic hot springs in volcanically active areas; they are mostly deep and along the midocean ridges (but sometimes are shallow, e.g., near Iceland or volcanic islands in the Mediterranean). At these vents, hot (up to 400C) mineral-laden water provides abundant energy, mostly as H2S (rotten-egg-smelling hydrogen sulfide). Eubacteria and archaea use H2S for energy, forming the basis of the food chain. Similar clams, mussels and tubeworms with symbionts are found here. The microbes use a process called chemosynthesis (see ONR site for more information). Limpets, snails and other worms graze on microbial mats and filaments. Fish, octopods and crabs are carnivores and scavengers.
On the Juan de Fuca ridge, the main animal with symbionts is Ridgeia piscesae, a vestimentiferan tubeworm related to the more famous Riftia of the East Pacific Rise. Ridgeia is unusual in that it comes in several forms that look like distinct species. In warm, high-sulfide sites it grows into the so-called Short-Fat (SF) form, with a grey or white tube with the consistency of parchment; however at cool, low-sulfide sites it grows a Long-Skinny (LS) tube, up to a meter long and with a more rigid but brittle consistency. Intermediate forms can be found under other temperature-sulfide conditions.

A. JUAN de FUCA Ridge--Endeavour Segment: our 2007 & 2008 expeditions led by Dr. Ray Lee (Wash. State Univ.) with the ALVIN aboard the R/V Atlantis

LINKS: NOAA map of the Ridge

Mothra/Faulty Towers

Main Endeavour; Clambed

Middle Valley

Endeavour Rift Valley floor

Animals Collected

•MOTHRA/FAULTY TOWERS site, Juan de Fuca Ridge; 2.3km deep (click here for paper with fantastic mosaic image of Faulty Towers)

ABOVE: Chimneys/smokers at Faulty Towers (with names like Roane, Giraffe, etc). Note that ROANE (5th image, top) was decapitated by UW in 1998 for analysis of microbial life (it is now on display in the Amer. Museum of Natl. history).
		RIGHT: more towers
FAR ABOVE: a smoker chimney being collected with Alvin claw; JUST ABOVE: the chimney on the ship, broken open to reveal lining of IRON PYRITE (Fool's Gold) crystals		ABOVE: Black and white smokers
Vent snails B. thermophilus		Unidentified jelly!	Crab on tower	Snails on tower	P. sulfincola; Ridgeia	Ridgeia close-up	Ridgeia "bush"

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•MAIN ENDEAVOUR Site of the Ridge; 2.2 km deep; HULK and DANTE edifices; also CLAMBED site north of Main

White and black smoker chimneys, some with tubeworms (most at DANTE formation)
Alvin sampling black smoker water	HULK formation	More smoker formations (Dante)

Carb, orange mat, tubeworms	Ridgeia tubeworm colonies; rightmost one is of long-skinny form at CLAMBED vent site					Fish with vent snails	Paralvinella palmiformis

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•MIDDLE VALLEY region just off the Juan de Fuca Ridge; 2.4 km deep

White smoker chimneys				Sulfide SEEP with unnamed species of Vesicomyid clams (see close-up of clam in ANIMALS section below)

Bathyraja skate	Ridgeia tubeworm 'bush'	Venus flytrap anemone	Graneledone octopod near Middle Valley site		Unidentified cucumbers in Middle Valley

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•RIFT VALLEY seafloor

Lava formations on the Juan de Fuca rift valley floor (Endeavour segment)

Animals seen on the rift valley floor (coral, fishes, skate eggcases, octopods)

•ANIMALS brought back to the ship from the Juan de Fuca ridge, on ALVIN:

Paralvinella worms in vent chimneys		Ridgeia, LS (long-skinny) form	Ridgeia, the SF (short-fat) form; shown dissected in the 2 righthand images
Paralvinella palmiformis		Paralvinella sulfincola	Scale worms in Ray Lee's pressure chamber	Scale worms (covered with bacterial filaments, right)
Maldonid (bamboo) worm		Limpet Lepidodrilus	Limpet ?	Juan de Fuca vent mussel? A rare specimen	Unnamed species of Vesicomyid clam from Middle Valley seeps		Anemone near Middle Valley seeps

Pycnogonid (male carrying eggs; right)		B. thermophilus vent snail with limpet	Graneledone octopod from Middle Valley		Galatheid crab from Middle Valley		Vent ciliate! (single-celled protozoa that form tubes to make a blue mat)

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B. Mediterranean Sea; Mid-Atlantic Ridge; East Pacific Rise

A shallow hydrothermal vent off Vulcano, an Italian island in the Mediterranean. Note the sulfur deposits. For the deeper vents on the mid-ocean ridges, see: ONR site for animations, pictures, detailed information.	Bathymodiolus mussel from the Mid-Atlantic Ridge (provided by Cindy Van Dover). These have bacterial symbionts in their gills.	Rimicaris shrimp from the Mid-Atlantic Ridge (provided by Cindy Van Dover). These unique animals swim in and out of hot vents, have no eyestalks, but have unique eyepatches on their backs. Dr. Van Dover hypothesizes that these sense faint light (either infrared or from chemiluminescent reactions) from the vents.	The most "famous" animals of the hydrothermal vents are the giant Riftia tubeworms (vestimentiferans; Siboglinid family of polychaetes). They are up to 2 m (6 feet) long! They have no guts, and live off their symbionts (see SEEP TUBEWORM for more on this process). For better pictures and a video, see U. Delaware Tubeworm site and Peter Batson's photos below.

C. PETER BATSON'S PHOTOS

BELOW are copyrighted photos courtesy of PETER BATSON, author of Deep New Zealand - Blue Water, Black Abyss. Please contact him for permission at his website, ExploreTheAbyss. See MIDWATER page for more of his photos.
Alvinella, a polychaete tubeworm that may be able to live in water of 50C or higher.	Tevnia, a small vestimentiferan tubeworm often found with Riftia.	A plume of Riftia (see description of these tubeworms under my photo, above right)	A Riftia body out of its tube	Brittle stars, limpets at a vent	Thermarces fish at a vent	Munidopsis galatheid crab	Bythograea crab at a vent

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HOME PAGE: CONTENTS, ZONES

1. Bacteria, UNKNOWNS, WORMS

2. BATHYAL and ABYSSAL FISHES

3. ECHINODERMS

4. CNIDARIA, Porifera

5. MOLLUSCS, CRUSTACEA, PYCNOGONIDA

6. MIDWATER (MESOPELAGIC)

7. SURFACE (EPIPELAGIC)