Decorator crab is the name given to many species of crabs of different species, belonging to the superfamily Majoidea, which like to use materials from the surrounding environment to disguise, or ward off, predators.

From spider crabs, mud crabs, moss crabs, to tooth crabs and arrow crabs, there are more than 700 different species of crabs belonging to the superfamily Majoidea – ornamental crabs. These crabs often create a camouflage to cover their bodies with a variety of “ornaments” that sometimes go beyond our imagination.

Ornamental crabs are crabs of several different species, belonging to the superfamily Majoidea, that use materials from their environment to hide or ward off predators. They decorate their bodies by sticking mostly sedentary animals and plants to their bodies to camouflage, poisonous creatures to ward off predators.

According to Marine Madness, most of these crabs use other marine life as “building materials”, which include corals, seaweed, sponges, sea fans, anemones, seagrass, and urchins. sea creatures, bryozoans & hydrozoans (locally endemic creatures often confused with algae or corals) and even other small crustaceans.

In 1889, William Bateson observed in detail how these crabs fix materials on their backs. He notes that if you deliberately remove their camouflage shell, immediately after being released, they will re-form a camouflage shell identical to the previous one.

However, using other creatures as camouflage does not mean killing them. On the contrary, they are linked together in a symbiotic, mutually beneficial relationship.

In nature, animals are under pressure to change to blend in with their environment or hide their appearance; Hunted animals thus evade predators and predators can attack without being detected.

The degree to which ornamental crabs are particular to their decorations was clearly demonstrated by research conducted in 1940 by the British zoologist and camouflage expert, Hugh Bamford Cott, who studied large spider crabs (Hyas araneus) in the Atlantic Ocean.

Reviewing studies carried out by different authors, Hultgren and Stachowicz show that some species are very specialized in their choice of camouflage. For example, Pelia tumida has only sponge decoration; Macropodia rostrata and Libinia dubia choose the toxic alga Dictyotahesiais in some places, while Inachus phalangium chooses the same alga for the most exposed body parts; and Stenocionops furcata chose the three-colored anemone Calliactis for its shell.

Cott moved a number of these ornamental crabs from their home off the coast of England to different locations, and found that each time they were placed in a new location, they immediately began to decorate. their camouflage using local materials – in fact, each crab adapts its camouflage to its environment.

It is found throughout the world’s oceans and seas. It can be seen at night because of the reflection of its eyes in the sea. This animal’s camouflage ability is so good that it is difficult to recognize them during the day.

In addition to using camouflage to protect themselves, some crabs have gone further with their use of decorations – using them to enhance their defenses in other ways. One example is the use of sea anemones, sea urchins and hydrozoans, all of which can inflict a nasty sting on any potential predators if they get too close. On the other hand, consuming poisonous seaweeds can leave an unpleasant (and potentially fatal) taste in the mouth of anyone who dares to risk attacking them.

In fact, the lifespan of these crabs has not yet been specifically estimated.

Furthermore, some species also know how to take advantage of their camouflage to attack. A good example is the boxer crab (Lybia tessellata), also known as the pom-pom crab, which attaches anemones and sea urchins to its claws and uses them as weapons.

There are about 700 species of ornamental crabs. Some crab species include Acanthonyx dentatus, Macropodia rostrata, Oregonia gracilis, Libinia emarginata, Achaeus spinosus and Camposcia retusa.

If provoked or attacked by a predator, they will threaten the predator and try to stop it by waving their anemones around, their tentacles fully equipped with cnidocytes (stinging cells). .

The total population size of these crabs is unknown.

Other ornamental crabs even take advantage of the aquatic species Hydrichthella epigorgia, which, like coral, is made up of countless tiny polyps that work together as a collective organism. However, unlike most hydrozoans, the polyps of this species do not have feeding tentacles but instead have sticky polyps that capture microscopic food and slowly transfer it into the “mouth”. Some particularly cunning species have taken advantage of this feature and attached them to their claws to create a pair of sticky and effective fishing rods.