Gigantic channel-clinging crabs explore reef under cover of darkness

Channel clinging crabs are enormous creatures that come out in the night to wander over the coral and rocks. They can weigh up to 2kg (4.4lbs) and have a span of more that 60cm (2.5 feet) with claws outstretched. They are a species of spider crab and they are the largest crabs in the Caribbean.

These crabs can be seen on rare occasions during the day as they hide in coral ledges and caves. They come out on the reef at night to feed on carrion and algae. This is essential to the health of the reef as they keep the algae from overwhelming and killing the coral. They also clean up the rotting meat and decaying flesh that would also be detrimental to the health of the reef.

These scuba divers encountered this giant crab walking over the coral in search of food as they explored the reef on a night dive. The reef comes alive under the cover of darkness as nocturnal animals venture out in search of a meal.

The animals that dominate this realm in the dark often have keener night vision or an enhanced sense of smell, allowing them to hunt and find food more effectively. Many animals take shelter as the sun goes down as they are well aware that they are at a disadvantage in the dark. The line between predator and prey is a fine one and it can change quickly as night falls.

These large crabs are well protected by their spiny limbs and hard shells. A full grown crab like this one is unafraid of most fish, but sharks, octopus and even large moray eels are able to crack their shells easily.

For these scuba divers, the sight of one of these magnificent and unusual creatures made for a memorable dive.