Magelona dakini

Magelona dakini
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Annelida
Clade: Pleistoannelida
Clade: Sedentaria
Order: Spionida
Family: Magelonidae
Genus: Magelona
Species:
M. dakini
Binomial name
Magelona dakini
(Jones, 1978)[1]

Magelona dakini is a small, thin, shovel-nosed burrowing worm with limited mobility.[2][3] Adults grow up to 70mm long.[3] Magelonids build meandering burrows, usually below the top 20mm of sediment, in medium to fine sands.[3] They occur across the mid-intertidal and subtidal zones to the continental slope.[3]

M. dakini is important to researchers because it can be used to gauge an ecosystem's health. Under normal conditions, this worm can be dispersed and wide spread in the marine soil.[4] However, when a ecosystem becomes polluted, M. dakini will start to die off and will only be found in non contaminated areas.[5] When the area is cleaned, M. dakini will repopulate. This species is not especially susceptible to metal loading, meaning, excess iron and lead does not affect it much.

In 2020, a paper described a new fossil from the Canglangpu formation of China was described.[6] Dannychaeta tucolus lived about 514 million years ago, putting it in the middle Cambrian. Known from multiple fossils, this species is morphologically very similar to M. dakini, meaning M. dakini features are very basal and has not changed much since the middle Cambrian. Similar to M. dakini, D. tucolus is also characterized by two spindles that are located next to its mouth and lived in shallow borrows on the sea floor as indicated by trace fossils and intact trace fossils with D. tucolus inside of them. D. tucolus is considered a crown-group annelid, meaning it is one of the first unambiquous annalids.

  1. ^ Jones, Meredith (1978). "Three new species of Magelona (Annelida, Polychaeta) and a redescription of Magelona pitelkai Hartman". Proceedings of the Biological Society of Washington. 91 (1): 336–363.
  2. ^ Harris, R; Pilditch, C; Greenfield, B; Moon, V; Kröncke, I (2016). "The Influence of Benthic Macrofauna on the Erodibility of Intertidal Sediments with Varying mud Content in Three New Zealand Estuaries". Estuaries and Coasts. 39 (3): 815–828. doi:10.1007/s12237-015-0036-2. JSTOR 44857719. S2CID 130923697. Retrieved 2021-02-18.
  3. ^ a b c d Singleton, Nathan (2010). Regional Estuary Monitoring Programme (REMP) Data Report: Benthic Macrofauna Communities and Sediments – July 2007 to April 2008 (Report). Waikato Regional Council. Retrieved 2021-02-18.
  4. ^ Thrush, S. F.; Hewitt, J. E.; Pridmore, R. D. (1989-09-01). "Patterns in the spatial arrangements of polychaetes and bivalves in intertidal sandflats". Marine Biology. 102 (4): 529–535. doi:10.1007/BF00438355. ISSN 1432-1793. S2CID 83789435.
  5. ^ Ellis, J. I.; Clark, D.; Atalah, J.; Jiang, W.; Taiapa, C.; Patterson, M.; Sinner, J.; Hewitt, J. (2017-09-20). "Multiple stressor effects on marine infauna: responses of estuarine taxa and functional traits to sedimentation, nutrient and metal loading". Scientific Reports. 7 (1): 12013. doi:10.1038/s41598-017-12323-5. ISSN 2045-2322. PMC 5607226. PMID 28931887.
  6. ^ Chen, Hong; Parry, Luke A.; Vinther, Jakob; Zhai, Dayou; Hou, Xianguang; Ma, Xiaoya (July 2020). "A Cambrian crown annelid reconciles phylogenomics and the fossil record". Nature. 583 (7815): 249–252. doi:10.1038/s41586-020-2384-8. ISSN 1476-4687. PMID 32528177. S2CID 219567905.