BM_HCwhale_shark by Hayley Coyle  THIS is the moment a brave underwater photographer captured a 40-foot whale shark feeding thousands of plankton through its gaping 1.5 metre wide mouth. The extraordinary image was taken about 20 miles north of the Mexican island of Isla Mujeres where hundreds of the giant fish flock for an annual feeding frenzy. Whale sharks, the biggest fish in the sea, have up to 350 rows of teeth but are docile creatures and not a threat to humans. Avid underwater photographer Ellen Cuylaerts, 43, took these pictures this month but said the whales aggregate in that area from mid May until September every year. According to Ms Cuylaerts, whose day job is working as an historian, the annual food forage was discovered about nine years ago after fisherman began to recognise the sharks’ distinctive dorsal fin gliding through the water. But what made this year’s feeding spectacle even more special was the influx of Manta rays joining the sharks, she said. Ms Cuylaerts continued: “The contrast between the feeding whale sharks at the surface and the feeding Mantas dancing below was a pure joy for the eye. “When some whale sharks go deeper some Mantas come to the surface and start barrel rolling or swimming with their white bellies at the surface. “With a wingspan of 3 to 4 metres they're big but still tiny next to the 12 to 17 metre whale sharks.” Some conservationists argue that swimming with the whale sharks and photographing them could interfere with their feeding. But Ms Cuylaerts insists measures are put in place to prevent this from becoming a problem. She said: “Dive operators that take you there are only allowed to bring two people in the water at the time and all encounters are on snorkel  - no diving. “Also photographers or videographers are not allowed to use strobes or lights and touching the animals is strictly forbidden.” Ms Cuylaerts, who is Belgian but who now lives in the Cayman Islands with her two teenage children, also explained that boats are starting to use prop guards on their vessels, which prevent the sharks from being injured by engine propellers. She said one the most challenging parts of a shoot is that even though the sharks seem to leisurely drift through the water, they are actually quite fast so it is very difficult to get the snap you want while holding your breath for minutes at a time. Avoiding a nasty but undeliberate “tail slap” is another problem apparently. Ms Cuylaerts added: “One time I couldn't avoid the tail of a second whale shark while I was taking a picture of another one, and the tail hit my shins. “It’s very hard, not like a fish tail you would expect, more like a brick wall!” ENDS