A Spinner Dolphin’s fin (Stenella longirostris) rises above the waves, before merging back into the ocean, off Kalpitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

Around sunset, Spinner Dolphins gather into groups which may contain more than a thousand individuals.

Spinner dolphins are carnivores. They eat fish and squid. At night, they travel out to deeper water to hunt. In the morning, they move back to shallow water to rest, play, and watch for predators, such as sharks. (a)

Fossil hunters have discovered the remains of the earliest ancestor of the modern whale; a small deer-like animal (named Indohyus) that waded in lagoons and lived on vegetation around 50 million years ago. (b)

This landmark finding represents a long-sought “missing link” in a 10 million-year journey, where ancient land mammals gradually evolved into modern cetaceans, a group that includes whales, dolphins and porpoises. (b)

Mimicking the shiny scales of many fish, the Spinner Dolphin’s tail has a smooth skin to reflect the light and disorientate its predators, such as sharks or the Orcas.

This photograph is a clear reflection of the mirror effect of the skin of a Spinner Dolphin (Stenella longirostris) disappearing into the depths, off Kalpitiya Peninsula, Wayamba (North Western Province), Sri Lanka. And surrounded by circles and droplets merging into the ocean blue.

Long-snouted Spinner Dolphin’s Tail (Stenella longirostris) diving for the next opportunity, off Kalpitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A Spinner Dolphin Pod (Stenella longirostris) with youngster off Kalpitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

If you are lucky, you can see hundreds of these dolphins jumping out of the ocean for almost as far as the horizon. The fisherman may try to follow them, as they know where the fish are, but they will never be able to keep up. No nets are allowed, which is why they are using rods.

Spinner Dolphin (Stenella longirostris) off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

Large Spinner Dolphin (Stenella longirostris) off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

Pod of Long-snouted Spinner Dolphin (Stenella longirostris) off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A pair of Spinner Dolphins (Stenella longirostris) off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

Spinner Dolphin (Stenella longirostris) leaping & spinning off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka. It is not known why they jump and spin. It may be for fun, or even to dislodge parasites.

Three Spinner Dolphins (Stenella longirostris) in a row off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

Spinner Dolphin Pod (Stenella longirostris) off Kalpitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A young Spinner Dolphin (Stenella longirostris) leaping & spinning off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A Spinner Dolphin (Stenella longirostris) leaping & spinning off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A Spinner Dolphin (Stenella longirostris) leaping & spinning off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A Spinner Dolphin (Stenella longirostris) making a spectacular leap & spinning off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A Spinner Dolphin (Stenella longirostris) making a spectacular leap & spinning off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A Spinner Dolphin (Stenella longirostris) making a perfect diving finish off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

A multitude of Spinner Dolphin fins (Stenella longirostris) off Kalapitiya Peninsula, Wayamba (North Western Province), Sri Lanka.

Spinner Dolphin (Stenella longirostris) off Kalpitiya at sunset, when they gather to go night hunting in the open sea. Wayamba (North Western Province), Sri Lanka.