Fish Remains, Fins and Fruit: teacher key

Red-Bellied Piranhas, grade 10 edition, written for 10th grade. A genome, a river study and a university team each tell part of the story of what red-bellied piranhas eat. See how the evidence fits together.

Read the book. Print this page for the key.

Questions and answers

1. What were the most relevant food items in the 2020-2021 river study?
   • Fruit
   • Fish remains (answer)
   • Rocks
2. What did the Western Kentucky University team argue?
   • Piranhas eat mostly other fish fins (answer)
   • Piranhas eat only fruit
   • Piranhas eat giant fish
3. About how long are red-bellied piranhas when they mature, in the genome study?
   • 16 meters
   • 1.6 cm
   • 16 cm total length (answer)
4. What determined the pitch of the bark and drum sounds?
   • The river's depth
   • The contraction of the muscles (answer)
   • The color of the fish
5. What does biologist Steve Huskey say piranhas get most of their nutrients from?
   • Clipping the fins of other fish (answer)
   • Eating fruit
   • Digging mud
6. What does opportunistic mean here?
   • Eating only plants
   • Staying hidden
   • Feeding on what is available (answer)

Words

• genome: all its genes
• piscivore: fish eater
• pitch: sound height
• opportunistic: taking what comes
• sequenced: decoded