30 - 45 minutes

Students will compare and contrast features between fish and another group of (vertebrate) animals adapted for life underwater e.g. marine mammals or reptiles.


Background information about fish anatomy can be found in the Fact Sheet: Fish Anatomy.

Student Worksheet: What’s the difference? (Year 3)

This lesson requires students to have access to non-fiction books on (marine) mammals or reptiles and/or the internet.

This lesson assumes students have prior knowledge of features of fish. The Lesson: What’s a Fish? (Year 3) may precede this one if there is no prior knowledge.

Western Australian curriculum

Science Science Understanding Biological sciences ACSSU044
Science Science Inquiry Skills Communicating ACSIS060
English Language Text structure and organisation ACELA1478
English Language Expressing and developing ideas ACELA1484
English Literacy Interacting with others ACELY1676


  1. Recall information from lesson/s about what features are characteristic of fish.
  2. Discuss the features of another group of (vertebrate) animals suited to life underwater – i.e. choose either marine mammals or marine reptiles. What features do you think would be the same or similar? What would be different?
  3. Allow students to work in pairs or small groups with non-fiction books and/or the internet to discover some characteristics of your chosen group of animals.
  4. Following their research time, ask each pair (group) to share a characteristic they discovered. Brainstorm student responses.
  5. Explain to students (if necessary) how to distribute information in a Venn Diagram. Distribute Student Worksheet: What’s the difference? (Year 3) and allow time for students to compare similarities and differences between a fish and your chosen group of animals.
  6. Discuss student answers.
Additional resources

Parish, S. 2008 Amazing Facts about Australian Marine Fishes. Steve Parish Publishing, Queensland.

SeaWorld Parks and Entertainment, Bony Fishes, https://seaworld.org/en/animal-info/animal-infobooks/bony-fish

SeaWorld Parks and Entertainment, Bottlenose Dolphins, https://seaworld.org/en/animal-info/animal-infobooks/bottlenose-dolphins

SeaWorld Parks and Entertainment, Sea Turtles, https://seaworld.org/en/animal-info/animal-infobooks/sea-turtles


fish anatomy, features, classification