Read the following paragraph carefully.

According to their body length, sharks fall into three major categories. The shortest body length belongs to hammer-head sharks. They live in tropical waters. These sharks are known for their flattened, T-shaped heads. The length of the body of a hammerhead shark is larger than 3.5 m. Nurse sharks are slow-moving sharks. They live mostly in warm, shallow water. Nurse sharks grow to more than 4 m. Perhaps the largest body belongs to the great white shark. These sharks live in oceans, and most seas of the world. They are mostly found in waters near the Hawaii islands. Great white sharks are perhaps the greatest predators of the sea. The body of an average white shark often reaches a length of over 6 m. Each year, lots of swimmers and surfers are attacked by these wild sharks.


Question: What is the criterion according to which the paragraph has been developed?