Cephalorhynchus hectori, commonly known as Hector’s dolphin, is a small, coastal dolphin species endemic to the waters of New Zealand. It is one of the smallest members of the oceanic dolphin family, displaying unique characteristics that distinguish it from other dolphins. This species is considered critically endangered, facing threats from various human activities, including fishing gear entanglement, habitat degradation, and pollution.
Description & Characteristics
Cephalorhynchus hectori is characterized by its small size, typically reaching a maximum length of 1.5 meters. Its body is slender and fusiform, with a prominent dorsal fin situated in the middle of its back. The dorsal fin is triangular, with a curved leading edge and a rounded tip. The flippers are relatively short and broad, and the tail flukes are broad and notched at the tip. The coloration of Cephalorhynchus hectori is unique, featuring a distinctive pattern of dark and light grey markings. The back and flanks are a dark grey, while the belly and underside are white. A prominent, dark grey band extends from the eye to the flipper, and another band runs horizontally across the chest. The face is often lighter grey, with a darker patch around the eye.
Habitat and Occurrence
Cephalorhynchus hectori is found exclusively in the coastal waters of New Zealand. It is primarily found in the waters of the South Island, with a smaller population inhabiting the North Island. The species is most commonly observed in shallow, inshore waters, particularly around rocky shores and estuaries. It is often found in areas with strong tidal currents and high productivity, where abundant prey is available. Cephalorhynchus hectori is a coastal species, preferring waters shallower than 100 meters. It is rarely found in deeper offshore waters, and its distribution is primarily limited to the New Zealand Exclusive Economic Zone.
Taxonomy
Cephalorhynchus hectori belongs to the Class: Mammalia, Order: Cetartiodactyla, and Family: Delphinidae. This classification places it within the group of marine mammals known as toothed whales, which includes other dolphins, porpoises, and whales. Within the Delphinidae family, Cephalorhynchus hectori is further classified as part of the Cephalorhynchus genus, which encompasses several other small, coastal dolphin species.
Feeding
Cephalorhynchus hectori is a carnivorous species, feeding primarily on a variety of fish, squid, and crustaceans. Its diet varies depending on the location and season, with prey availability playing a significant role. It is an opportunistic feeder, taking advantage of the abundance of prey in its coastal habitat. Cephalorhynchus hectori forages by using echolocation to detect and locate prey. The species typically hunts near the bottom of the water column, feeding on benthic organisms such as flatfish, crabs, and shrimps. It is also known to hunt in schools of fish, using its agility and speed to capture prey.
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