The dolphin family, which evolved in the late Miocene around 10 million years ago, is a relatively modern group of species with the highest diversity among all cetaceans. They are found in the Pacific, Atlantic, and Indian Oceans.

Dolphins are remarkable creatures. They are mammals, not fish—despite living in the ocean—and compared to other animals, they possess highly developed brains capable of complex social communication, learning, memory, problem-solving, and tool usage. Dolphins are quite intelligent!

They are loved by people all over the world for their adorable appearance. Let's discuss some facts about dolphins together, showcasing their intelligence and beauty.

In Mississippi, dolphins were trained to collect trash and then exchange it for fish. Seems straightforward, right? Well, a dolphin named Kelly took it up a notch. She collected a few pieces of paper, tore them into small bits, and then traded them for fish, getting more fish than she could with larger pieces. This demonstrates dolphins using their intelligence to gain greater rewards.

Later, this dolphin caught a seagull in her pool and received a whole box of fish as a reward. Instead of consuming the fish immediately, she left them in a secluded spot to attract more seagulls, even teaching her offspring the "seagull baiting" technique.

2. They have excellent imitation skills.

Dolphins are among the few animal species on Earth capable of imitation. They mimic human sounds and behavior. They can even mimic sounds not present in their ecosystem! They can mimic human actions as well, although they do so only to receive rewards. This shows they can use their fins like human arms.

3. Dolphin brain structure.

Relative to their body size, dolphins have very large brains. The dolphin brain weighs about 2% of its body weight, compared to 2.1% for humans, 1.3% for chimpanzees, and 0.9% for cats.

Dolphin brain capacity is also remarkable; some species like the killer whale and the sperm whale even exceed humans. The killer whale's brain capacity is about 5900 cubic centimeters, the sperm whale's about 7800 cubic centimeters, while the human brain's is about 1350 cubic centimeters.

The dolphin brain is not only large but also complex. It has many convolutions and folds, indicating more neurons and synapses for more information processing and storage. The dolphin's cerebral cortex, responsible for higher cognitive functions, is thicker than that of humans. Dolphins also have a special region called the paralimbic lobe, which connects emotional and rational parts and may be related to their social and emotional abilities.

4. They use sponges as masks.

This might sound illogical, but dolphins wear sponges on their faces in the ocean. Not for sneak attacks on other dolphins or for mischief, but to protect their noses from underwater crabs and rocks.

5. They have self-awareness.

Perhaps the most shocking, especially in discussions about animals, is that dolphins have self-awareness.

This was tested by marking a dot on their foreheads and leading them to a mirror. Dolphins immediately notice something off about their usual appearance, proving they know what they look like. This is unique in the animal kingdom.

6. Abstract thinking.

Dolphins can express their desires or needs through a symbol system, such as pressing buttons of different colors or shapes to request food or toys. This ability indicates that dolphins possess a certain level of abstract thinking and symbol understanding.