Megascolecidae

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Megascolecidae
Megascolecidae found in Sai Kung West Country Park, Hong Kong belonging to genus Amynthas
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Annelida
Clade: Pleistoannelida
Clade: Sedentaria
Class: Clitellata
Order: Opisthopora
Suborder: Lumbricina
Family: Megascolecidae
Rosa, 1891[1]
Genera

Over 65, see text

Megascolecidae is a

earthworms native to Madagascar, Australia, New Zealand, Asia, and North America. All species of the Megascolecidae belong to the Clitellata class.[2] The Megascolecidae comprise a large family of earthworms[3] and they can grow up to 2 meters in length.[4] The intercontinental distribution of Megascolecidae species favours the continental drift theory.[5]

Their large size distinguishes the Megascolecidae from other earthworm families; they are an essential part of maintaining

Annelida phylum. They live in a terrestrial environment and have a preference for soil with high biomass
content, high humidity, and warm temperature. Many different genera of the Megascolecidae have been described, but the total number of species is still unsettled.

Physiological features

Different species of the Megascolecidae have different physiological features, but some similarities of physiological features can be found between species.[6] The family contains relatively large individuals. The length of earthworms can vary from 1.0 cm (0.39 in) to 2 m (6 ft 7 in).[4] The number of spermathecal pores is normally paired, but multiples can be present in some species. The location of spermathecal pores and how they are positioned in different segmental locations is used in the identification of different megascolecidids.[7]

Earthworms ingest a variety of organic materials in the soil since they live in

Chemical digestion mainly occurs in the intestinal caeca of earthworms, which have higher protease activity than other parts of the gut.[8]

Genital markings in the Megascolecidae family can be used to distinguish species.[10]

Reproductive system

The Megascolecidae are

oviparous, laying eggs to reproduce. They are biparental.[11] The ideal condition of reproduction for the megascolecidids is 25 °C, where the eggs hatch the quickest and have the highest cocoon production.[12]

The male reproductive organ of the Megascolecidae includes testes, seminal vesicles, spermathecae, prostate glands,

monoecious. To breed, two earthworms exchange sperm. Long after they are separated, the egg case is secreted. It forms a ring around the worm, then the worm removes the ring from its body and injects its own eggs and the other worm's sperm into it. Afterwards, the egg case is sealed and ready to hatch, grow, and become a cocoon.[15]

Lifecycle

The Megascolecidae lifecycle takes around 50–57 days, depending on the external environments and habitat. The rate of growth during the first 14 days is very low, however; after 21 – 28 days, the rate of growth increases and then cycles up and down throughout the worm's life with no pattern.[16] The growth rate of these worms is correlated to the temperature of their environment. As temperatures increase from 30 °C, a significant growth rate and decreasing the time to sexual maturity are seen. The ideal living temperature of megascolecidids is around 15 to 30 °C.[17] Overall mean growth is 1.79 mg/day, 1.57 mg/day, and 1.34 mg/day depending on the abundance of worms and environment condition and size.[16] The cocoon production of Megascolecidae species also is correlated with the temperature of the environment.[18]

Distribution and habitat

Megascolecidae species can be in Australia, New Zealand, Asia, North America, South America, and Europe.[19] The intercontinental presence of Megascolecidae species can be explained by the Permanence of Continent Theory, which provides the explanation of most Cenozoic distributions; this theory,though, does not explain the presence of European Megascolecidae in North America. The intercontinental distribution of Megascolecidae has two different theories that explains its phenomenon -land bridges and continental drift.[5]

The Megascolecidae family originated in Australia.

West MacDonnell Ranges. G. zeilensis also can be found on the highest point of the mountain where average rainfall of the region is 250 mm annually. This distinguishes them from other species from Graliophilus.[23]

Metaphire and Amynthas are two common genera belonging to the Megascolecidae family. They can be found in different countries in Asia.[24]

Eight different species of Metaphire can be found in

loamy soil.[25]

In Indonesia, 9 different genera can be found; Amynthas, Archipheretima, Metaphire, Metapheretima, Pheretima, Pithemera, Planapheretima, Pleinogaster, and Polypheretima. Pheretimoid is the biggest group of species, which consists of 65 species. Some intrageneric groups are restricted to mainland Asia, but others are native to Indo-Australian Archipelago.[26]

The ideal habitat for Megascolecidae is a terrestrial environment with soil with a high content of

organic material, such as loamy soil,[16] cattlebor pig manure, and aerobically digested sewage sludge.[12] Megascolecidae species grow and produce more cocoons during the summer than the winter, because their lifecycle is highly correlated to the temperature and humidity of the environment.[16] Some Megascolecidae species have adapted to colder temperatures and drier areas, though, which enables them to live in higher-altitude regions of the land.[23]

Ecology

Megascolecidae form an important part of the

agricultural systems or previously areas that are lacking of earthworms would see the biggest impact of the invasive earthworms.[29] The impact of earthworms on soil structure is due to the rate of net nitrogen mineralization.[30]

Genera

References

  1. ^ Rosa, D. (1891). "Die exotischen terricolen des k. k. naturhistorischen Hofmuseums". Annalen des K.K. Naturhistorischen Hofmuseums. 6: 379–406.
  2. ^ "WoRMS - World Register of Marine Species - Megascolecidae Rosa, 1891". www.marinespecies.org. Retrieved 2021-05-20.
  3. ^ "The geographic distribution of the genera in the Pheretima complex (Megascolecidae) in eastern Asia and the Pacific region (English translation)". ResearchGate. Retrieved 2021-05-20.
  4. ^
    PMID 30584390
    .
  5. ^ a b Reynolds, J.W. 1995. The distribution of earthworms (Annelida, Oligochaeta) in North America. Pp. 133- 153 In: Mishra, P.C., N. Behera, B.K. Senapati and B.C. Guru (eds.). Advances in Ecology and Environmental Sciences. New Delhi: Ashish Publishing House, 651 pp.
  6. S2CID 89825577
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  7. doi:10.1093/icb/icm008
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  8. ^
    S2CID 24831606
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  9. PMID 23847816
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  10. ^
    PMID 31966217
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  11. ^
    doi:10.1071/ZO9950489
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  12. ^
    S2CID 12479260
    .
  13. ^ "Parthenogenesis, polyploidy and reproductive seasonality in the Taiwanese mountain earthworm Amynthas catenus (Oligochaeta, Megascolecidae) | Request PDF". ResearchGate. Retrieved 2021-05-21.
  14. PMID 21498920
    .
  15. ^ "Natural history". www.biologicaldiversity.org. Retrieved 2021-05-21.
  16. ^
    PMID 19467590
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  17. S2CID 12479260
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  18. S2CID 24522967
    .
  19. PMID 20951218
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  20. doi:10.3853/j.0067-1975.30.1977.390
    . Retrieved 2021-05-20.
  21. doi:10.1080/00222939700770951
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  22. doi:10.1111/j.1469-7998.1971.tb02200.x
    .
  23. ^
    S2CID 209564871
    .
  24. S2CID 84500164
    .
  25. ^ Ng, Beewah; Bantaowong, Ueangfa; Tongkerd, Piyoros; Panha, Somsak (8 March 2018). "Description of two new species of the earthworm genus, Metaphire (Clitellata: Megascolecidae), from Kedah, Peninsular Malaysia" (PDF). Raffles Bulletin of Zoology. 66: 132–141.
  26. ^ Nugroho, Hari (2010). "A taxonomical review on pheretimoid earthworms (Ollgochaeta: Megascolecidae) from Indonesian archipelago". Indonesia Zoo. 19 (2): 93–108.
  27. ^
    ISBN 978-1-315-16186-0
    , retrieved 2021-05-20
  28. PMID 22247659
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  29. S2CID 18494778
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  30. S2CID 23836511
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  31. ^ Records of the Australian Museum (2021) vol. 73, issue no. 4, pp. 123–129 https://doi.org/10.3853/j.2201-4349.73.2021.1769
  32. ^
    doi:10.24199/j.mmv.1972.33.10
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Megascolecidae&oldid=1219842568"