The 27 Best Deep-Sea Species #14: Alviniconcha, the Hairy Vent Snail

Photo on left courtesy of C.Fisher/Ridge2000. Photo on the right from Linda Zelnio.

#14 Alviniconcha hessleri (Phylum: Mollusca, Class: Gastropoda, Order: Sorbeoconcha, Family: Provannidae)

Hairy things aren’t just for ye landlubbers. The deep-sea is home to several hairy critters including the hairy vent snail, Alviniconcha. The hairy appearance are actually spines protruding from the periostracum, a thin organic layer that coats the mineralized shell of a snail. Alviniconcha‘s shell is very thin. It is this biologist’s opinion that the spines might help keep off fouling creatures, such as drilling limpets. But no one knows for sure quite yet.

Alviniconcha also has blue blood due the respiratory pigment hemocyanin and carries very enlarged gills. My measurements indicate that the dry weight of the gills can get up to 21% of the total dry mass (excluding shell). For comparison, the average intertidal intertidal snail has 4-7% of its total body weight devoted to the gills. This makes sense since Alviniconcha has a very reduced stomach and digestive tract. It gets most, if not all, of it’s nutrition from chemoautotrophic bacteria housed in its gills. "Chemoautotrophic" means that the bacteria oxidize hydrogen sulfide as an energy source, normally a toxic chemical to most animal life. But these extreme snails can bring in the goods for their bacterial helpers and thrive en masse.

Want to know more about this hairy little friend? I wrote a detailed article on this snail for Deep Sea News over a year ago. -KAZ

• #27: Brachiopods
• #26: Pig Butt Worm
• #25: Crawling Crinoids
• #24: Tube Worms
• #23: Dumbo Octopus
• #22: Xenophyophores
• #21: Phronima
• #20: Swimming Sea Cucumbers
• #19: Black Devil Anglerfish
• #18: Venus Fly-trap Anemone
• #17: Tripod fish, Bathypterois
• #16: Chaunax, the red-eyed gaper
• #15: Spookfish, Rhinochimaera pacifica