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Finding Nemo’s Clownfish

Middle school learnscience.org

Name Date

Predict

In Finding Nemo, Nemo’s mom is lost at the start of the movie, and his dad, Marlin, raises him alone. In a wild clownfish family, could a dad like Marlin become the mom?

Circle one. Yes / No

Why?

Watch

  1. Finding Nemo got the clownfish wrongyoutube.com/shorts/62srRdYYCAg
  2. Nemo is probably not Marlin’s sonyoutube.com/shorts/5GJUhGE19qA

Word of the day

Larva (LAHR-vuh). A young animal, newly hatched from its egg, that looks far different from the adult it will grow into.

Word partComes fromMeaning
larvaLatin larvaghost, mask
  • A tadpole is the larva of a frog.
  • The word for more than one larva is larvae. In video 2, Raven calls newly hatched clownfish larvae.

Bonus word. Protandry (pro-TAN-dree). Prot- means “first,” and andr- means “man” or “male.” A protandrous fish is male first and can become female later. The proton in chemistry got its name from the same Greek word for first.

Questions

  1. In a clownfish group, the biggest fish is the mom, called the breeding female. The second biggest is the dad, called the breeding male. The smaller fish wait in line by size. When the breeding female is gone, what happens to the breeding male? What happens to each fish waiting in line?

    Hint. Clownfish keep their size order. Start with the biggest fish that’s still alive.

  2. Clownfish parents care for their eggs day and night, and they care the most on the night the eggs hatch. Then the baby fish, called larvae, drift away into open water. How does caring for the eggs help clownfish parents if they don’t raise the babies?

    Hint. Think about what could happen to eggs that no parent guards.

  3. Kimbe Island has 310 sea anemones, the stinging sea animals where clownfish make their homes. Of the young fish that moved into these anemones, 56% had hatched from Kimbe Island parents. But family members shared an anemone only about 2% of the time. How can most of Kimbe Island’s young fish come from Kimbe Island parents while family members rarely share an anemone?

    Hint. Compare living on the same island with living in the same anemone.

  4. Baby clownfish drift in open water for about 10 days. The Kimbe Island scientists didn’t follow the babies across the water. How did the Kimbe Island scientists figure out which young clownfish belonged to which parents?

    Hint. In video 2, Raven says the scientists took thousands of little fin clips. What could scientists test in a fin clip?

Exit ticket

In the movie, Nemo grows up in the same home as his dad, Marlin. What two pieces of evidence say a small fish living with Marlin probably isn’t his son?

Hint. Think about where baby clownfish go the night they hatch. Then think about the Kimbe Island numbers.

Sources