polychaete Osedax japonicus and the bathymodiolid mussel Adipicola pacifica (Okutani et ai, 2003), both endemic to the bone surfaces, were also found on the same blocks of bones with P.
Discrete morphospecies of siboglinid
tubeworms from eastern Pacific vents were found on examination with molecular markers to be developmentally plastic ecophenotypes (Black et al.
2009) resulted in two hypothetical scenarios in which Osedax split from their siboglinid
relatives either 45 MYA (concurrent with the evolution of large cetaceans) or 135 MYA when large marine reptile carcasses could have provided suitable habitat.
Tyler & Young (1999) and Young (2003) reviewed the data, which mainly characterized the larger megafuana including siboglinid
and alvinellid polychaetes, bivalve molluscs, and Crustacea.
Endosymbioses between bacteria and deep-sea siboglinid
tubeworms from an Arctic Cold Seep (Haakon Mosby Mud Volcano, Barents Sea).
The dimensions of the trophosomes in the different siboglinid
taxa also reflect a high plasticity of this organ.
Most obviously, in many intracellular endosymbioses specific symbiont-housing organs have developed, such as the light organ in bobtail squids, the root nodules in legumes, the bacteriomes in insects, and the trophosome in siboglinid
Although no molecular studies have identified free-living siboglinid
symbionts thus far (Southward et al.
Osedax, a genus of bone-eating siboglinid
annelids, was first described from a whale carcass at 2893-m depth in Monterey Bay, California (Rouse et al.
Levels of interspecific COI divergence found between species of deep-sea bivalve molluscs, siboglinid
tubeworms, and decapod crustaceans typically exceed 4%, whereas intraspecific divergence is less than 2% (Peek et al.
The ingroup comprised four siboglinid
species representing one genus of frenulate and three genera of vestimentiferans, as shown in Table 1.
Using histology, we have examined the female reproductive system of five vestimentiferan siboglinid
species: Riftia pachyptila, Ridgeia piscesae, and Tevnia jerichonana from Pacific hydrothermal vents, and Lamellibrachia luymesi and Seepiophila jonesi from cold seeps in the Gulf of Mexico.