The Diet of Hermit Crabs

Feeding your hermit crabs is an important part of keeping them happy and healthy. Hermit crabs are scavengers, as such, they have evolved to have specific dietary needs.

Unlike some species of crabs, it is impossible for a Hermit crab to get everything it needs from a single food source. According to experiments and studies, Hermit crabs enjoy trying new foods and can get bored with eating the same meals everyday.

It has been said that you should give your Hermit crab a new, or different food each time you feed them. This is a little extreme and isn't always possible, but they will appreciate having something different once in awhile.

Hermit Crab Dietary Needs

In order to be sure your Hermit crab's dietary needs are met, you need to know which vitamins and nutrients are important to hermit crab health. Most commercial crab foods sold for hermit crabs are lacking in important nutrients, or include things that may be toxic to your crab. When choosing food for your Hermit crab, you should keep their specific needs in mind. Always read the ingredients on commercial foods, flashy advertising isn't beneficial to your crab.

Crucial Parts of a Hermit Crab Diet

If you want your Hermit crabs to be healthy, their food should contain balanced and specific amounts of all nutrients, such as: carbohydrates, calcium, protein, fats, astaxanthin just like people do.

Of course, if you decide to dig even deeper, you will find that some pro-keepers advise to take a look at Beta Carotene, Tannin, Zeaxanthin, Carbohydrates as well. Although, this is a good advice, I am not going to overwhelm you with these details. The point is, I hardly believe that majority of Hermit crab keepers will be so picky about it. In addition, all these nutrients usually come along with the main ones. Note: When was the last time you check for all these ingredients that I listed for your own food? So, let’s be realists here.

• Astaxanthin

Astaxanthin is a pigment molecule that is commonly found in red foods. It contributes to the color in a Hermit crab's exoskeleton and helps support healthy organs and bodily functions. Astaxanthin can be found in krill, plankton, red seaweed, shrimp, etc. Note: Astaxanthin is very important to crabs, which have a hard time synthesizing pigments on their own. It enhances whatever natural color already exists. You can read more about it in my article “How to Enhance Shrimp Color?”.

• Calcium

As with shrimp and snail, Calcium is crucial to a Hermit crab's exoskeleton, cellular function and overall health. Calcium can be found in kale, broccoli, spinach, cuttlebone, eggshell, exoskeletons, figs, nuts, wonder shells, oyster shells, seaweed, seeds, insects, etc. You can read more about it in my article “How to Supplement Shrimp and Snails with Calcium”.

• Carbohydrates

Carbs are a biomolecule that is processed into sugar by all living things. Carbs store and deliver energy, they also make up a portion of chitin in a hermit crab's exoskeleton. Sources of good crabs are fruit, grains, honey, noodles, rice, seaweed, and dried vegetables.

• Protein

Protein is a compound made up of amino acids. It contributes to exoskeleton and soft tissue health. Protein is also crucial to the crabs ability to process carbohydrates and fats. Protein can be found in alfalfa, broccoli, crab, egg whites, freeze dried bloodworm, freeze dried plankton. Crickets, mealworms, kale, beef, chicken, turkey, rice, shrimp, spinach and tuna.

• Fats

Fats are molecules that store energy and can be solid (fat), or liquid (oil). Fat is used to make cell membranes and process vitamins. Fat can be found in almonds, coconut, egg yolk, meat, pumpkin seeds, salmon, sunflower seeds and walnuts. Fat can also be found in many oils such as canola oil, coconut oil and palm oil. *When using oils in your hermit crabs diet is is best to choose cold-pressed oils.

Commercial Hermit Crab Food

I would like to start off by saying that many Hermit crabs keepers are overzealous here. They say that many commercial crab foods contain preservatives, additives and pesticides that can be harmful to Hermit crabs. So, they do not advise using them at all. Well, perhaps I will say blasphemy here but Hermit crabs are scavengers! In the wild, they will eat whatever they find and it will not be a top quality restaurant food.

Therefore, if you do not have the time, or resources to provide a home-made diet plan for your crabs. If this is the case for you, don't worry. There are some relatively safe commercial foods available for Hermit crabs.

Important: Ideally, I do agree that even safe commercial Hermit crab food should not be a daily occurrence. However, it can be a temporary substitution of regular food (or good addition to regular food).

Some of the most popular commercial hermit crab foods (for good reason) are:

• Hikari Bio-Pure Frozen Foods
• Hikari Bio-Pure Freeze Dried Foods
• Zoo Med Hermit Crab Fruit-Salad All Natural Fruit Treat
• Zoo Med Hermit Crab Peanut Crunchies
• Fluker's 1.2-Ounce Freeze Dried Crickets
• Fluker's Premium Pellet Diet - Food for Hermit Crabs
• HBH Pisces Pros Variety Bites Hermit Crab Food

Some of these are marketed as treats, however, all of them can be used as a healthy part of your crab's daily diet.

I will repeat it once again, when using commercial foods it is always a good idea to supplement your Hermit crab's diet with fresh fruits and vegetables, or meat whenever possible. Even if you give them just an apple your Hermit crabs will be super happy!

Avoid feeding your Hermit crabs any foods containing:

• EQ – Ethoxyquin
• Copper Sulfate*(read below!)
• BHT – Butylhydroxytoluene
• Artificial Color
• By-products
• Ferrous Sulfate
• Magnesium Oxide
• Sodium Chloride
• Zinc Oxide
• Zeolite

Copper and Hermit Crabs

Absolutely everywhere you will see people saying that copper will kill your Hermit crabs. Avoid everything that contains copper, etc. Do not give them food with copper. Well, I do not think that this is that simple! To understand the problem we need to look at Hermit crab anatomy. Copper (Cu) is an essential part of hemocyanin. For example, human body needs iron for oxygen delivery, while Hermit crabs use hemocyanin as the oxygen-carrying pigment. Basically, this is their analogous role to hemoglobin in the blood system.

Therefore, I have some serious doubts that if we completely deprive them of copper, Hermit crabs will benefit of it. I am not saying that copper is safe. Of course, not. Copper is toxic to Hermit crabs when it exceeds the limits.

Now you can ask me – what is the safe level? Frankly saying, I do not know. I have not found a single study about it. However, if you check out nutrition value of apple, kale, zucchini, cucumber, spinach, etc. – almost everything contains copper! Therefore, I do not thing that those tiny doses in commercial food, will make a difference. Note: Shrimp keepers are also afraid of copper. However, in my research you can see another side of the coin. How Copper Affects Dwarf Shrimp

Feeding Your Hermit Crab a Homemade Diet

Preparing your Hermit crab's food yourself is the best way to control exactly what your Hermit crab is ingesting. There is no specific guide, or meal plan for feeding hermit crabs, so you will have the freedom to explore options.

If you choose to make your own hermit crab food you just need to remember to keep the meals balanced and include each food group:

1. Meat, Invertebrates, Insects and Fish
2. Fruits, Nuts, Seeds, Grains and Vegetables
3. Plants and Trees
4. Other Foods and Things Your Hermit Crab Will Enjoy

Meat, Invertebrates, Insects and Fish

Safe meats, insects, invertebrates and fish your Hermit crab will enjoy are:

• Beef (raw, or cooked)
• Cuttlefish
• Krill
• Bloodworms
• Deer
• Liver
• Chicken (cooked, smash the bones)
• Duck
• Lobster (crush the exoskeleton)
• Caribou
• Eggs (including shells)
• Locusts
• Catfish
• Elk
• Mealworms
• Clams
• Cockroaches
• Moose
• Cod
• Flounder*Grasshoppers (dead, or freeze dried)
• Mussels
• Crickets
• Halibut
• Octopus
• Plankton
• Sardines (packed in water, no salt!)
• Trout
• Pork (no ham)
• Shrimp
• Turkey
• Salmon
• Snails
• Worms

Note: Hermit crabs love meat. Actually, they prefer it raw over cooked. Also keep in mind that, on the one hand, cooked meat will not have any parasites. On the other, it will spoil faster in the tank.

Fruits, Nuts, Seeds, Grains and Vegetables

Safe fruits, nuts, seeds, grains and vegetables your Hermit crabs will enjoy.

• Acorns
• Cabbage (all kinds)
• Coconuts (love it)
• Alfalfa
• Cantaloupe
• Grapes
• Almonds
• Carrots (including tops)Cashews (no salt)
• Green beans
• Apples (love it)
• Celery
• Honeydew
• Avocado
• Chard
• Melon
• Bamboo
• Cereal (unsweetened whole grain)
• Kale
• Banana
• Cherry (Fruit and wood)
• Kelp
• Beans
• Chestnuts
• Kiwi
• Beets (whole plant)
• Clover
• Lentils
• Bell Peppers
• Coconut (meat, oil, water and shell)
• Lima
• Blackberries
• Collards
• Beans
• Blueberries
• Corn (on the cob is fine)
• Macadamia nuts
• Broccoli
• Crab apple
• Mango
• Brown Rice
• Cucumber
• Millet
• Brussel Sprouts
• Eggplant
• Mushrooms (food grade only)
• Okra
• Pears
• Pumpkin (entire plant is safe)
• Olives
• Peas
• Radish
• Papaya
• Pecans
• Raspberries
• Peaches
• Pickles
• Rolled oats
• Peanuts (and shells)
• Potato (no green parts)
• Sea grasses
• Seaweed
• Squash
• Timothy hay
• Soy
• Strawberries
• Wheat
• Spinach
• Sunflower seeds
• Turnips
• Sprouts
• Sweet potato
• Walnuts
• Watermelon
• Wild Rice
• Zucchini

Plants and Trees

Safe plants and trees that can be used in your hermit crab's diet

• Ash Wood
• Buttercup (only when dried)
• Burning Bush
• Birch Wood
• Carnation Flowers
• Maple leaves and branches
• Oak wood (love it)
• Dandelion (flowers, leaves and roots)
• Chia seeds (love it)
• Madrone Wood
• Daisies
• Blossoms
• Cherry Wood
• Daylilies
• Pecan bark
• Cholla Wood (love it)
• Grape Vine
• Pinecones
• Oak leaves and bark
• Irish Moss
• Violet flowers

Note: If you are going to use wood in your crabitat, I would advise to quarantine (cure) it first. You can boil it (to clean from parasites, hitchhikers, and fungal spores) o put it in the oven (if it is small enough).

Other Foods and Things Your Hermit Crab Will Enjoy

• Bee pollen
• Calcium carbonate powder
• Cheese (all natural, only as a treat)
• Crustaceans (any, yes hermit crabs are cannibals)
• Feces (only from healthy, pesticide and parasite free, unmedicated animals)
• Honey
• Pasta
• Peanut butter
• Worm castings

Note: Do not give it too much and too often.

Preparing Food for Your Hermit Crabs

Hermit crabs locate food in two ways, by seeing other hermit crabs eating and by smelling it. Like most animals hermit crabs are most interested in foods with a very pungent aroma. The more it smells, the better it tastes. Even if you find the smell, or ingredients unpleasant, chances are your Hermit crab will think he's been served up a 5 course meal, at 6 star resort. Note: According to different studies, Hermit crabs can smell the food up to 5 meters (16 ft).

No matter where you source ingredients for your Hermit crab's meals, be sure they are pesticide free. In the case of plants and trees, your own back yard is a safer option than a nursery, or garden center. However, I would still recommend curing them first.

Although, many of the plants can even be grown inside the crabitat, it will not be a good idea (except Chia seeds). You can read more about it in my article “Hermit Crab Tank Setup”.

Hermit Crabs and Junk Food

Like us, Hermit crabs have been observed to have a natural junk food preference. They will happily eat chips, candy and other unhealthy foods. Despite your crab's junk food desires, you should avoid giving these to your crabs, even as treats.

All Ingredients You Use should be Food Grade Quality

This is especially important when using snails, mushrooms and vitamin supplements etc. Many of the things that are toxic to us, are also toxic to our pets. Never feed your hermit crabs wild snails, unresearched plants, unknown berries, or unidentified mushrooms.

How Often should We Change the Menu?

In the experiment, when biologists gave Hermit crabs the non-renewed and non-varied feed, the consumption decreased from day to day. The reduction reached 75% for the favorite feed (apple and jicama) on the second day. After 2 days, the feed was practically not consumed. However, if your Hermit crabs have a wide choice of food (4 – 6 different types), in this case, I would not worry much. Just do it from time to time.

How Often Should We Change the Food?

Do not leave food in the crabitat for too long. It can soil, rot, get moldy, etc. Change the food every day.

Conclusion

Although, Hermit crabs are omnivorous type of animal and have a broad spectrum of food, their feeding habit is quite unique. They are known to avoid the food that has previously been consumed and instead prefer new food. The crabs do this to reduce the amount of toxins entering their bodies and to regulate the balance of nutrients. Hermit crabs can be very picky eaters and have an ability to seek out the nutrients they are looking for.