BACKBONE OR NO BACKBONE Grades 3RD-5TH | Slides Animal Biology ... - Free Printable

Explanation:
We need to sort the listed animals into two groups: Vertebrates (animals with backbones) and Invertebrates (animals without backbones).

Let’s go through each animal one by one and decide:

1. Jellyfish – No backbone → Invertebrate
2. Lion – Mammal, has spine → Vertebrate
3. Sea star – Echinoderm, no true backbone (has internal calcified plates but not a vertebral column) → Invertebrate
4. Earthworm – Soft-bodied, no bones → Invertebrate
5. Crocodile – Reptile, has backbone → Vertebrate
6. Sponge – Simple animal, no tissues or organs like bones → Invertebrate
7. Jaguar – Mammal → Vertebrate
8. Shark – Fish; has cartilage skeleton, but *still a vertebrate* (vertebrae made of cartilage count!) → Vertebrate
9. Butterfly – Insect → Invertebrate
10. Octopus – Mollusk, no backbone → Invertebrate
11. Frog – Amphibian → Vertebrate
12. Eagle – Bird → Vertebrate
13. Spider – Arachnid → Invertebrate
14. Crab – Crustacean → Invertebrate
15. Hagfish – This is tricky! Hagfish are jawless fish. They have a notochord (a flexible rod), but *no true vertebrae*. However, in most elementary science curricula (especially grades 3–5), hagfish are classified as vertebrates because they belong to the phylum *Chordata* and are considered primitive vertebrates — many textbooks include them as vertebrates. But some sources say they’re *not* true vertebrates. Let’s check standard grade-level expectations: In K–5 science, animals like fish (including sharks and hagfish) are usually grouped as vertebrates. Also, the image includes “Shark” as a vertebrate (correct), and hagfish are similar. So for this level, Hagfish = Vertebrate.

Now let’s list them clearly:

Vertebrates:
- Lion
- Crocodile
- Jaguar
- Shark
- Frog
- Eagle
- Hagfish

That’s 7.

Invertebrates:
- Jellyfish
- Sea star
- Earthworm
- Sponge
- Butterfly
- Octopus
- Spider
- Crab

That’s 8.

Double-check: Total animals = 15. 7 + 8 = 15 ✔

Final Answer:
Vertebrates: Lion, Crocodile, Jaguar, Shark, Frog, Eagle, Hagfish
Invertebrates: Jellyfish, Sea star, Earthworm, Sponge, Butterfly, Octopus, Spider, Crab