Dolphin megapod seen for the first time – in pictures

A rare glimpse of a megapod of spinner dolphins – where two superpods meet to socialise and mate Photograph: John Downer Productions

Spinner dolphins are often found cruising at a gentle speed of 5mph but occasionally, as seen here, they stampede off and can reach speeds of up to 25mph Photograph: John Downer Productions

Spy Dolphin captures the moment a dolphin corkscrews from the water. Spinner dolphins often have remoras (suckerfishes) attached to them. One theory behind their unique behaviour is that the remoras are a nuisance and the spinning helps to dislodge them Photograph: John Downer Productions

Spy Dolphin gets close to a dolphin spinning at the surface Photograph: John Downer Productions

Spy Dolphin captures a glimpse of the megapod beneath the surface Photograph: John Downer Productions

Spy Tuna gets into the centre of the megapod underwater Photograph: John Downer Productions

Spy Tuna views a superpod of over 1000 dolphins Photograph: John Downer Productions

Spinner dolphins continue to spin as the sun sets off the coast of Costa Rica Photograph: John Downer Productions