The name alludes to how the worms bore into the bones of whale carcasses to reach enclosed lipids, on which they rely for sustenance.
The worms were found living on the bones of a decaying gray whale in the Monterey Canyon, at a depth of 2,893 m (9,491 ft).
[5] Osedax rely on symbiotic species of bacteria that aid in the digestion of whale proteins and lipids and release nutrients that the worms can absorb.
[6] Osedax have colorful feathery plumes that also act as gills and unusual root-like structures that absorb nutrients.
This sheath could also play an important role in reducing the damage to Osedax skin by absorbing harmful acid.
Between 50 and 100 microscopic dwarf males live inside the tube surrounding a single female and never develop past the larval stage; they produce sperm from yolk reserves.
Male Osedax are microscopic dwarfs that live as "harems" inside the lumen of the gelatinous tube that surrounds each female.
[1] In late 2005, an experiment by Swedish marine biologists resulted in the discovery of a species of the worm in the North Sea off the west coast of Sweden.
In the experiment, a minke whale carcass that had been washed ashore had been sunk to a depth of 120 m (390 ft) and monitored for several months.
Biologists were surprised to find that, unlike the previous discoveries, the new species, colloquially known as "bone-eating snot flower" after its scientific name (Osedax mucofloris), lived in relatively shallow waters.
In November 2009, researchers reported finding as many as 15 species of boneworms living in Monterey Bay on the California coast.
[17] Annelid sex is typically determined by genetic factors,[18] however models of environmental sex determination have been proposed for Osedax, in which larvae that settle on bones mature into females, while larvae that settle on female Osedax do not fully develop and mature into males.
[25] Collagen is degraded using a family of endopeptidases called matrix metalloproteinases (MMPs), which facilitates nutrient absorption by the Osedax.
[25] This function is complemented by the Oceanospirillales symbionts, which utilize the glyoxylate cycle to catabolize nutrients from whale bones and convert fatty acids into carbohydrates.
[33] Osedax have also been observed colonizing terrestrial mammal bones mixed in with galley waste from a surface vessel.
Burrows closely similar to those made by Osedax species have been found in the bones of ancient marine birds and plesiosaurs, suggesting that the genus may once have had a wider range of foods.
The downside of the deterioration caused by Osedax is that it speeds up the process of erosion, therefore only allowing this new fauna their new habitats for a temporary period.
[38] The oldest trace fossils on bones characteristic of Osedax are from a plesiosaur humerus from the Cambridge Greensand, England, likely reworked from late Albian (c. 100 million years old) sediments and a rib and costal plate from a sea turtle found in Cenomanian (100–93 million years ago) aged sediments of the Chalk Group, England.
[34] Following the extinction of almost all large marine reptiles at the end of the Cretaceous, Osedax likely persisted on the bones of sea turtles and fish.
[40] In terms of evolutionary history research, the Osedax could have had negative impact in preserving fossil record because its appearance at the shelf-depth combined with its ability to efficiently break down marine vertebrates skeletons.