Gigantic channel crab is no match for a hungry octopus

The ocean is a beautiful place, full of colour and wonder. The animals are fascinating, graceful, and unique in ways that we are barely beginning to understand. But the ocean is a very unforgiving place as well and all animals are constantly struggling for survival in a world where they are the predator one minute and the prey the next. It's a delicate balance that can change in an instant and the creatures in the ocean need to always be watching for danger.

This world changes abruptly when the sun goes down. Darkness brings with it a change that come on as rapidly as the light fades. Creatures with keener night vison and a sharper sense of smell now become the dangerous ones as the fish that swam freely by day must find a place to hide. The channel clinging crab is one of the larger crab species in the Caribbean. It emerges from its lair in the coral to feed on decaying matter and algae. Under the cover of darkness, its camouflage colour and rough surface allows it to blend in nearly perfectly with the rocks and coral around it. It uses long claws to pick at food and place the small bits in its mouth. These crabs are very beneficial to the reef, keeping algae in check and cleaning up rotting debris.

But another animal also comes alive at night and it is one of nature's most perfectly designed predators. The most intelligent invertebrate on the planet, the octopus has a capacity for learning, problem solving, and memory that surpass what we once believed impossible in animals. They have sharp vision and one of the most developed tactile senses in the animal kingdom. Each tentacle is capable of smell and its eight arms work independently to find and subdue prey with complete effectiveness. Possessing incredible strength and unsurpassed flexibility, these animals are formidable. They are able to overpower animals much larger than themselves with ease.

Crevices and hiding places in the coral become more prison than protection when the octopus arrives. When it sense an animal tucked into a tight spot, it extends its arms inward, exploring for the hiding creature as it covers the escape route with its mantel. The food can either try to flee and be captured in the widening umbrella, or it can remain hidden and be dragged out by the powerful arms. In most cases, there will be no escape once the octopus has found its food.

This channel clinging crab has been found in the open and the octopus has seized it, one claw at a time. The powerful beak can pierce the armour of the crab but the octopus prefers to attack the vulnerable underside. It systematically pins each of the crab's claws and works the crab around so that the softer shell of the belly is in position for the razor sharp beak of the octopus. Once this is accomplished, the crab has only moments to live. It struggles valiantly, trying to deter the octopus with a claw and trying to pull itself into the coral. But none of these efforts have any effect on the octopus and the battle is over in less than ten minutes.

The octopus will find a quiet spot to devour the crab in safety. It knows that while it eats the large crab, many creatures roam the water and the reef that would like to eat an octopus. Sharks, eels, and barracuda also patrol these waters and many of them also hunt at night with keen senses of their own. A large shark or moray will devour even the biggest octopus if it is caught unaware.

The battle for survival is a complex one in this mysterious domain and the struggle to survive will continue until daylight, and beyond.