Hector's dolphins (Cephalorhynchus hectori) are small, coastal dolphins found only in New Zealand waters. They are the smallest and rarest of the four dolphin species found in New Zealand, and are classified as "nationally endangered." Hector's dolphins have several unique structural features that contribute to their distinctive appearance.
Size and Body Shape:
- Hector's dolphins are relatively small, with an average length of about 1.4 to 1.6 meters (4.6 to 5.2 feet). They have a robust and compact body shape, with a well-defined melon and a narrow, pointed beak.
Flippers and Dorsal Fin:
- The flippers of Hector's dolphins are relatively short and broad, measuring about 25 to 35 centimeters (9.8 to 13.8 inches) in length. They have a distinctive black and white color pattern, with a dark gray or black coloration on the upper surface and a white or light gray coloration on the underside.
- The dorsal fin is triangular in shape and is located about two-thirds of the way along the body. It is usually dark gray or black in color and has a relatively low profile.
Tail Flukes:
- The tail flukes of Hector's dolphins are broad and rounded, with a distinct notch in the center. They are black or dark gray in color and have a white or light gray border.
Coloration:
- Hector's dolphins have a distinctive black and white color pattern. The upper body is generally black or dark gray, while the belly and sides are white or light gray. The boundary between these two colors is often sharply defined, giving the dolphins a striking appearance.
Head and Melon:
- The head of Hector's dolphins is relatively small and rounded, with a well-defined melon located at the front. The melon is a soft, bulbous structure that is used for echolocation and is thought to play a role in communication and prey detection.
Eye Placement:
- Hector's dolphins have their eyes located on the sides of their head, providing them with a wide field of vision. Their eyes are relatively small and dark in color.
In addition to these structural features, Hector's dolphins also have a distinctive blowhole that is located on the top of their head. The blowhole is a specialized opening through which dolphins breathe, and it is surrounded by a small area of black skin.
Overall, the structural features of Hector's dolphins contribute to their unique appearance and enable them to adapt to their coastal habitats and foraging behaviors in New Zealand waters.