Pantropical Spotted Dolphin

The pantropical spotted dolphin, scientifically known as Stenella attenuata, is a widely distributed marine mammal found throughout the world's temperate and tropical oceans. This species became well-known due to a historical threat posed by tuna fishing practices, which led to significant numbers of dolphin deaths. However, the introduction of "dolphin-friendly" tuna fishing techniques in the 1980s helped their populations recover, especially in the eastern 🌊 Pacific Ocean, making them one of the most populous dolphin species today.

First described in 1846 by John Gray, the pantropical spotted dolphin was initially confused with the Atlantic spotted dolphin, but they are now recognized as separate species. The dolphin's name reflects its slender shape, derived from Latin origins. There are two main subspecies: the offshore pantropical spotted dolphin (Stenella attenuata) found globally in tropical waters, and the coastal pantropical spotted dolphin (Stenella graffmani) located in the eastern tropical Pacific coastal areas. A third, unnamed subspecies has been identified in Hawaiian waters.

These dolphins exhibit notable variation in size and spotting. Coastal dolphins are generally larger and more spotted than their pelagic counterparts. Young dolphins are uniformly colored and might be mistaken for bottlenose dolphins, while adults become increasingly spotted. 🌊 Gulf of Mexico populations, however, may have fewer spots, making them difficult to distinguish from Atlantic spotted dolphins.

The pantropical spotted dolphin is easily identified by its streamlined body, dark cape, and long, slender beak. It has the narrowest, curved dorsal fin among dolphin species. Both jaws are dark with white edges, and its underbelly ranges from white to pale gray with sparse spotting. The dolphin's sides feature three distinct color gradients.

Information about their vocalizations is limited, particularly from populations in the South Atlantic. These dolphins are energetic and often engage in high jumps and bow-riding alongside boats. In the eastern Pacific, they are frequently found with yellowfin tuna, although they share a diet of small epipelagic fish instead of preying on each other. They also consume squid and crustaceans in different regions.

Newborn dolphins measure about 80–90 cm (31–35 inches) in length, growing to about 2.5 meters (8 feet) as adults, with a weight ranging from 110 to 140 kg (242 to 309 pounds). Females reach sexual maturity at about 10 years old, while males mature at 12 years, with an average lifespan of 40 years.

These dolphins are typically found in warm, shallow waters above 25°C (77°F), between latitudes 40°N and 40°S, making them prevalent in the Atlantic and 🌊 Indian Oceans. With a global population exceeding three million, they are the second most abundant cetacean worldwide, despite a decrease from an estimated seven million in the 1950s. The species is commonly observed in the Agoa Sanctuary in the Lesser Antilles, though precise studies on their population dynamics and movements within this region are lacking.