Decorator Crabs
Video Below
Many species of crabs decorate themselves. Two of those are the sponge crab and the decorator crab. The sponge crab often shapes the sponge to fit over a large part of their carapace, or hard exoskeleton and decorator crabs have hooked hairs all over their carapace that act like Velcro to hold any sort of decoration in place. What they wear depends on the species of crab.
Decorator crabs are like underwater artists
They use live sea sponges to decorate their shells and protect themselves. Using their special claws, these crabs carefully cut small pieces of sponge and stick them onto their shells. The sponge stays alive and continues to filter-feed, just like it would if it were still attached to the reef.
Unlike other crabs that rely on hard shells, decorator crabs have a more fashionable way of staying safe – they wear live sea sponges. This not only helps them avoid being caught by predators like fish, octopus, and other crabs but also adds a touch of chemical defense, as the live sponges release substances that keep threats at bay.
Teamwork
The teamwork between the crab and the sponge is called a symbiotic relationship. While it benefits the decorator crab a lot, we’re not entirely sure about the advantages the sponge gets. These crabs are not picky about the type of sponge they use – they like sponges of various shapes and colors. The most important thing is that the sponge fits nicely on the crab’s back.
Even though they are common, spotting them is tricky because they are skilled at hiding with their camouflage, and they usually come out at night.
Other Crabs
Other sea creatures, like hermit crabs, also use things like seaweed and shells to hide on the ocean floor. Despite knowing that hiding is helpful, it is still unknown why decorator crabs choose specific sponges. It’s a mystery, but we do know that both the crab and the sponge benefit from their partnership, helping each other stay safe and well-fed.