Hermit Crab (Coenobita clypeatus)
Experience Level: Beginner
Land Hermit Crabs
Did you know? Land Hermit Crabs eat both animal and plant matter. They are easily handled but can pinch if they feel threatened. They shed their outer skin (molt) in order to grow. After molting, crabs are extremely vulnerable because their bodies are soft and pliable. Isolate them from other crabs during this time. Dropping them onto a hard surface can cause severe injuries or death.
Step 1Choosing an Aquarium
(A) Aquariums or other plastic or glass habitats can be used to house Hermit Crabs.
• A good rule of thumb is five gallons (20 L) of habitat space for every two crabs.
• Hermit Crabs are social and do well in groups.
• An appropriate aquarium stand will safely support the weight of your aquarium or terrarium.
• Locate your aquarium in a low-traffic area, away from direct sunlight and drafts.
Hood and Light Fixture
(B) Place an aquarium hood with light fixtures on the aquarium to maintain humidity and prevent escape.
• The light should be on for 8-12 hours a day. Turn it on during the morning feeding, and off after the evening feeding, or use an automatic timer.
Step 2Heating and Humidity
Under-tank Heater and Thermometer
(C) Use a reptile terrarium thermometer to measure the temperature.
• Hermit Crabs require temperatures ranging between 70-75º F (21-24º C) during the day.
• Use an under-tank heater on one side of the habitat to maintain this temperature in cool environments.
• Be sure there is always at least 1" of substrate over the under-tank heater, if used, to protect the crabs from the heat.
(D) Use a reptile terrarium hygrometer to measure humidity.
• Habitat humidity should stay between 50-80%.
• Mist the habitat with dechlorinated water to maintain humidity level, as needed.
(E) Add a shallow water dish to help maintain humidity level and allow for full body soaking. Be sure water is not too deep and if you have both small and large crabs, place a natural sea sponge in the dish to help the smaller crabs climb out.
Step 3Substrate and Decor
(F) Use 1.5 lbs. (680 g) of aquarium gravel for every gallon (4 L) of tank capacity to make a 2-3" (5-8 cm) layer on the bottom of the aquarium. Rinse the gravel in a clean container before adding it to the aquarium (do not use soaps or detergents as they may be toxic).
• Alternatively, a 2-3" (5-8 cm) layer of fine reptile bark bedding can be used with Hermit Crabs to help maintain appropriate humidity.
• Hermit Crabs may burrow into the substrate to hide when they molt.
(G) Decorate the aquarium with artificial plants, as Hermit Crabs may eat live plants.
• Plastic plants can be used to create climbing areas for the Hermit Crabs.
Ornaments and Rocks
(H) Hiding places should be offered to provide a secure area as a retreat. Use ornaments and rocks that are designed for aquariums or terrariums to provide caves for sheltering Hermit Crabs.
• Hermit Crabs will need to switch into larger shells as they grow after each molt.
• Provide at least two larger extra shells of varying sizes for your crabs.
• Do not be alarmed if your crab changes its shell frequently.
Do not release Hermit Crabs or any other pet into the wild. They will not survive, but they may transmit diseases to the wild animals or otherwise be harmful to the environment.
Things to Watch For
• Decreased appetite or activity
• Excessive shedding of the skin Loss of claws or limbs
• Staying out of its shell
• Strong odor from inside of shell
If you notice any of the signs described above, speak with a PetSmart store associate or a veterinarian about the health of your pet.
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