Image of a Sea Anemone with permission from Petr VodickaImage of cluster of Sea Anemonies, with permission from Brocken Inglory



          One of the very first things people notice when looking at a Spotted Porcelain Crab is the beautiful coloration and unique pattern of spots on the body and legs. Image of the Spotted Porcelain Crab hiding within the tentacles of the sea anemone, from Wikimedia Commons, with permission from Steve ChildsThe Spotted Porcelain Crab composition is made up of an orange, white body with deep brilliant red spots sometimes outlined in violet. As with all other organisms, the coloring of the Spotted Porcelain Crab is used for a special purpose. This organism mainly uses the coloration as a camouflage technique. Alongside the unique coloration, the amonefish (also referred to as the Spotted Porcelain Crab) are considered to have a protective mucous coat that acts as “chemical camouflage” or “macromolecular mimicry” preventing “not-self” recognition by the sea anemone (Mebs, 2009). Not only is this mucous recognized by the sea anemone giving it a positive chemical message, but it also sends a message to surrounding predators that if consumed, the Spotted Porcelain Crab will taste very bad.

         Along with the camouflage technique, the Spotted Porcelain also has a very dense exoskeleton. With creating any structure of an organism, it takes a tremendous amount of energy, time and nutrients. The two main nutrients that make up the exoskeleton of the Spotted Porcelain Crab are proteins called chitin and calcium. The main reason for a protective exoskeleton is to provide the living organism with a shield, making it hard for other organisms to consume or harm it. The exoskeleton grows with the Spotted Porcelain Crab through everyday activities, but periodically the organism has to experience ecdysis, or molting. Instead of finding a new shell to burrow into, such as some crabs, the Spotted Porcelain Crab has grown a whole new soft exoskeleton underneath the old one. When the time is right, a large crack will appear along the back side of the Spotted Porcelain Crab, allowing the crab to push through the crack, freeing itself from the old exoskeleton (Shedd Aquarium, 2001). Although the Spotted Porcelain Crab is protected by the sea anemone, it has to do the whole process of ecdysis as fast as it can. Predators surrounding the sea anemone will target the Spotted Porcelain Crab during ecdysis because it is most vulnerable, and if consumed when it has a soft exoskeleton, it will not take as much energy to break it down into edible pieces. Overtime, the new, fresh exoskeleton will become harder and more ridged. The ridges of the exoskeleton aid in muscle attachment. With the new and improved exoskeleton, it gives the Spotted Porcelain Crab the same protection as before, with enough room to continue growing. 


          Another adaptation that sets the Spotted Porcelain Crab apart from the others is the last pair of legs. The last pair of legs are noticeably smaller than the others, and are often times hidden within the body cavity. This makes the Spotted Porcelain Crab appear to have 6 walking legs and 2 claws, while many other typical crabs have 8 noticeable legs (British Broadcasting Corporation, 2010). The legs do not do the Spotted Porcelain Crab great advances, since it is a filter feeder. It does not have to search very hard for food, because with the protection of the sea anemone, it can relax and feed as needed. 


          There are multiple structural factors that limit the Spotted Porcelain Crab from functioning in the appropriate environment. One factor being the actual size of the Spotted Porcelain Crab. Due to the fact that it is not much larger than a Christmas tree light bulb, it is limited to traveling in far distances. To accommodate for this limitation, the Spotted Porcelain Crab stays within the protection of the sea anemone. Another limiting factor is the bright coloration. If the Spotted Porcelain Crab were to go outside the safe perimeters of the sea anemone, it would be picked up by predators in an instant. Outside the sea anemone, there are minimal organisms that the Spotted Porcelain Crab could blend in with.


 Next, take a look at how the Spotted Porcelain Crab interacts with others within the same habitat by clicking here.

Click here if you would rather return home.