Alex Mustard / Dugong (Dugong dugon) male and juvenile Golden trevally (Gnathanodon speciosus) swimming over Seagrass (Halophila stipulacea) meadow. Marsa Nabaa, Marsa Alam, Egypt.

Alex Mustard / Green turtle (Chelonia mydas) feeding on Seagrass (Halophila stipulacea), blowing sand out of nostrils, on sea floor. Marsa El Shouna, Marsa Alam, Egypt.

Alex Mustard / Green turtle (Chelonia mydas) resting on sea floor and two juvenile Golden trevally (Gnathanodon speciosus). Marsa El Shouna, Marsa Alam, Egypt.

Alex Mustard / Spinner dolphin (Stenella longirostris) pod socialising close to surface. Fury Shoal, Sataya Reef, Marsa Alam, Egypt.

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) shoal swimming with open mouths, filtering for zooplankton. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) mouth wide open as it swims through the water, filtering zoopankton with its gill rakers. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) shoal swimming with open mouths, filtering for zooplankton. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) with mouths wide open as they swim through the water, filtering zoopankton with their gill rakers. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Alex Mustard / Striped mackerel (Rastrelliger kanagurta) with mouths wide open as they swim through the water, filtering zoopankton with their gill rakers. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea

Alex Mustard / Red-spotted guard crab (Trapezia tigrina) in hard coral (Pocillopora sp.). Ras Torombo, Marsa Alam, Egypt. Red Sea

Alex Mustard / Honeycomb coral (Favia favus). Marsa Shouna, Marsa Alam, Egypt. Red Sea

Alex Mustard / Green turtle (Chelonia mydas) begins to swim back to the surface to breathe after feeding on seagrass. Marsa Shouna, Port Ghalib, Marsa Alam, Egypt. Red Sea