Male spinner dolphins are typically bigger than females, but both sexes can range anywhere from 4 to 7 feet in length and weigh approximately 130 to 180 pounds. Spinner dolphin coloration can vary across the globe, but they are mostly seen in shades of dark/light grey, black, and white; they are darker in color on the top and sides and have a white underbelly.

Spinner dolphins are identified from one another by their dorsal fins, each dolphin has a set of fins that is distinctive from other dolphins. These dolphins are long and lean, with a characteristically slender beak.

Spinner dolphins are found throughout the world, but are mostly known for living off the coast of the Hawaiian islands. The dolphins that live near Hawaii are incredibly sociable with the people visiting the beaches and swimming off shore, coming up to them and giving them the chance to “swim with dolphins”. 

They also live in the Pacific Ocean, Indian Ocean, and the tropical portion of the Atlantic Ocean. Spinner dolphins, excluding those off of Hawaii’s shore, tend to spend most of their time in deeper water way of the coastline.

Spinner dolphins are nocturnal, carnivorous hunters and their prey of choice includes fish, shrimp, and squid. Studies have shown that they prefer lanternfish in particular. 

Their prey tends to follow a nightly migration pattern that brings the organism to shallower waters at night, perfect for the spinner dolphin searching for a midnight snack. If needed, spinner dolphins will pod together in order to dive deeper for food as a form of defense against predators, such as sharks.

Spinner dolphins have a polyandrous mating system, meaning that a female spinner dolphin mates with multiple males throughout the course of the season. The spinner dolphins do mate seasonally; however, the time frame in which they mate depends on their geographic location. For example, eastern spinner dolphins mate in the early summer while spinner dolphins further north mate throughout July and August.

The calves are born after approximately 11 months. The mother will nurse the calves for as long as 2 years after they are born; however, a female will only give birth to one calve about every 3 years. 

Interestingly, mating behavior can also be exhibited between two male spinner dolphins, obviously without the end result of offspring. There is no evidence to suggest that mating behavior has occurred between two females.

The spinner dolphin gets its name from its unique behavior of jumping out of the ocean (sometimes 10 feet in the air!) and quickly spinning before diving back in. They can complete as many as 6 spins before re-entering the water below and have been observed leaping out of the water while spinning as many as 7 times in a row! 

In addition to their unique spinning and jumping capabilities, dolphins are also able to communicate through echolocation. They use their fins to slap the water’s surface in order to convey to other dolphins that there is danger or food nearby.