But it turns out that Osedax worms are not the only animals that eat whale bones. In a recent paper in Biological Bulletin, MBARI researcher Shannon Johnson describes two new species of bone-eating snails. One of the new snails, Rubyspira osteovora, is the second most abundant animal (after Osedax worms) at the deepest Monterey whale fall.
Johnson and her colleagues are still trying to determine if these snails can digest whale bones directly or require the help of "symbiotic" bacteria. If Rubyspira snails do not require symbiotic bacteria to digest bone, they would be the only known marine animals capable of surviving on a diet of bone alone. They also appear to be "living fossils," representing a lineage that survived from the time of the dinosaurs (the Cretaceous era).
With all of these worms and snails feeding on them, whale carcasses in Monterey Canyon do not seem to last as long as those observed elsewhere. Lundsten's paper suggests that the whale carcasses in Monterey Canyon will completely decompose in less than 10 years.
In contrast, whale carcasses studied off Southern California may survive for 50 to 100 years. Lundsten and his coauthors suggest that the Southern California whale carcasses last longer because: 1) They lie in deep basins where the seawater contains very little oxygen (and thus fewer Osedax worms); and 2) They are mostly adult whales, which have thicker, more heavily calcified bones, whereas the whales in Monterey Bay were mostly juveniles.
Even though the whale carcasses that were "planted" in Monterey Canyon are rapidly disappearing, they continue to support interest
|Contact: Kim Fulton-Bennett|
Monterey Bay Aquarium Research Institute