Frenulata

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Frenulata
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Annelida
Clade: Pleistoannelida
Clade: Sedentaria
Order: Sabellida
Family: Siboglinidae
Clade: Frenulata

Frenulata, "beard worms", is a clade of Siboglinidae, "tube worms". They are one of four lineages with numerous species. [1] [2] They may be the most basal clade in the family. [3] Despite being the first tube worms to be encountered and described, they remain the least studied group. This is because of their slender shape, they often get destroyed as a result of being caught as bycatch or poor preservation. They are found primarily in deep, muddy sediments, cold seeps, and anoxic firth sediments. [4] [5]

Contents

Anatomy

Frenulata are typically long and slender, they have been described as "thread-like". [5] They typically range from 0.1–3 mm in diameter. [6] Like other Siboglinidae, they have distinct segments: a plume, a vestimentum, and a trophosome. The vestimentum is used to retract the organism in and out of its tube. The trophosome is unique to tube worms. It was found to house bacterial symbiotes in Riftia. [7] Like other tube worms, they lack a digestive tract. [8] In order to survive, it holds endosymbiotic bacteria that supply the worm with nutrients. The bacteria nourishes the worm by oxidizing sulfur from its surrounding environment, with one methanotrophic exception being Siboglinum poseidoni. [5] The inorganic compounds are delivered to the trophosome by both the vascular and coelomic systems. Frenulata are unique in that they all have a mid-trunk girdle, spermatophores, sparse peg-like chaetae, and a tube with the posterior end open. [9] [10] The tube serves to provide structure for this soft-bodied animal as well as place the organism in an optimal position to obtain nutrients. [11]

Ecology

Frenulata are one of four clades of Siboglinidae, they are also the most diverse. [12] Despite that, the endosymbiotic bacterial diversity remains largely unknown due to their small size and difficult to reach habitats. They often serve as environmental engineers with their tubes, changing the composition of the sediment. [13] There is evidence that they are symbiote-flexible, meaning they can utilize different species of bacteria in order to best adapt to their environments. This however is still a contested theory with conflicting reports. [5] [11]

References

  1. Southward, Eve C.; Schulze, Anja; Gardiner, Stephen L. (2005). "Pogonophora (Annelida): form and function" . Hydrobiologia. 535–536 (1): 227–251. Bibcode:2005HyBio.535..227S. doi:10.1007/s10750-004-4401-6. ISSN   0018-8158. S2CID   2057727.
  2. Kubota, Norihiro; Kanemori, Masaaki; Sasayama, Yuichi; Aida, Masato; Fukumori, Yoshihiro (2007). "Identification of Endosymbionts in Oligobrachia mashikoi (Siboglinidae, Annelida)". Microbes and Environments. 22 (2): 136–144. doi:10.1264/jsme2.22.136. hdl: 2297/12422 . ISSN   1342-6311. S2CID   84629870.
  3. Hilário, Ana; Capa, María; Dahlgren, Thomas G.; Halanych, Kenneth M.; Little, Crispin T. S.; Thornhill, Daniel J.; Verna, Caroline; Glover, Adrian G. (2011). "New Perspectives on the Ecology and Evolution of Siboglinid Tubeworms". PLOS ONE. 6 (2): e16309. Bibcode:2011PLoSO...616309H. doi: 10.1371/journal.pone.0016309 . PMC   3038861 . PMID   21339826.
  4. Rodrigues, Clara F.; Hilário, Ana; Cunha, Marina R.; Weightman, Andrew J.; Webster, Gordon (2011-06-01). "Microbial diversity in Frenulata (Siboglinidae, Polychaeta) species from mud volcanoes in the Gulf of Cadiz (NE Atlantic)" . Antonie van Leeuwenhoek. 100 (1): 83–98. doi:10.1007/s10482-011-9567-0. ISSN   1572-9699. PMID   21359663. S2CID   10224623.
  5. 1 2 3 4 Meunier, Cédric; Andersen, Ann C.; Bruneaux, Matthieu; Le Guen, Dominique; Terrier, Peran; Leize-Wagner, Emmanuelle; Zal, Franck (2010-01-01). "Structural characterization of hemoglobins from Monilifera and Frenulata tubeworms (Siboglinids): First discovery of giant hexagonal-bilayer hemoglobin in the former "Pogonophora" group". Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 155 (1): 41–48. doi:10.1016/j.cbpa.2009.09.010. ISSN   1095-6433. PMID   19770067.
  6. Pleijel, Fredrik; Dahlgren, Thomas G.; Rouse, Greg W. (2009). "Progress in systematics: from Siboglinidae to Pogonophora and Vestimentifera and back to Siboglinidae" . Comptes Rendus Biologies. 332 (2–3): 140–148. doi:10.1016/j.crvi.2008.10.007. PMID   19281947.
  7. Katz, Sigrid; Klepal, Waltraud; Bright, Monika (2011). "The Osedax Trophosome: Organization and Ultrastructure" . The Biological Bulletin. 220 (2): 128–139. doi:10.1086/BBLv220n2p128. ISSN   0006-3185. PMID   21551449. S2CID   20054373.
  8. Rouse, Greg W. (2001). "A cladistic analysis of Siboglinidae Caullery, 1914 (Polychaeta, Annelida): formerly the phyla Pogonophora and Vestimentifera". Zoological Journal of the Linnean Society. 132 (1): 55–80. doi: 10.1111/j.1096-3642.2001.tb02271.x . S2CID   85356739.
  9. Halanych, Kenneth M. (2005). "Molecular phylogeny of siboglinid annelids (a.k.a. pogonophorans): a review" . Hydrobiologia. 535–536 (1): 297–307. Bibcode:2005HyBio.535..297H. doi:10.1007/s10750-004-1437-6. ISSN   0018-8158. S2CID   16022909.
  10. Karaseva, N. P.; Rimskaya-Korsakova, N. N.; Ekimova, I. A.; Gantsevich, M. M.; Kokarev, V. N.; Kremnyov, S. V.; Simakov, M. I.; Udalov, A. A.; Vedenin, A. A.; Malakhov, V. V. (2021-11-05). "A new genus of frenulates (Annelida: Siboglinidae) from shallow waters of the Yenisey River estuary, Kara Sea" . Invertebrate Systematics. 35 (8): 857–875. doi:10.1071/IS20075. ISSN   1445-5226. S2CID   244151933.
  11. 1 2 Lee, Dh; Kim, Jh; Lee, Ym; Jin, Yk; Paull, C; Kim, D; Shin, Kh (2019-10-10). "Chemosynthetic bacterial signatures in Frenulata tubeworm Oligobrachia sp. in an active mud volcano of the Canadian Beaufort Sea" . Marine Ecology Progress Series. 628: 95–104. Bibcode:2019MEPS..628...95L. doi:10.3354/meps13084. ISSN   0171-8630. S2CID   201194903.
  12. Schulze, Anja (2003). "Phylogeny of Vestimentifera (Siboglinidae, Annelida) inferred from morphology" . Zoologica Scripta. 32 (4): 321–342. doi:10.1046/j.1463-6409.2003.00119.x. ISSN   0300-3256. S2CID   84679292.
  13. Lee, Yung Mi; Noh, Hyun-Ju; Lee, Dong-Hun; Kim, Jung-Hyun; Jin, Young Keun; Paull, Charles (2019). "Bacterial endosymbiont of Oligobrachia sp. (Frenulata) from an active mud volcano in the Canadian Beaufort Sea" . Polar Biology. 42 (12): 2305–2312. Bibcode:2019PoBio..42.2305L. doi:10.1007/s00300-019-02599-w. ISSN   0722-4060. S2CID   207987760.