Sea slug grows new body after decapitation

Category: Science/Environment


Unlocking Word Meanings

Read the following words/expressions found in today’s article.

  1. regeneration / rɪˌdʒɛn əˈreɪ ʃən / (n.) – the act of growing an organ, tissue, or other body part again after it’s been cut off or destroyed

    Scientists are studying the regeneration of skin after different types of injuries.

  2. decapitate / dɪˈkæp ɪˌteɪt / (v.) – to cut off the head of a person or animal

    The hero in the story decapitated the dragon that was destroying the village.

  3. sea slug / si slʌg / (n.) – a brightly-colored marine animal that looks like a snail without a shell

    I found some sea slugs while I was diving the other day.

  4. weird / wɪərd / (adj.) – strange, unusual, and difficult to understand or explain

    People on the internet are saying that the weird shadow in the photo is a ghost.

  5. parasite / ˈpær əˌsaɪt / (n.) – an organism that lives on or inside an animal or plant and takes food or protection from it

    The vet found parasites in my dog’s stomach.


Read the text below.

Scientists have discovered the ultimate case of regeneration: Some decapitated sea slugs can regrow hearts and whole new bodies.

This “wonder of nature,” reported in a biology journal on March 8, could eventually help scientists better understand and tackle regeneration of human tissue.

Biology researcher Sayaka Mitoh said she loves studying Japanese sea slugs because they are small, cute and weird. They can even briefly photosynthesize like a plant drawing food from the sun.

One day in the lab, she saw something bizarre: A sea slug had decapitated itself and the head kept on moving and living. Then a couple more did the same, according to a study in Current Biology.

So the doctoral student, along with Nara Women’s University aquatic ecology professor Yoichi Yusa, tried it themselves, cutting the heads off 16 sea slugs. Six of the creatures started regenerating, with three succeeding and surviving. One of the three even lost and regrew its body twice.

They said that the species probably developed the feat as a way of fighting off parasites. (AP)

This article was provided by The Japan Times Alpha.

Viewpoint Discussion

Enjoy a discussion with your tutor.

Discussion A

  • The amazing regeneration ability of sea slugs could help scientists better understand and tackle regeneration of human tissue. Do you think we’ll develop the technology to regrow body parts in the future? Why or why not? Discuss.
  • If the technology to regrow human body parts were developed, do you think it would impact daily life in any way (ex. fewer people wearing seatbelts)? Why or why not? Discuss.

Discussion B

  • The researchers think that sea slugs developed the ability to regrow hearts and whole new bodies as a way of fighting off parasites. What do you think about that? Why? Discuss.
  • Are parasites a big concern in your country? Why or why not? Discuss.