Fun with Dorsal Fins

Overview

In this second lesson of the Orca — Tohorā unit, ākonga explore the orca’s dorsal fin as an external body part. They observe, move, talk, and draw to connect the fin with its function: helping the orca stay balanced and move through the water.

Learning intentions

• We are learning to name an orca’s dorsal fin.
• We are learning to describe what the dorsal fin helps an orca do.
• We are learning that animal body parts have different functions.
• We are learning to share our observations using words, drawings, and actions.

Success criteria

• I can point to and name the orca’s dorsal fin.
• I can say that the dorsal fin helps the orca balance and move through water.
• I can draw or label a dorsal fin.
• I can share one idea about how a body part helps an animal.

Curriculum links

• Biological Science — What organisms need to survive: identifying and describing the functions of external body parts in animals.
• Biological Science — How organisms meet their needs: linking animal body parts and behaviours to survival.
• Science capabilities: observing, describing, communicating, and using evidence from real-life examples.
• Te Mātaiaho learning dispositions: curiosity, taking part, and sharing ideas with others.

Lesson structure (45 minutes)

1. 0–5 min · Welcome and recall. Teacher opens with the orca image and wondering question and asks, “What do you remember about tohorā from our last lesson?” Students turn and talk, then share one idea about what orcas need to live. Listen for water, food, air, space, and safety. Accept home-language responses and build on them.

2. 5–12 min · Notice the body part. Teacher displays the labelled orca body picture and slowly introduces dorsal fin, explaining that it is the fin on the orca’s back. Students locate the dorsal fin on the image and make a “fin” shape with one hand. Teacher explains: “The dorsal fin helps the orca stay balanced as it swims. The orca uses other fins and its tail to help steer and move too.” Avoid suggesting that the dorsal fin is used like a propeller.

3. 12–20 min · Move like an orca. Teacher shows the movement demonstration slide and models two actions: balancing with arms out like fins and moving smoothly through an imaginary ocean. Students safely move beside their spot, first pretending to swim without a dorsal fin and then with one hand raised on their back. Pause to ask, “Which way felt easier to balance? What might the dorsal fin help with?” Reinforce that classroom movement is pretend and that students keep space between bodies.

4. 20–30 min · Observe and create. Teacher distributes the dorsal fin observation and drawing sheet and models drawing a simple orca outline, adding a dorsal fin on its back. Students complete the picture, circle or draw the dorsal fin, and add a short dictated, copied, or independently written sentence: “The dorsal fin helps the orca balance.” Adults support students to talk before drawing or writing. Students may use symbols, labels, or oral recording if writing is still developing.

5. 30–38 min · Partner explain. Teacher displays the partner-talk prompts: “This is the ___.” “It helps the orca ___.” Students show their worksheet to a partner and explain the dorsal fin using words, gesture, or pointing. Partners take turns being the “scientist” and the “listener”; the listener responds, “I heard you say…”

6. 38–45 min · Share and check. Teacher gathers the class, revisits the opening image in the final recap slide, and asks, “What is the dorsal fin? What does it help the orca do?” Students contribute answers, demonstrate the fin shape, and complete a quick oral exit check by telling the teacher or an adult one body part and its job. Finish with a class sentence: “An orca’s dorsal fin helps it balance as it swims.”

Resources

• the orca introduction and teaching deck
• the dorsal fin observation and drawing sheet
• Large orca photograph or image for teacher display
• Whiteboard and marker
• Pencils, crayons, and colouring materials
• Optional toy orca or model for observation
• Space beside desks for safe movement

Assessment

• During discussion and movement, check whether students can locate and name the dorsal fin and connect it with balance or swimming.
• Confer during worksheet work: ask, “Show me the dorsal fin. What does it help the orca do?” Record names of students needing further support.
• Use the oral exit check to identify whether each student can name a body part and describe a function. Accept spoken, signed, gestured, or drawn responses.

Differentiation

• Support understanding with a real image, repeated gestures, a consistent sentence frame, and the words orca, tohorā, fin, back, balance, and swim. Model each word clearly and invite students to repeat or point.
• Provide a partially drawn orca, thicker pencils, reduced writing demands, and adult scribing for students developing fine-motor, speech, language, or writing skills.
• EAL learners may first discuss ideas in their strongest language, use home-language names where appropriate, and respond through drawing, movement, pointing, or a familiar language before attempting English.
• Extend confident students by inviting them to add the tail or side fins and explain how each body part helps the orca move, balance, or steer. Do not require technical vocabulary.