A "once-in-a-life-time" stingray encounter on Western Australia's Ningaloo Reef is one of many stunning photos commended in the Open competition of this years Sony World Photography Awards.
Photographer Alex Kydd submitted the captivating photo titled "A Fever of Cownose Rays", which he caught while freediving in what is one of the world's largest coral reefs.
Kydd described it as a "rare encounter", where the rays were "circling and rubbing together in a behaviour that is not fully understood".
The annual awards, run by the World Photography Organisation, shortlisted more than 100 photographers in this years competition and crowned winners across 10 categories, from architecture to the natural world and wildlife.
Photographer Muriel Vekemans' dramatic image of a greyhound stirring up the sandy track as it finished training for a race was also among those shortlisted.
Vekemans, from Belgium, said "as it headed to the finish, I was waiting for it with my face in the sand."
Snapper Trung Pham Huy's photo, highlighting the incredible efforts put into water lily harvesting in Vietnam, was also shortlisted.
Several women are seen torso-deep in the Mekong River collecting the beautiful purple-flowered plants, which are then washed and wrapped before being sent off to market.
Category winners of this year's competition took home the latest digital imaging equipment from Sony and will go on to compete for the prestigious Open Photographer of the Year and a $US5,000 ($A7,960) prize.
The overall Open winner will be announced on June 9 on the World Photography Organisation and Sony's online platforms.