| Species | Weight of Brain | Body Weight | Ratio (weight) brain : body |
|---|---|---|---|
| Blue Whale | 6,900 g | 100,000 kg | 1 : 14,500 |
| Sperm Whale | 9,200 g | 50,000 kg | 1 : 5,435 |
| Humpback Whale | 7,500 g | 30,000 kg | 1 : 4,000 |
| Dugong | 250 g | 260 kg | 1 : 1,040 |
| Indian Elephant | 6,000 g | 5,000 kg | 1 : 833 |
| Gorilla | 500 g | 160 kg | 1 : 320 |
| Monkey | 75 g | 13 kg | 1 : 173 |
| Bottlenose Dolphin | 1,500 g | 250 kg | 1 : 167 |
| Striped Dolphin | 1,200 g | 150 kg | 1 : 125 |
| Human Beings | 1,400 g | 60 kg | 1 : 43 |
| Mouse | 2 g | 25 g | 1 : 13 |
(Source : Dr. Kamiya, Tsukuba University, Japan)
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