Amynthas Explained

Amynthas is a genus of earthworms in the family Megascolecidae.^[1] They are known as jumping worms, snake worms, or crazy worms because of their erratic thrashing behaviour when disturbed.^{[2] [3] [4] [5]} The genus is native to East Asia, but they are invasive in many areas of the United States.^[6] They are a matter of concern in many states, as they disrupt the native forest ecology by affecting soil structure and chemistry.^[7]

Appearance

Amynthas species can be differentiated from other earthworms by their clitellum, which is pale, annular, is close to the head, and lies flat against the body.^[8] They vary in size between 3.8and.^[9]

Life cycle

Amynthas species' faster reproduction rate and their ability to reproduce asexually (parthenogenesis) has contributed to their spread into the United States.^[10] The worms reach maturity in 60 days, which allows them to have two hatches per year. Eggs are wrapped in small cocoons, which overwinter while the adults die off at the first freeze each year.^[11] The young then emerge the next spring.^[12]

Species

• Amynthas agrestis (Goto and Hatai, 1899)
• Amynthas alexandri (Beddard, 1900)
• Amynthas assimilis (Hong & Kim, 2002)
• Amynthas borealis (Panha & Bantaowong, 2011)
• Amynthas comptus (Gates, 1932)
• Amynthas defecta (Gates, 1930)
• Amynthas dorualis
• Amynthas exiguus (Gates, 1930)
• Amynthas fucosus (Gates, 1933)
• Amynthas gracilis (Kinberg, 1867)
• Amynthas hilgendorfi (Michaelsen, 1892)
• Amynthas hupbonensis (Stephenson, 1931)
• Amynthas japonicus (Horst, 1883)
• Amynthas kinmenensis
• Amynthas longicauliculatus (Gates, 1931)
• Amynthas luridus (Shen, Chang, & Chih, 2019)^[13]
• Amynthas mekongianus (Cognetti, 1922)
• Amynthas minimus
• Amynthas mirifius
• Amynthas moakensis
• Amynthas morrisi (Beddard, 1892)
• Amynthas mujuensis
• Amynthas obsoletus
• Amynthas papulosus (Rosa, 1896)
• Amynthas phatubensis (Panha & Bantaowong, 2011)
• Amynthas polyglandularis
• Amynthas pulvinus
• Amynthas ruiyenensis (Shen, Chang, & Chih, 2019)
• Amynthas sangumburi
• Amynthas siam (Blakemore, 2011)
• Amynthas srinan (Panha & Bantaowong, 2011)
• Amynthas taiwumontis
• Amynthas tessellatus
• Amynthas tokioensis (Beddard, 1892)
• Amynthas tontong (Panha & Bantaowong, 2011)
• Amynthas wuhumontis
• Amynthas wujhouensis

Notes and References

1. Bantaowong, U. . Chanabun, R. . Tongkerd, P. . Sutcharit, C. . James, S.W. . Panha, S. . amp . 2011 . New earthworm species of the genus Amynthas Kinberg, 1867 from Thailand (Clitellata, Oligochaeta, Megascolecidae) . ZooKeys . 90 . 35–62 . 10.3897/zookeys.90.1121. 21594106 . 3084491 . free .
2. Web site: Asian Jumping Worms . 2022-12-21 . hortnews.extension.iastate.edu . en.
3. Web site: Jumping worm (Amynthas species) Minnesota DNR . 2022-12-21 . www.dnr.state.mn.us . en.
4. Web site: Silver . Jennie . “Jumping Worm” – Amynthas spp. . 2022-12-21 . Extension Richland County . en-US.
5. Web site: details . 2022-12-21 . www.tsusinvasives.org . en.
6. Web site: Amynthas Worms in Maine : Maine DACF . 2022-12-21 . www.maine.gov.
7. Web site: Jumping worms . 2022-12-22 . extension.umn.edu . en.
8. Wisconsin DNR Forest Health. "Jumping Worms (Amynthas spp.) Fact Sheet". Updated April 2015. Accessed Dec 22 2022.
9. Web site: Jumping Worms . 2022-12-22 . www.michigan.gov . en.
10. Web site: Jumping Worm (Amynthas spp.) . 2022-12-22 . Cornell Cooperative Extension . en.
11. Web site: 2021-05-14 . Invasive Asian Jumping Earthworms . 2024-02-01 . Cornell Cooperative Extension . en.
12. Web site: weeks . 2021-07-28 . Jumping/Crazy/Snake Worms – Amynthas spp. . 2022-12-22 . Center for Agriculture, Food, and the Environment . en.
13. Shen, H.-P. . Chang, C.-H. . Chih, W.-J. . amp . 2019 . Two new earthworm species of the genus Amynthas (Oligochaeta: Megascolecidae) from central Taiwan, with comments on some recent species assignments in Amynthas and Metaphire . Zootaxa . 4658 . 1 . 101–123 . 10.11646/zootaxa.4658.1.4. 31716758 .