Guardian of the Mangroves – Overall Winner. Tanya Houppermans, Cuba. A curious American crocodile (Crocodylus acutus) swims right up to Tanya, at Gardens of the Queen (Jardines De La Reina), an archipelago off the coast of Cuba. It has been strictly protected since 1996, and is one of the most untouched marine ecosystems in the world. ‍ “The healthy population of American crocodiles is down to the pristine condition of the mangroves and I wanted to capture close ups of this gentle giant in its natural habitat. I hope this image can illustrate that protecting areas like this is so critical”. (Photo by Tanya Griffin Houppermans/Mangrove Photographer of the Year)

The NASA Extreme Environment Mission Operations (NEEMO) 21 mission began on July 21 as an international crew of aquanauts splashed down to the undersea Aquarius Reef Base, located 62 feet below the surface of the Atlantic Ocean in the Florida Keys National Marine Sanctuary. The NEEMO 21 crew will perform research both inside and outside the habitat during a 16-day simulated space mission. During simulated spacewalks carried out underwater, they will evaluate tools and mission operation techniques that could be used in future space missions, including journeys to Mars. (Photo by Karl Shreeves/NASA)

Lance Cpl. Blas Trevino of the 1st Battalion, 5th Marines, shouts out as he is rescued on a medevac helicopter from the U.S. Army's Task Force Lift “Dust Off”, Charlie Company 1-214 Aviation Regiment after he got shot in the stomach outside Sangin, in the Helmand Province of southern Afghanistan on June 11, 2011. The Army's 'Dust Off' crew needed two attempts to get him out, as they were fired upon and took five rounds of bullets into the tail of their aircraft. (Photo by Anja Niedringhaus/AP Photo/File)

“The giant clam, Tridacna gigas (known as pā’ua in Cook Islands Māori), is the largest living bivalve mollusc. T. gigas is one of the most endangered clam species. It was mentioned as early as 1825 in scientific reports. One of a number of large clam species native to the shallow coral reefs of the South Pacific and Indian oceans, they can weigh more than 200 kilograms (440 lb) measure as much as 120 cm (47 in) across, and have an average lifespan in the wild of 100 years or more”. – Wikipedia

Photo: Tridacna Gigas, or Giant Clams spew water as a traditional fisherman passes by a small sanctuary on January 23, 2004 near Bolinao in the Northern Philippines. The clams, prime builders for coral reefs and providing shelter for spawning fish and other marine life, are exposed by low tides in the sanctuary. Overfishing and pollution throughout the country are not only threatening food security, but are also starting to choke one of the few working clam sanctuaries in the world. (Photo by David Greedy/Getty Images)

It's that time of year again when dogs with unusually large heads, hairless bodies and other oddities compete to be the World's Ugliest Dog. This year's winner? A 2-year-old mutt named Peanut, whose wild white and brown hair, bulging eyes and protruding teeth belie his sweet, energetic personality. Peanut's owner, Holly Chandler of Greenville, North Carolina, says he was seriously burned as a puppy and she wants to use her pet to raise awareness about animal abuse. She plans to use the $1,500 prize to pay for other animals' veterinary bills. The contest, held at the Sonoma-Marin Fairgrounds in Petaluma, California, is in its 26 year. The dogs are scored by a three-judge panel in several categories, including special or unusual attributes, personality and natural ugliness.

“The frilled shark (Chlamydoselachus anguineus) is one of two extant species of shark in the family Chlamydoselachidae, with a wide but patchy distribution in the Atlantic and Pacific Oceans. This uncommon species is found over the outer continental shelf and upper continental slope, generally near the bottom though there is evidence of substantial upward movements. It has been caught as deep as 1,570 m (5,150 ft), whereas in Suruga Bay, Japan it is most common at depths of 50–200 m (160–660 ft). Exhibiting several “primitive” features, the frilled shark has often been termed a «living fossil»”. – Wikipedia

Photo: A 1.6 meter long Frill shark swims in a tank after being found by a fisherman at a bay in Numazu, on January 21, 2007 in Numazu, Japan. The frill shark, also known as a Frilled shark usually lives in waters of a depth of 600 meters and so it is very rare that this shark is found alive at sea-level. It's body shape and the number of gill are similar to fossils of sharks which lived 350,000,000 years ago. (Photo by Awashima Marine Park/Getty Images)

“David Doubilet (born 28 November 1946) is a well known underwater photographer known primarily for his work published in National Geographic Magazine. He was born in New York and started taking photos underwater at the young age of 12. He started with a Brownie Hawkeye in a rubber anesthesiologist's bag to keep the water out of the camera. During his summer holidays, he spent his time along the New Jersey coast. He later worked as a diver and photographer for the Sandy Hook Marine Laboratories in New Jersey. He also spent much time in the Caribbean. While a dive instructor in the Bahamas he found his motivation to capture the beauty of the sea and everything in it”. – Wikipedia. (Photo by David Doubilet/National Geographic)