Diet Guide

by The Crab Street Journal

 

When most people think about hermit crabs, they envision small, hardy creatures shuffling around in decorative shells. Unfortunately, this image overshadows a serious issue in hermit crab care: the lack of proper nutrition. For decades, hermit crabs have been marketed as low-maintenance pets, often with little to no guidance on their complex dietary needs. This widespread misinformation has led to a hidden crisis that severely impacts the well-being of countless hermit crabs.

The Misconception of Commercial Diets

Walk into any pet store, and you will likely find commercial hermit crab food advertised as “complete” and “nutritious.” However, these products often fall far short of meeting the dietary requirements of hermit crabs. Many are packed with harmful preservatives, artificial dyes, and low-quality ingredients that don’t provide the variety of nutrients hermit crabs need. Worse still, some contain ethoxyquin or copper sulfate, which are toxic to crabs in the long run.

In the wild, hermit crabs forage for a wide range of food, including fruits, vegetables, proteins, calcium sources, and even leaves and bark. This natural diet is rich in vitamins, minerals, and essential nutrients. Expecting them to thrive on highly processed pellets is unrealistic and, frankly, dangerous.

The Importance of a Balanced Diet

Hermit crabs require a diverse diet that mimics what they would find in their natural environment. Without it, they suffer from nutritional deficiencies that can lead to weakened exoskeletons, poor molting, and even death. Key elements of a balanced diet include:

Proteins

Vital for growth and molting, crabs need high-quality protein sources such as seafood, eggs, and lean meats.

Calcium

Essential for strong exoskeletons, calcium can be found in cuttlebone, eggshells, and natural coral.

Fruits & Vegetables

These provide essential vitamins and minerals. Fresh, pesticide-free options are always best.

Leaf Litter and Moss

Often overlooked, but crabs enjoy munching on leaf litter and moss, which provide fiber and beneficial microorganisms.

What Happens Without Proper Nutrition?

When deprived of a varied and nutritious diet, hermit crabs can suffer from a range of health issues, many of which are preventable. Some common consequences include:

Failed Molts

Molting is a delicate process, and without the right nutrients, hermit crabs may have incomplete or fatal molts.

Weak Exoskeletons

Calcium deficiencies can cause soft, fragile exoskeletons, making crabs more susceptible to injury.

Lethargy and Behavioral Issues

Hermit crabs that lack energy-rich foods may become sluggish and show little interest in foraging or climbing, which are natural behaviors.

 How to Improve Hermit Crab Nutrition

Caring for hermit crabs means providing them with a wide range of safe, natural foods that meet their nutritional needs. Here are some tips to ensure your hermit crabs get the nutrients they need to thrive:

Offer Variety

Rotate different food items like seafood, fresh vegetables, fruits, and calcium sources regularly.

Choose Natural Options

Avoid commercial foods with preservatives or artificial ingredients. Instead, opt for fresh or dried foods free from chemicals.
- Incorporate Foraging: Encourage natural foraging behaviors by providing safe enrichment items like leaf litter, moss, and bark.

Supplements

Occasionally offer calcium-rich supplements like cuttlebone, egg shells or natural coral to ensure your crabs are getting enough calcium.

The Role of Awareness in Hermit Crab Care

One of the greatest barriers to better hermit crab nutrition is awareness. Many new owners simply aren’t aware of the unique needs of these animals, and the available care guides don’t emphasize the importance of diet. By spreading accurate information, we can improve the health and longevity of hermit crabs in captivity and ensure that they live fulfilling, natural lives.

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Proteins and lipids 

All meats, meat fats, domestic, fish, seafood (silversides, goldfish, clams, oysters, crab, shrimp, tuna, salmon (skin and fat) bone marrow), nut meats, avocado (meat only), bamboo stalks (not lucky bamboo), egg yolks, pumpkin seeds. 

Oils (preferably cold pressed): coconut, olive, palm, sunflower, pumpkin seed 

Alfalfa hay, broccoli, egg whites, flax seed, bloodworm, plankton, shrimp, kale, lentils, millet, rice, snap peas, soy beans, spinach, wheat germ, quinoa, spirulina. 

Benefit: growth, molting, fueling metabolic function, discourages cannibalism 

 

Carotenoids, Zeaxanthin, Cellulose 

Tannin rich leaves, bark, cambium (inner skins) of oak, maple, mangrove root, some perennial leaves (Burning Bush). Fresh fruits and vegetables that are orange/yellow/red/dark green: Squash, sweet potato, carrots, corn, mango, blueberries, many flower petals (dry), spinach, fall foliage, bean sprouts, seaweed (especially spirulina), moss, acorn meat, avocado meat (only), bell peppers (orange, yellow, red), brussel sprouts, cilantro, collards, corn, corn meal, dandelion greens, egg yolk, grape leaves, romaine, papaya, parsley, peas, raspberry 

(leaves too), snap beans, pumpkin, pineapple, persimmon, peaches, passion fruit, microalgae, mango, apricot, cantaloupe, chard, guava, shellfish, salmon, tomato. Astaxanthin is found in microalgae, yeast, salmon, trout, krill, shrimp, crayfish, crustaceans, and the feathers of some birds. Benefit: immune system, nervous system, color enhancement 

 

Carbohydrates 

• Coconut, walnut, whole fish (like a dead goldfish), fish skin, animal fat, olive oil, some grass seeds, seeds, peanut 
• butter. Fresh flower petals: roses, sunflower, crab apple blossom 

 

Calcium 

Freeze dried brine shrimp, meal worms, blood worms, krill (fresh, frozen, freeze dried), sand dollars, starfish, sea urchin, powdered oyster shells, cuttle bone, figs, microalgae, nuts, okra, quinoa, broccoli heads, amaranth, beans, molasses, egg shells, milk, bone meal, seaweeds. 

Benefit: healthy exo and other functions Chitin 

Shrimp, crab, lobster, crawfish (shellfish should be boiled first), insect exoskeletons (such as cicadas), mushrooms. Greensand, worm castings.

Hermit crabs missing one or both claws should be fed soft (liquid) foods that can be picked up by the maxillipeds. Honey or molasses mixed with other foods is a good food for highly stressed crabs or clawless crabs but only in a tiny drop. Generally speaking most foods are equally valuable and getting the hermit crab to eat is more important than what it eats to begin with. Offering favorite foods to stimulate the appetite and fuel the metabolic function is your starting point, from there begin to incorporate foods from all of the above groups so that the crab has access to what its body needs to recover. Hermit crabs that are inactive and/or appear ‘dry could be lacking something. 

 

Note: 

Some dry foods (egg shells, grains, seeds, flowers, seaweed) can be sprinkled into the crabitat to encourage foraging behavior. 

Greensand and worm castings should be available at all times. 

 

Here’s a detailed safe food list for hermit crabs, broken down by category, with a focus on value and variety. These foods help support their health and well-being. 

Animal Proteins 

Hermit crabs need protein to grow and maintain their exoskeletons. 

- Dried/Cooked shrimp – High in protein and calcium. 

- Mealworms (dried or dead,) – Rich in protein and fats. 

- Boiled eggs (crushed shell included)– Excellent calcium source. 

- Cuttlefish bone– Great for calcium.

 

Vegetables 

 Fresh vegetables provide vitamins, minerals, and antioxidants. 

- Carrots – High in beta-carotene, which enhances shell color. 

- Sweet potato - Packed with fiber, beta-carotene, and energy. 

- Kale - Rich in vitamins A, C, K, and calcium. (Needs to be cooked) 

- Zucchini - Hydrating and full of essential vitamins. 

- Spinach– Contains lutein and iron. (Needs to be cooked) 

 

Seeds & Grains

These are great for energy and nutritional balance. 

- Chia seeds – High in omega-3 fatty acids and fiber. 

- Quinoa – A complete protein source, rich in amino acids.

- Flaxseed – Loaded with omega-3 and antioxidants. 

- Millet – Nutrient-dense, with vitamins B and iron. 

 

Nuts 

 A good source of fats, protein, and antioxidants. 

- Walnuts - High in omega-3 fatty acids and antioxidants. 

- Almonds – Rich in protein, fiber, and healthy fats. 

- Pecans - Provide antioxidants and a good fat source.

- Hazelnuts - Packed with vitamins and minerals.

 

Fruits 

Hermit crabs love fruits, which provide hydration, vitamins, and natural sugars. 

- Blueberries - High in antioxidants and anthocyanins.

- Apples (remove seeds) – A source of fiber and hydration. 

- Papaya - Contains digestive enzymes and vitamins. 

Mango - Rich in vitamins A, C, and antioxidants. 

 

**Foraged Greens & Plants** 

Hermit crabs benefit from foraging on natural plants. 

Dandelion greens 

A good source of calcium and vitamins. Plantain leaves 

High in fiber and healing properties. Hibiscus flowers 

Vitamin C and antioxidants. 

Anthocyanin-Rich Foods 

These provide powerful antioxidants that boost health and enhance color. 

Purple cabbage 

Anthocyanins and vitamin C. 

Blackberries 

Rich in antioxidants and nutrients. Chokeberries 

Another excellent source of anthocyanins. Red grapes 

Provide hydration and antioxidants. Supplements & Boosters 

Provide these at all times to boost their nutritional intake. 

Worm castings 

A natural source of nutrients and minerals.

Green sand 

Full of minerals. 

Bee pollen 

Vitamins, protein, and enzymes. 

Cuttlefish bone & Egg shells 

A constant source of calcium for 

exoskeleton health. 

Beta-Carotene-Rich Foods 

These enhance the vibrant colors of your crabs' exoskeletons. 

Pumpkin 

Rich in beta-carotene and fiber. 

Red bell peppers 

High in vitamin C and beta-carotene. Butternut squash 

Contains beta-carotene, fiber, and vitamins. Carrots 

Loaded with beta-carotene for healthy coloring. 

 

Fat Sources 

Essential fats help hermit crabs maintain energy and healthy growth. 

- Coconut oil 

A good fat source for energy and shell care. Sunflower seeds 

High in fats and nutrients. 

Hemp seeds 

Contain omega-3 and omega-6 fatty acids. Salmon oil 

Rich in omega-3 fatty acids and antioxidants. Lutein & Zeaxanthin-Rich Foods 

These protect eyesight and enhance overall health. 

Marigold petals 

High in lutein and antioxidants. 

- Peas – Rich in lutein and protein. Collard greens 

Packed with lutein, calcium, and fiber. (Need to be cooked) 

Corn kernels 

Contains zeaxanthin and offers fiber. – 

 

General Feeding Tips 

- Always wash fruits, vegetables, and foraged items thoroughly to remove pesticides and chemicals. 

- Avoid foods that contain salt, 

preservatives, or artificial ingredients. 

- Offer a wide variety to ensure a balanced diet and prevent boredom. 

- Replace uneaten food regularly to prevent spoilage and mold.

This detailed list covers a broad spectrum of safe, nutritious foods to help hermit crabs thrive!

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By being mindful of the food we offer our hermit crabs, we can drastically improve their health, happiness, and longevity. With proper care, including a nutrient-rich diet, hermit crabs can thrive and become fascinating, long-term companions.

 

Not sure where to get nutritional and safe hermit crab food? Check out some options here!