The Hidden Crisis: Hermit Crab Nutrition

Hermit crabs require a nutritionally complete diet. For optimal health feed from all food groups each day. Offer them a balanced diet daily and they will eat what their body needs.

When hermit crabs lack proper nutrition, especially calcium, it can lead to several health issues that affect their overall well-being:

  Weakened Exoskeleton

Calcium is crucial for hermit crabs to build and maintain a strong exoskeleton. Without enough calcium, their exoskeletons can become soft and brittle, making them more vulnerable to injury and unable to molt properly.

Molting Problems:

Hermit crabs need calcium to molt, a process where they shed their old exoskeleton and grow a new one. A lack of calcium can cause failed molts, which are often fatal, as the crab cannot grow a new exoskeleton effectively.

Lethargy and Weakness:

A poor diet lacking essential nutrients, including calcium, can lead to lethargy and a weakened immune system, leaving the crab more susceptible to disease and stress.

Inability to Repair Damage: Hermit crabs rely on calcium reserves to repair their exoskeleton after minor damage or injuries. Without enough calcium, they cannot heal or strengthen their exoskeleton.

To prevent these issues, hermit crabs need a balanced diet rich in calcium sources like cuttlebone, crushed eggshells, Oyster shells or specially formulated hermit crab food. Proper nutrition is essential for their survival and health.

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’ll 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 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.

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.

Here are a few examples of items for each of the hermit crab food categories:

  Animal Proteins

   - Dried shrimp

   - Mealworms

   - Boiled egg

Vegetables

   - Carrots (rich in beta-carotene)

   - Kale (Cooked)

   - Zucchini

   - Sweet potato

  Seeds & Grains

   - Chia seeds

   - Quinoa

   - Millet

   - Flaxseed

  Nuts

   - Walnuts

   - Almonds

   - Pecans

   - Hazelnuts

 Fruits

   - Blueberries (anthocyanins)

   - Mango (Fruit ONLY)

   - Papaya

   - Apple

 Foraged Greens & Plants

   - Dandelion greens

   - Clover

   - Plantain leaves

   - Hibiscus flowers

Anthocyanin-Rich Foods

   - Blackberries

   - Purple cabbage

   - Red grapes

   - Chokeberries

Supplements & Boosters

   - Cuttlefish bone

    - Calcium

   - Worm castings

   - Green sand

   - Bee pollen

Beta-Carotene-Rich Foods

   - Pumpkin

   - Butternut squash

   - Red bell peppers

   - Spinach

Fat Sources

    - Coconut oil

    - Sunflower seeds

    - Hemp seeds

    - Salmon oil

Lutein & Zeaxanthin-Rich Foods

    - Marigold petals

    - Spinach

    - Collard greens

    - Peas

Precautions:

● Dark greens and other foods high in Oxalic Acid should be cooked prior to serving. Oxalic Acid and

Phosphorus block calcium absorption.

● All shellfish should be boiled or steamed prior to serving to avoid the spread of diseases of the exoskeleton

● Pesticide free is a must.

Proteins and lipids

All meats, meat fats, domestic, wild game, fowl, fish, seafood (silversides, 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, 

beans, spinach, wheat germ, quinoa, spirulina.

Benefit:

growth, molting, fueling metabolic function, discourages cannibalism

Carotenoids, Zeaxanthin, Cellulose

Tannin rich leaves, bark, cambium (inner branch 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

Grape, apple, grains, wheat germ, rice, oatmeal, dried fruit (mostly raisins due to copper sulfate use in others),

banana, pineapple, citrus pulp (inner membrane of skin considered cellulose), dried vegetables, seaweed.

Benefit: quick energy (fuel)

Omega Fats

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

Benefit: nervous system, exo, processing minerals (including carotenoids)

Calcium

Freeze dried brine shrimp, mealworms, blood worms, krill (fresh, frozen, freeze dried), sand dollars, starfish, sea

urchin, powdered oyster shells, cuttlebone, 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.

Benefit:

healthy exo

Other beneficial foods

Greensand, worm castings,

What to feed sick hermit crabs?

Hermit crabs missing one or both claws should be fed soft (squishy or 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 in

Omega fats. Lack of Omega fats could play a role in molt deaths.

Note

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

foraging behavior. Replenish when depleted.

Greensand and worm castings should be available at all times.

Astaxanthin sources must be paired with fats to be properly absorbed.

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