Giant Clams

Published: 2.28.2018
Level 5   |   Time: 5:27
Accent: Chinese
Source: TED Talks

A marine biologist shares why she wants to turn the legendary sea creatures into heroes of the oceans.


triangle Directions

  1. REVIEW the vocabulary / background.
  2. WATCH the video.
  3. ANSWER the questions.
  4. CHECK your answers. (Show Answers)

triangle Vocabulary

  • nonstop [adv] - without stopping
  • massive [adj] - very big
  • man-eaters [n] - things that eat humans
  • lie in wait [exp] - wait very still
  • unsuspecting [adj] - not suspicious, relaxed
  • bait [n] - food used to trap something
  • retrieve [v] - take
  • retreat [v] - back up, run away
  • a myth [n] - a false idea
  • a delicacy [n] - an expensive, rare, tasty food
  • a hinge [n] - the opening and closing part of a door
  • extinction [n] - non-existence
  • ornamental [adj] - decorative
  • go out of their way [exp] - give extra effort
  • fossilized [adj] - bone turned into fossil
  • so-called [adj] - name is different from reality
  • a clamity [pun] - sounds like 'calamity' which means a disaster
  • charismatic [adj] - more personality
  • a fascination [n] - a strong interest
  • ecology [n] - life
  • breeding [v] - making babies
  • multitasking [adj] - doing multiple things at the same time
  • in a nutshell [exp] - summarized
  • vital indicators [n] - very important signs
  • a canary [n] - a type of bird
  • a canary in a coalmine [exp] - an early warning of possible problems or danger
  • depleted [adj] - made very small
  • paramount [adj] - very important

[n] - noun,  [v] - verb,  [phv] - phrasal verb,  [adj] - adjective,  [exp] - expression

triangle Questions

  1. What are Mei Lin's nicknames at home? (Check all that apply.)
    The Mother of Clams
    The Giant Girl
    The Clam Girl
    The Giant Clam Girl
    Clam Queen

  2. Are giant clams the largest type of sea animal?

  3. How much did the largest giant clam weigh?
    Slightly less than 3 baby elephants
    The same as 3 baby elephants
    More than 3 baby elephants

  4. Did Mei Lin believe the legend about a diver losing his legs to a clam?
    Yes, because she knew how big the clams were.
    No, because she knew clams could not bite.
    Probably, because she did an experiment.
    Probably not, because she used herself as bait.

  5. Why does she think that the giant clams do not bite?
    They cannot bite.
    They don't enjoy the taste of humans.
    They would rather protect themselves.

  6. Which statements about giant clams are true? (Check all that apply.)
    Humans are the biggest threat to their existence.
    They are considered a delicacy in many places.
    Fishermen hunt them for their adductor muscles.
    They are used for jewelry.

  7. When were giant clams almost hunted to extiction?
    Between the 1960s and 1980s
    Between the 1970s and 1980s
    Between the 1960s and 1990s

  8. Why is it easy to forget about giant clams?
    Other animals get more attention.
    They are not endangered.
    They are not intelligent.

  9. What surprising giant clam ability did she discover?
    They are able to mate without a partner.
    They are able to walk.
    They are able to talk.

  10. How might this ability be useful for giant clams? (Check all that apply.)
    They can get away from predators.
    They can communicate danger to other clams.
    The can find mates.
    They can find more food.

  11. How do giant clams impact coral reefs? (Check all that apply.)
    They build reefs.
    They produce food.
    They protect shrimps and crabs.
    They filter water.

  12. How many giant clams are alive today?
    The same as usual
    More than 50% of the usual amount
    Less than 50% of the usual amount

triangle Script

Back home, my friends call me nicknames, such as "The Giant Clam Girl," "Clam Queen," or, "The Mother of Clams."


This is because every time I see them, I talk nonstop about giant clams all day, every day. Giant clams are these massive and colorful shelled marine animals, the largest of its kind. Just look at this shell. The biggest recorded individual was four-and-a-half-feet long and weighed about 550 pounds. That is almost as heavy as three baby elephants.

South Pacific legends once described giant clams as man-eaters that would lie in wait on the seabed to trap unsuspecting divers. A story goes that a diver had lost his legs while trying to retrieve a pearl from a giant clam. I thought, "Really?" So out of curiosity, I did an experiment using myself as bait.


I carefully placed my hand into the clam's mouth and waited.Hmm ... I still have my hand. It seems that these gentle giants would rather retreat and protect their fleshy bodies than feed on me. So much for those killer clam myths!

Unfortunately, the reality is, we are the giant clams' biggest threat.Considered a delicacy throughout the Western Pacific and Indian Oceans, giant clams have been traditionally fished as seafood.Fishermen are particularly interested in their adductor muscles,which are organs that hold the two shells together like a hinge.Just for their muscles, giant clams were almost hunted to extinction between the 1960s and 1980s. Clamshells are also popular in the ornamental trade as jewelry and for display. In the South China Sea, fishermen went out of their way to collect fossilized clamshells by digging through large areas of coral reefs.These were later carved and sold as so-called "ivory handicrafts" in China. Giant clams, dead or alive, are not safe from us. It's a "clamity!"



With the spotlight on more charismatic marine animals such as the whales and coral reefs, it is easy to forget that other marine life needs our help, too. My fascination with giant clams got me started on conservation research to fill in the knowledge gaps on their ecology and behavior. One of the discoveries that we made was that giant clams could walk across the seafloor. Yes, you heard me right: they can walk.

To find out, we placed numerous baby clams on a grid. Now watch what happens over 24 hours. We think that walking is important for getting away from predators and finding mates for breeding. While it can hard to imagine any movement in these enormous animals,giant clams up to 400 pounds can still walk, they just move slower.

During my PhD, I discovered more secrets about the giant clams.But there was something missing in my work. I found myself asking, "Why should people care about conserving giant clams?" -- other than myself, of course.


It turns out that giant clams have a giant impact on coral reefs.These multitasking clams are reef builders, food factories, shelters for shrimps and crabs and water filters, all rolled into one. In a nutshell, giant clams play a major contributing role as residents of their own reef home, and just having them around keeps the reef healthy. And because they can live up to 100 years old, giant clams make vital indicators of coral reef health. So when giant clams start to disappear from coral reefs, their absence can serve as an alarm bell for scientists to start paying attention, similar to the canary in a coal mine. But giant clams are endangered. The largest clam in the world is facing the threat of extinction, with more than 50 percent of the wild population severely depleted.And the ecological benefits of having giant clams on coral reefsare likely to continue only if populations are healthy, making their conservation paramount.

So I stand here today to give a voice to the giant clams, because I care a whole lot for these amazing animals, and they deserve to be cared for. It is time for the giant clams to step out of their shells, and show the world that they, too, can be the heroes of the oceans.

Thank you very much.