Nutrition is a vitally important part of keeping captive Hermit Crabs happy, healthy and thriving. It's all well and good to understand what crabs can and can't eat, but knowing why they need it and what portions they need is even more important.
Being Omnivores, Hermit Crabs will eat meats, vegetables, fruits, nuts, seeds, seafoods, wood, leaves, flowers etc.
Hermit Crabs need a varied diet daily to cover all of their nutritional needs, if they are lacking in a certain area, they may go to extreme lengths to try and fill that void. One such instance is a lack of protein in the diet, this can cause a Hermit Crab to eat their fellow tank mates in order to fill that protein need.
Below we will talk about what Hermit Crabs need in their diet, how much and why it is beneficial.
Proteins & Lipids
Sources - chicken, beef, pork, lamb, turkey, duck, kangaroo, eggs, insects, beans, green vegetables, lentils, quinoa, fish, chickpeas, turkey, almonds, pumpkin seeds, shrimp, spirulina, oats, chia seeds, cashews, seaweed.
Daily Portion - Protein should make up 50% of a crab's daily diet.
Benefits - A lack of protein will lead to slow growth and cannibalism. Protein aids in the growth and maintenance of healthy tissues in your Hermit Crab as well as fueling metabolic functions.
Omega 3 Fatty Acids
Sources - egg yolk, salmon, coconut, insects, avocado, chia seeds, walnuts, flaxseed, hemp, spinach, anchovies, brussel sprouts, herring, sunflower seeds, oysters.
Daily Portion - Omega 3 Fatty Acids should be a regular part of your crab's daily diet.
Benefits - Adding Omega 3 Fatty Acids to your crab's daily diet aids in a healthy and successful moult, building a healthy exoskeleton, and aids in the nervous system. It also aids in the breakdown and processing of Carotenoids.
Calcium
Sources - star fish, cuttlefish bone, sea urchins, sea biscuits, sand dollars, coral, eggshells, oyster shell, insects, crab exoskeleton, broccoli, spinach, kale, chia seeds, almonds, flaxseed, sesame seeds, hazelnuts, pistachios, walnuts.
Daily Portion - Calcium should be available at all times within your tank.
Benefits - Calcium is a vitally important nutrient that promotes a healthy exoskeleton, and aids in the hardening of the new exoskeleton post moult.
Carotenoids (Zeaxanthin, Beta-Carotene, Lutein & Cellulose)
Sources - carrot, pumpkin, sweet potato, capsicum, broccoli, tomato, mango, banana, apricot, berries, cantaloupe, spinach, kale, avocado, egg yolk, watermelon, corn, butternut squash, capsicum, dandelion, peas, spirulina, calendula petals, celery, hemp, beans, pears, apples, lentils, brussel sprouts, wheat bran, safe wood, safe leaves, seeds, nuts, leaf litter.
Daily Portion - Carotenoids should be a regular part of your crab's daily diet.
Benefits - Adding Carotenoids to your crab's diet will aid in regulating their body systems, digestion, colour enhancement, immune system and nervous system.
Fibre
Sources - chia seeds, lentils, oats, almonds, raspberries, chickpeas, quinoa, avocado, apple, broccoli, sweet potato, popcorn, banana, barley, brown rice, pear, strawberries, artichoke, corn, psyllium husk, flaxseed, wheat bran, millet.
Daily Portion - Fibre should be a regular part of your crab's daily diet.
Benefits - Fibre aids in your crab's digestive health.
Carbohydrates
Sources - sweet potato, quinoa, banana, oats, brown rice, pumpkin, pear, apple, buckwheat, lentils, chickpeas, whole meal pasta, raisins, grain cereals, beetroot, blueberries, dates.
Daily Portion - Carbohydrates should be a regular part of your crab's daily diet.
Benefits - Carbohydrates give quick boosts of energy.
Foraged Foods (leaf litter)
Sources - oak leaves, maple leaves, sphagnum moss, rose petals, rose leaves, snake shed, alfalfa, hibiscus flowers, dandelions, calendula flowers, acorns, bamboo, birch wood, cholla wood, carnation flowers, chamomile, catappa leaves, mango leaves, cork bark, daisies, hazel, lilac, oak bark, pansies, pinecones.
Daily Portion - Different types of leaf litter/foraged foods should be available as part of your crab's regular daily diet, this aids in their natural foraging behavior's.
Benefits - Foraged foods are filled with various important nutrients that aid in your crab's overall health, as well as encouraging natural foraging behaviour.
Supplements
Sources - greensand, worm castings, insect frass, bee pollen, organic blackstrap molasses.
Daily Portion - Supplements such as greensand, worm castings and insect frass should be readily available at all times within the tank. Bee pollen and blackstrap molasses can be offered every few weeks as an extra supplement.
Benefits - Supplements are filled with beneficial vitamins and minerals that Hermit Crabs cannot gain from other food items.
Aquatic Plant Matter
Sources - kelp, bladderwrack, wakame, seaweed, coral, spirulina, Irish moss, dulse, sea palms, sea fans, algae.
Daily Portion - Aquatic plant matter should be a regular part of your crab's daily diet.
Benefits - Aquatic plant matter is filled with various vitamins and minerals crabs need to promote a healthy lifestyle and support their natural foraging instinct. These forms of foods are often found in a wild Hermit Crabs diet.
Vitamins (A, B1, B2, B3, B5, B6, B9, D, E, H)
Sources - carrots, spirulina, mango, pumpkin, dark leafy greens, wheat bran, peanuts, beans, pork, sunflower seeds, eggs, nuts, meats, cereals, poultry, fish, wholegrains, broccoli, cabbage, sweet potato, legumes, shellfish, mushrooms, tuna, salmon, capsicum, avocado, asparagus.
Daily Portion - Vitamins should be a regular part of your crab's daily diet.
Benefits - Vitamins help to fill the gaps in your crab's diet and ensure they are receiving all the necessary nutrients to stay fit and healthy.
By offering a complete and varied diet, you are encouraging a happy and healthy lifestyle for your Hermit Crabs. Foods should be offered both dried and fresh. Fresh foods will mold quicker and should be removed once they begin to turn bad, high quality dried foods should be replaced every 2-4 days or when the bowl is near empty. Rotating the foods on offer will keep your crabs interested at dinner time and will aid in keeping their diet varied. When offering foods, try to pick something from every category (proteins, vegetables, fruits, seafoods/aquatic plants, nuts and seeds, calcium, fats, carbohydrates) this will help to offer all crabs within your tank the current Nutrional requirements that they may need at that time.
You may find that your crabs gravitate towards dried foods rather than fresh, that is okay, as long as they are high quality handmade foods, they still offer just as many nutrients as fresh foods do.
Foods To Avoid
Any foods on the unsafe food list, which can be found here https://www.happyhermie.com.au/post/hermit-crabs-safe-and-unsafe-foods
Pet store processed foods such as crab pellets, Krabooz foods, crab powders, Hermit Crab labelled pet store foods.
Foods filled with pesticides, preservatives, salts, sugars, treated flowers and leaves.
Rotten foods
Fatty, sugary, salty snacks
Candies, chocolate, chips etc.
Foods cooked with onion and garlic.
Do things like carrot/broccoli/mushroom need to be cooked, or it doesn't matter either way?