Animals & Environment
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27 Sept 2026
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The Spiky Secrets of Sea Urchins
Warm-up → Read & Listen → Check Understanding → Language → Use It
WARM UP
Section: Warm Up
Think Ahead: Which detail do you think appears in this story?
a) Sea urchins have soft bodies on the outside.
b) Sea otters use rocks to open sea urchins.
c) Fish never eat spiky sea animals.
Ask:
(1) Have you ever seen a sea animal with sharp spines?
(2) How do you think sea otters stay safe in the water?
VOCABULARY
spiky (/ˈspaɪ.ki/, adjective)
Meaning: Covered with sharp points on the outside.
Example: The sea urchin looks like a spiky ball on the rocks.
ocean (/ˈəʊ.ʃən/, noun)
Meaning: The huge body of salt water that covers most of the Earth.
Example: Many strange animals live deep in the blue ocean.
spines (/spaɪnz/, noun)
Meaning: Long, sharp needles on the body of an animal.
Example: The sea urchin moves its sharp spines slowly.
protect (/prəˈtekt/, verb)
Meaning: To keep someone or something safe from harm.
Example: Hard shells protect small animals from danger.
shell (/ʃel/, noun)
Meaning: A hard outer cover that shields an animal.
Example: The crab hides inside its strong shell.
otter (/ˈɒt.ə/, noun)
Meaning: A playful sea animal with thick fur that swims very well.
Example: The sea otter carries a rock in its paws.
sharp (/ʃɑːp/, adjective)
Meaning: Having a fine edge or point that can cut or pierce easily.
Example: Be careful when you touch a sharp needle.
A sea urchin is a small ocean animal. It lives in the deep blue sea. It looks like a spiky ball. Many sharp spines cover its entire body. The spines are very long and thin. They protect the urchin from dangerous fish every day.
The urchin walks slowly on the rocky ocean floor. It uses tiny tube feet to move around. It has a hard shell under the spiky spines. Many people think that no animal can eat this round creature.
However, many clever ocean animals eat sea urchins for dinner. A sea otter swims quickly in the water. It catches a spiky urchin with its paws. The otter carries a flat rock. It breaks the hard shell on the rock and eats the soft food.
Crabs and big fish also like eating urchins. A crab uses its strong claws. It snaps the sharp spines one by one. Then it opens the shell easily. Hungry fish bite the spines off too. These animals always find a way to eat the urchin!
Exploring the Fascinating Diet of Sea Urchins: Nature’s Spiny Omnivores.©Damsea/Shutterstock.com
DISCUSSION QUESTIONS
1. What does a sea urchin look like?
2. How does a sea otter open a hard shell?
3. Which other ocean animals eat sea urchins?
4. Would you like to see a sea otter in the ocean? Why?
5. Why are sharp spines helpful for small ocean animals?
FILL IN THE GAPS
FILL THE GAPS
Section 1: Fill in the Gaps
Word Bank: otter, protect, sharp, spiky
A sea urchin is a small ocean animal. It lives in the deep blue sea. It looks like a _______(1) ball. Many sharp spines cover its entire body. The spines are very long and thin. They _______(2) the urchin from dangerous fish every day.
The urchin walks slowly on the rocky ocean floor. It uses tiny tube feet to move around. It has a hard shell under the spiky spines. Many people think that no animal can eat this round creature.
However, many clever ocean animals eat sea urchins for dinner. A sea _______(3) swims quickly in the water. It catches a spiky urchin with its paws. The otter carries a flat rock. It breaks the hard shell on the rock and eats the soft food.
Crabs and big fish also like eating urchins. A crab uses its strong claws. It snaps the _______(4) spines one by one. Then it opens the shell easily. Hungry fish bite the spines off too. These animals always find a way to eat the urchin!
Section 2: Main Idea
What is the main idea of this story?
a) Sea urchins are dangerous fish that hunt sea otters.
b) Sea urchins have sharp spines, but many ocean animals find ways to eat them.
c) Sea otters only eat plants on the ocean floor.
UNDERSTANDING
Section 3: True or False
1. A sea urchin looks like a smooth rock. T/F
2. The sea otter uses a flat rock to break the urchin's shell. T/F
3. Crabs cannot break sea urchin spines with their claws. T/F
Section 4: Put Events in Order
Put these steps in order (1-3) to show how an otter eats a sea urchin:
_ The otter catches a spiky sea urchin in the water.
_ The otter eats the soft food inside the shell.
_ The otter uses a flat rock to break the hard shell open.
LANGUAGE
Section 5: Vocab Match
1. spiky
2. ocean
3. protect
4. shell
5. otter
a) a playful sea animal with thick fur
b) having many sharp points on the outside
c) a hard outer cover on an animal
d) to keep safe from harm or danger
e) the large salt water sea where fish live
USE IT
Section 6: Discussion Builder
1. Sea otters swim in the sea _______ they are hungry.
a) because
b) but
c) under
2. Crabs use strong claws _______ open hard shells.
a) to
b) from
c) on
Section 7: Sentence Unscramble
1. A. spiky ball / B. looks / C. sea urchin / D. a / E. like
2. A. flat rock / B. breaks / C. the otter / D. with a / E. the shell
ANSWER KEY
Complete Answer Key - Level A1
Warm Up Answer: b) Sea otters use rocks to open sea urchins.
Section 1: (1) spiky, (2) protect, (3) otter, (4) sharp
Section 2: b
Section 3: 1. False, 2. True, 3. False
Section 4: 1, 3, 2
Section 5: 1-b, 2-e, 3-d, 4-c, 5-a
Section 6: 1-a, 2-a
Section 7: 1. C-B-E-D-A (A sea urchin looks like a spiky ball.), 2. C-B-E-D-A (The otter breaks the shell with a flat rock.)
Section 8: Student answers will vary.
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