The reproductive system of Osedax (Annelida, Siboglinidae): ovary structure, sperm ultrastructure, and fertilization mode

@article{Katz2013TheRS,
  title={The reproductive system of Osedax (Annelida, Siboglinidae): ovary structure, sperm ultrastructure, and fertilization mode},
  author={Sigrid Katz and Greg W. Rouse},
  journal={Invertebrate Biology},
  year={2013},
  volume={132},
  pages={368 - 385}
}
Osedax is a genus of siboglinid annelids in which the females live on dead vertebrate bones on the seafloor. These females have a posterior end that lies within the bone and contains the ovarian tissue, as well as the “roots” involved with bone degradation and nutrition. The males are microscopic and live as “harems” in the lumen of the gelatinous tube that surrounds the female trunk, well away from the ovary. Females are known to spawn fertilized primary oocytes, suggesting internal… 

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References

SHOWING 1-10 OF 67 REFERENCES
Spawning and development in Osedax boneworms (Siboglinidae, Annelida)
TLDR
The high fecundity and apparently continuous reproduction of Osedax boneworms permits the opportunistic exploitation of sunken vertebrate bones.
Postembryonic development of the bone-eating worm Osedax japonicus
TLDR
The postembryonic development and settlement of Osedax japonicus Fujikura et al. are reported, which shows that the recruitment of dwarf males was induced by rearing larvae with adult females, and females started to spawn eggs 6 weeks after settlement.
Internal fertilization in the salp Thalia democratica
TLDR
To determine if the pattern of internal fertilization of P. socia is generally applicable to salps, an ultrastructural study on blastozooids of Thalia democratica is performed.
Sperm Storage, Internal Fertilization, and Embryonic Dispersal in Vent and Seep Tubeworms (Polychaeta: Siboglinidae: Vestimentifera)
TLDR
It is shown experimentally that most eggs are inseminated internally, that fertilization rate is typically lower than 100%, that meiosis is completed after eggs are released from the female, and that the dispersal phase includes the entire embryonic period.
The simplicity of males: Dwarf males of four species of Osedax (Siboglinidae; Annelida) investigated by confocal laser scanning microscopy
TLDR
The similarity of Osedax males to the larvae ofOsedax and other siboglinid annelids as well as similarities shown here to the neuromuscular organization seen in other annelid larvae supports the hypothesis of paedomorphosis in males of Osingax.
Morphology of Gametes and Insemination in the Vestimentiferan Riftia pachyptila
Ultrastructure of gametes (sperm and eggs) of vestimentiferan tubeworms and external-internal insemination by means of spermatozeugmata in Riftia pachyptila were described. The spermatozoa of Riftia
Spawning and Development in Osedax Boneworms
TLDR
Cytological and molecular analysis of the spawned oocytes of two Osedax species revealed no evidence for the bacterial endosymbionts that the female worms require for their nutrition, suggesting that the bacteria must be acquired later from the environment, as in other siboglinids.
Sperm masses and sperm transfer in a vestimentiferan, Ridgeia piscesae Jones, 1985 (Pogonophora: Obturata)
Discrete sperm masses, of irregular outline, 2–5 mm in their maximum dimension, were found on males and females of Ridgeia piscesae Jones, 1985 (Pogonophora: Obturata), hydrothermal vent tube worms
Acquisition of Dwarf Male “Harems” by Recently Settled Females of Osedax roseus n. sp. (Siboglinidae; Annelida)
TLDR
A time-series analysis revealed the presence of a new species of Osedax, a genus of bone-eating siboglinid annelids, which is the fifth species described since the erection of this genus and, like its congeners, uses a ramifying network of “roots” to house symbiotic bacteria.
A New Species of Osedax (Annelida: Siboglinidae) Associated with Whale Carcasses off Kyushu, Japan
TLDR
A new whale-bone-eating polychaete species of the genus Osedax was found on sperm whale carcasses submerged off Cape Nomamisaki, Kyushu, Japan, at a depth of approximately 200 m and is the first species from the western Pacific.
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