Spinner dolphin (Stenella longirostris) is a small-sized dolphin and it is well-known for its acrobatic movements in the air. It spins its body 2 to 3 times while leaping itself into the air. Some other movements are slapping its tail, head and back on the surface. These dolphins tend to move around in schools (group name) of hundreds to thousands of individuals.
There are four subspecies of the spinner dolphin:
Eastern spinner dolphin
Central American spinner dolphin
Hawaiian spinner dolphin
Dwarf spinner dolphin
It is small in size and has slender body. The dorsal fin is triangle-shaped and it has an extended beaklike snout (called rostrum). The color of its dorsal is dark gray while the sides and underside are pale gray to white. There is a dark strip running down through its eye and toward the flipper. However, there is a lot of variation in its color.
They can grow from a size range of 5 to 7 feet in length and weigh around 130 to 169 pounds.
The spinner dolphin has a maximum lifespan of 20 years.
A female spinner dolphin reaches maturity at the age of 4 to 7 years while the male dolphins mature at around 7 to 10 years. The mother suckles her calf for about 1 to 2 years.
Spinner dolphins inhabit tropical and subtropical coastal and off-shore waters. In Hawaii, they are clustered along coastal bays but in other regions, they inhabit deep-water of the oceans. During the day, they tend to rest at shallow coastal bays but begin foraging for fish in the sunset.
The primary diet of these dolphins consists of deep-water squids, fish and family of prawns called sergestid shrimps. They can dive down to a depth of 650 to 984 feet in search of food.
The predators of the spinner dolphins are the short-finned pilot whale, the orca, the pygmy and false killer whales as well as sharks.
Other Name: Short-snorted dolphin