Hermit Crab Care

HERMIT CRAB CARE SHEET

FACTS:

How long will my Hermit Crab live? They can live for 10-15 years

How big will my Hermit Crab grow? They will grow 1-8cm

What does a Hermit Crab eat? Hermit crab food, with fruit and vegetables

TANK SIZE AND TYPE: 

The general rule of thumb is 38 litres per small-medium crab and 56 litres per medium-large crab. Due to hermit crab's social nature, they must be kept in at least pairs. This means the bare minimum crabitat size is 75-115 litres. Bigger is always better. 

Your crabitat must have a secure lid as hermit crabs are well known for their excellent climbing abilities and great escapes. Glass or plexiglass lids work best as they hold in humidity and will not mould like wood might. 

Fish Tanks work best for crabitats however reptile-style terrariums can also work well with a few modifications such as restricting ventilation and a base that allows for deep enough substrate.

SUBSTRATE: 

Hermit crabs require a substrate mixture of sand and coconut coir (also known as coir peat / coco peat / coconut fibre / eco earth) which needs to be at least 15-25 cm deep or at least 3 times the size of your biggest crab for larger crabs. The ratio of each should be 5:1 sand to coconut coir

LIGHTING: 

Hermit crabs require a 12-hour day-night cycle. This is achieved by turning their lighting off for 12 hours during the night and on for 12 hours during the day. Although UVB is not required for hermit crabs, they do still benefit from it, so it is worth considering providing UVB. If you do choose to provide UVB ensure it is a 5.0/ natural or tropical type, not a 10.0/desert type.

HEAT: 

The optimal temperature for Aussie hermit crabs is between 26-32°C. If the temperature drops below 20°C hermit crabs may go into a state of unnatural hibernation. However, they do this as a very last resort to sustain their life. Sadly, it usually results in casualties.

The temperature is maintained by using a heat mat/s or heat cord placed on the back and/or sides of your crabitat. They must be placed above the substrate layer to heat the air, not the substrate. The heat mat should cover at least 2/3 of the length of your tank and be no less than 25 watts otherwise, it will not have the power to heat your tank. The higher the watt the better. 

Heat lamps must not be used as they dry up the enclosure and their heat is more directed at one spot. Ensure any heat-emitting device is hooked up to a reliable thermostat. This will turn your heating device on and off as needed and prevent it from overheating and causing a fire.

HUMIDITY: 

The humidity needs to be maintained at approximately 70-85%. You should have a hygrometer in your tank, so you are able to observe the humidity in your tank easily. The hygrometer should not be resting on the substrate and we’d recommend digital rather than analogue as they’re more accurate and reliable. Hermit crabs breathe through modified gills, not lungs which is why humidity is so important. If the humidity is too low your hermit crabs will not be able to breathe well, however, if it's too high for too long this may cause a flood in your tank. The humidity can be raised by ensuring the tank is completely sealed adding damp sphagnum moss, adding live plants, adding bubblers to your crab's pools and situating the pools close to the heat source. It can be decreased by doing the opposite and wiping condensation off the glass. Please do not use sponges as they harbour bacteria and don't benefit your crabs. 

You should also have a thermometer in your tank, so you are able to easily observe the temperature of your tank. We’d also recommend the thermometer be digital rather than analogue as they are more accurate and reliable. 

WATER:

Your hermit crabs will require access to both fresh and saltwater which needs to be deep enough that the crab can fully submerge itself and its shell. This is very important as Hermit Crabs store brackish water in their shell to help them breathe and ensure they don't dry out. 

Your crab's fresh and saltwater will need to be treated with a water conditioner to dechlorinate your tap water and remove other nasties such as heavy metals and other contaminants.

You will then need to add marine-grade salt to your crab's designated saltwater pool. Please do not use table/cooking salt. It's not the same thing and will likely kill your crabs. Aquarium salt can be used however it doesn't contain many minerals which are beneficial to your crabs. Please refer to the instructions on the bottle/packet.

It is recommended to add bubblers to your pool to create some movement in the water. Stagnant water will need to be replaced daily as a biofilm will form across the top of the water and harbour bacteria. Pools with bubblers can be changed every 2-3 days. For larger pools, you can use small fish tanks. These will require a filter and heater but only need weekly-biweekly 50% water changes. 

Make sure your crabs have easy access in and out of the water. Please do not use sponges as they harbour bacteria and don't benefit your crabs. Hermit crabs love to 'swim' and although they cannot breathe underwater, they can hold their breath for over an hour! Try and make your bridges close to the side of the container so they can't crawl underneath. When they want to get out, they tend to crawl to the edge of the water. If they happen to run into the ramp while they're walking to the edge, then great but if they walk to the end without the ramp they'll just continue walking the parameter of the container ultimately walking underneath the ramp and not finding it.

SHELLS: 

You will need to provide your hermit crabs with at least 6 appropriately sized shells each. These shells should be slightly bigger than the one they are currently in.

FEEDING:

Hermit crabs are opportunistic, scavenging omnivores that feed upon a wide variety of foods such as fruit, vegetables, insects and even carrion.

In captivity, food should be always available to hermit crabs and placed in shallow dishes to prevent fouling of the tank.

A dry commercial hermit crab flake or pellet can be used as the primary source of food. Fresh fruits and vegetables such as apple, carrot, kale and banana should be offered 2-3 times per week. Hermit crabs will also readily accept dead insects such as dried mealworms, and crickets which can be coated with a calcium and vitamin supplement. Cuttlefish is also a good source of calcium.

SHOPPING:

• Enclosure; 75-115 litres. Bigger is always better
• Substrate, sand and coco peat
• Large water bowls/containers (x2)
• Food bowl
• Hides
• Thermometer
• Hygrometer
• Climbing branches
• Ornaments
• Heat mat 25w
• Misting water bottle
• Bathing salt
• Hermit crab food
• Fruit and veg