Neophocaena – Finless porpoise

A genus of porpoises known commonly as the finless porpoises, distinctively recognized for their lack of a dorsal fin, a feature that sets them apart from most other cetaceans. This genus comprises several species, including the Yangtze finless porpoise and the narrow-ridged finless porpoise, all primarily found in coastal and freshwater environments of Asia, ranging from the Yangtze River in China to coastal waters around Japan, Korea, and Southeast Asia.

The most striking physical characteristic of Neophocaena porpoises is their smooth, rounded backs, where a dorsal fin is typically expected. This adaptation may help them navigate the shallow and murky waters where they live, aiding in stealth and maneuverability. Their bodies are sleek and streamlined, and they have a thick layer of blubber to help in thermoregulation. Their skin is usually a soft gray color, which can vary slightly between species and individuals, and they sometimes exhibit lighter undersides.

Finless porpoises are relatively small compared to other marine mammals, usually not exceeding 2 meters (7 feet) in length. They have a rounded head with no beak, which gives them a distinctively blunt facial profile. One of the charming features of Neophocaena is their facial expressions; the structure of their mouth and head often appears to be smiling. This “smile,” combined with their playful nature, endears them to observers and researchers.

These porpoises are known for their shyness and elusiveness. They tend to avoid boats and are rarely seen in large groups, typically living solitary lives or in small groups of two or three. Neophocaena species use echolocation to navigate and hunt, emitting clicks and listening for the echoes that bounce back from fish and other prey. This ability is crucial for their survival in often turbid waters where visibility is low.