👩‍🏫 Teacher’s Guide

Objective
Students will describe key features of at least one marine mammal and one cephalopod, explain how each is adapted to life in the ocean, and use numbers (length and size) to reason about ocean animals.

Vocabulary
ocean, marine, marine mammal, cephalopod, krill, baleen, mantle, tentacle, jet propulsion, predator, prey, adaptation, depth, oxygen, beak, camouflage

Teaching Notes

• Begin by asking: “What animals do you think live deep in the ocean?” List student ideas and circle any that are mammals vs. invertebrates.
• Introduce the two focus animals: the blue whale and the giant squid. Show how one breathes air at the surface and the other lives deep under water.
• Make a simple comparison chart (size, body parts, how they breathe, what they eat, how they move).
• Use a tape measure or marked string to show the huge lengths (e.g., 25 ft vs 90 ft vs 43 ft). Let students stand along the “whale” or “squid” to feel the scale.
• Emphasize that even gentle animals like blue whales can be very large, and that some animals are mysterious because they live deep where people rarely go.
• Link to critical thinking: students will sort facts, ask “why” questions, and notice cause‑and‑effect (for example, “Because the squid lives deep in the dark, it has huge eyes”).
• If possible, have students write three “I used to think…, now I think…” statements about ocean animals after the lesson.

🧒 Student Worksheet

Concept and Helping Material

Main Concept
Ocean animals have special body parts and behaviors that help them live in salt water. A marine mammal like a blue whale breathes air with lungs and must come to the surface. A cephalopod like a giant squid has no bones, uses tentacles to catch food, and moves by pushing water out of its body.

Helping ideas and samples:

• Blue whale (marine mammal)
  • Largest known animal on Earth
  • Breathes air through a blowhole and must surface to breathe
  • Has smooth, gray‑blue skin and a tail called a fluke
  • Eats tiny shrimp‑like animals called krill
  • Uses baleen plates to strain food from the water
• Giant squid (cephalopod)
  • Very large invertebrate with no bones
  • Has a soft body with a mantle, 8 arms, and 2 long tentacles
  • Uses jet propulsion: pulls water into its body and pushes it out to move
  • Has huge eyes to see in deep, dark water
  • Uses a sharp beak to cut up fish and other squid
  • Can release dark ink to confuse predators

Think: Both animals are very large, but in what ways are they the same? In what ways are they different?

Vocabulary and Definition

• — a very large body of salty water that covers most of Earth
• — living in, on, or near the sea
• — a warm‑blooded animal that lives in the ocean, breathes air, and nurses its young
• — an ocean animal like a squid or octopus with many arms around its head
• — tiny shrimp‑like animals that many whales eat
• — comb‑like plates in some whales’ mouths used to strain food from water
• — the main body of a squid where its organs are found
• — a long, flexible arm used for grabbing or feeling
• — a way of moving by pushing water or air out of the body
• — an animal that hunts and eats other animals
• — the animal that is hunted and eaten
• — a body part or behavior that helps an animal survive
• — how far down something is below the surface
• — the gas in air and water that animals need to live
• — a hard, pointed mouth part used by some animals to bite or tear food
• — colors or patterns that help an animal blend in

Words to Learn

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Sentences to Fill In

1. A blue whale is a _____ _____ because it breathes air and nurses its young.
2. A giant squid is a _____ that has many arms and no bones.
3. The tiny animals called _____ are the main food of blue whales.
4. A blue whale uses _____ plates to strain food out of the water.
5. A squid’s main body, called the _____, holds its organs.
6. Squid arms and _____ are lined with suckers to grab prey.
7. When a squid pushes water out to move, it is using _____ _____.
8. The blue whale’s size and the squid’s ink are both _____ that help them survive.

Think & Respond Q&A

1. How do we know a blue whale is a mammal and not a fish?

2. Why does a blue whale eat tiny krill instead of big fish, even though it is huge?

3. How do a whale’s and a squid’s eyes help them in their habitats?

4. What is one way a whale and a squid both protect themselves?

5. The longest giant squid found was about 43 feet long. If a football field is 360 feet, about how many such squid would fit end to end along the field?

6. Why are giant squid rarely seen by people?

7. How does jet propulsion help a squid escape from danger?

8. If a giant squid has 8 arms and 2 tentacles, how many arms and tentacles would 5 giant squid have?

9. What might happen to ocean food webs if blue whales disappeared?

10. If you could be a blue whale or a giant squid for one day, which would you choose and why?

Hands-On Experiment or Activities

Activity 1: Ocean Size Walk
What You Need: tape measure or meter stick, chalk or tape, open space (hallway or playground).
What You Do:

1. Mark a line for the length of a blue whale (for example, 90 feet) and a line for the length of a giant squid (43 feet). If you do not have room, use a smaller scale (such as 1 foot = 3 feet of animal).
2. Have students stand along each line shoulder to shoulder to see how many students long each animal would be.
3. Compare the two animals by counting steps or tiles.
   Think and Talk:

• Which animal is longer based on your model?

Activity 2: Build‑Your‑Own Ocean Animal
What You Need: paper, crayons, scissors, glue.
What You Do:

1. Draw and cut out body parts: tails, fins, flippers, arms, tentacles, eyes, mouths.
2. Glue the parts together to make a new “ocean animal.” Give it a name.
3. Decide which parts are adaptations for breathing, moving, catching food, and staying safe.
   Think and Talk:

• What adaptations did you give your animal, and how do they help it survive?

Reflection

• What did you learn about the way blue whales get their food?

• What did you learn about how giant squid move and hunt?

• How are marine mammals and cephalopods alike? How are they different?

• What questions do you still have about life in the deep ocean?