When you venture to the pet store to buy hermit crabs, you may notice that there is a wide variety in the types of regular or painted hermit crab shells available. There is also some debate as to whether or not the painted shell variety is healthy for crabs.
First of all, it’s important to understand a bit of the background as to why specifically the hermit crab has many shells throughout its life, which it wasn’t born with. Hatched from eggs in the ocean, these crabs have no shell, but only an exoskeleton, and they head to shore to look to “borrow” the discarded shell of a typical sea snail. This is to ward off lurking predators who want to make them lunch.
Note that in the wild, these crabs select natural shells that can come in a variety of shapes, sizes, and textures. Natural shells range from being rough to smooth like glass, to being more of a nautilus shape or oval in shape, and many shell openings in between. Hermit crabs shed naturally, and each time they shed their exoskeleton in the process, they need a new, larger shell. It is at this point that they trade the shells for something bigger and better. The shells that hermit crabs find in nature are not painted with acrylic paints, nor do they have any type of exterior decoration attached.
We find it very cute and fun to “customize” our hermit crab pets when we buy them at the pet store, selecting those shells that best suit our personality. This could include custom colors, patterns, and designs, or even shells that reflect various sports or superheroes. However, it has been concluded in certain studies that painted crab shells may actually cause physical harm to the health of captive crabs.
As the crabs walk around and go about their lives, there is a chance that the crabs will consume specks or bits of acrylic paint. Also, such paint chips can become a major irritant inside the crab’s shell. Craft paints may say they are non-toxic, but this is based on human ingestion and not consumption by a crab. Often times, the paint on the internal parts of the case is also wet for an extended period of time; therefore, when a crab moults or outgrows its shell, it cannot move to another shell as it is trapped inside its shell permanently. This can easily result in the death of your crab.
Painted hermit crab shells sometimes also have external crafts attached to their shells to make them cuter or more attractive to potential owners. The most common craft is “Google eyes” that are attached to the top of the shell. If the craft slips out of your crab’s cage, this can also create a significant health hazard for your crabs, or at the very least, an irritant if it becomes lodged within its shell.
It’s very hard not to choose the “bright and shiny object”, but it’s important to be more concerned with the health and happiness of our crabs in order to provide them with the most organic resources available. This includes choosing natural crab shells over painted hermit crab shells.