Although there is just one species of Bottlenose Dolphins, there two ecotypes, a coastal variant and a deep-water type. The coastal dolphins are about 9 feet long and weigh 500 pounds, while the deeper dwellers are 12 feet long and weigh about 1000 pounds. Scientific Name: Tursiops truncatus. Characteristics: This active dolphin appears to be leaping from the water, revealing the playful face and apparent smile for which the species is famous.