Kilimanjaro's Guide to Hermit Crab Nutrition

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Kilimanjaro's Guide to Hermit Crab Nutrition

Post by Kilimanjaro » Wed Jul 30, 2008 4:08 pm

THE UPDATED ARTICLE CAN BE FOUND HERE: [Care: Hermit Crab Nutrition by Kilimajaro].

Questions about anything on this page - or questions about any food item - should be directed to the [Food & Water] section as a new topic.


Kilimanjaro's Guide to Hermit Crab Nutrition

First off, I would like to thank member blaze88 for helping me out on this guide. Blaze contributed a ton of information to incorporate into this guide for everyone to use and understand. Thank you so much for being a huge help!

Introduction to the Guide
I decided to formulate a guide to hermit crab nutrition due to the incomplete knowledge of hermit crab diet out there. Many new members are confused about what to feed their crabs and senior crabbers are also looking to provide a good diet for their land hermit crabs.

There is no complete guide to hermit crab nutrition (as this is not a complete guide) and there is no magic kibble that can possibly contain all of the foods that crabs need. This is because variety is the key to offering different nutrients that the hermit crab has a need for. New foods should always be incorporated into a land hermit crab's diet.

The guide that is made up here is broken down into different nutrients and different food groups that crabs need. In the nutrients section I tried to identify the nutrient, explain what it does in the crab's body, and then give examples of foods that are high in this particular nutrient. In the food groups section, I tried to identify the food group, explain why it is important, and then give examples of foods that are in this group.

Additionally, the guide provides a list of favorite foods, a section regarding molting and feeding, and a food warning section.

Without further adieu, I present Kilimanjaro's Guide to Hermit Crab Nutrition!


Key Nutrients
There are many key nutrients needed in a crustacean's diet. Protein is a particularly important nutrient that many crabbers do not offer enough of. It is imperative to get a source of protein in your hermit crab's diet every night (or feeding period).

The key nutrients are listed in alphabetical order.

Astaxanthin
Definition - a strong pigment molecule that is usually found in rich red foods.
Function - enhances color in land hermit crab's exoskeleton and aids in keeping organ systems and bodily functions healthy.
Foods - krill, plankton, red seaweeds, shrimp

Beta Carotene
Definition - an orange and red pigment molecule that is found in brightly-colored foods.
Function - enhances red and orange color in hermit crab's exoskeleton and is processed into Vitamin A in a hermit crab's body
Foods - apricots, bell pepper (red, orange, and yellow), blueberry, broccoli, cantaloupe, carrot, chard, cilantro (raw), collard greens, dandelion greens (raw), lettuce (dark), mango, microalgaes, papaya, parsley (raw), passionfruit, peaches, peas, persimmon, pineapple, pumpkin, snap beans (raw), spinach, spirulina, squash, seaweeds, sweet potato

Calcium
Definition - a soft-grey alkaline earth metal (Ca)
Function - aids in exoskeletal health and works as a signal in many cellular functions, including brain function
Foods - amaranth, blackstrap molasses, broccoli, cuttlebone, eggshell, exoskeleton, figs, microalgaes, nuts, okra, orange, oyster shell, quinoa, seaweeds, seeds

Carbohydrates
Definition - a biomolecule that is processed into sugar in the bodies of all living things
Function - store and transport short-term energy and make up part of the chitin in the exoskeleton
Foods - fruit (assorted), grains, honey, microalgaes, noodles, quinoa, rice, seaweed, vegetables (assorted and especially dried), wheat germ

Cellulose
Definition - a compound making up many tissues and cell walls in plants
Function - provides fiber in diet and also contains many color-enhancing molecules
Foods - fruits, tree bark, tree leaves, vegetables

Fats (Lipids)
Definition - molecules that store energy and are found in solid (fat) or liquid (oil) forms
Function - used to make cell membranes and dissolve certain vitamins
Foods - almonds, canola oil*, coconut, coconut oil*, egg yolks, meat fat, olive oil*, palm oil*, pumpkin seed oil*, pumpkin seeds, salmon, sunflower seed oil*, sunflower seeds, walnuts
*when picking an oil, cold-pressed oils are the best choice

Other Carotenoids
Definition - molecules that enhance color and reflect different wavelengths of light
Function - enhance color in the hermit crab exoskeleton and aid in bodily functions and keeping organ systems healthy
Foods - apricot, blueberry, carrot, collard greens, egg yolk, guava, kale, mango, pink grapefruit, salmon, shellfish, spinach, squash, sweet potato, tomato

Phytonutrients
Definition - small compounds and molecules that are important in a diet, but too small and too insignificant to research and understand
Function - keeps bodily functions and organ systems healthy
Foods - any nutritional food

Protein
Definition - a compound made up of many smaller amino acids
Function - keeps exoskeleton, muscular, and other bodily systems healthy, and allows the body to process carbohydrates and lipids
Foods - alfalfa hay, broccoli, crab, egg whites, flax seed, freeze-dried bloodworm, freeze-dried plankton, freeze-dried shrimp, game meat, kale, lean beef, lean chicken, lean turkey, lentil, millet, rice, salmon, shrimp, snap peas, soy beans, spinach, tuna, wheat germ

Tannin
Definition - a pigment molecule that is found in fibrous foods
Function - enhances color in land hermit crabs and keeps bodily systems healthy
Foods - roots, tree bark, tree leaves

Vitamins
Definition - a compound that cannot be synthesized by an organism and thus is required by consuming
Function - keeping bodily systems, appearance, and organ systems healthy
Foods - various fruits, vegetables, and other food groups

Zeaxanthin
Definition - a carotenoid found in various foods
Function - enhances color of the exoskeleton and also aids in bodily functions
Foods - avocado, bell pepper (orange and red), broccoli, brussel sprouts, carrot, cilantro, collards, corn (yellow), corn meal, dandelion greens, egg yolk, grape leaves, lettuce (romaine), papaya, parsley, peas, raspberry, spirulina


Key Food Groups
After much talk and figuring, blaze88 and I have managed to come up with seven different food groups and foods that are in each group. The food groups have been arranged into a hermit crab food pyramid.

Please keep in mind that the pyramid below is a guide to feed. By no means do you have to follow the schedule exactly. These guidelines are scientifically backed by the book Crustacean Nutrition (reference below).

If your land hermit crabs do not eat all of the food based on the schedule, do not fret. Crabs can be picky eaters and have an ability to seek out the nutrients they are looking for. By feeding all of the food groups on the pyramid when required, you are verifying that you are giving your land hermit crab access to all the nutrients they need.

The hermit crab food pyramid is very user-friendly and easy to read. The foods on the bottom are most important the foods on the top are less important. However, all of the food groups are imperative to hermit crab health. The key on the right-hand side describes how many times to feed this food group a week. When the pyramid level is broken in half, you can choose either food group. The larger the section, the more important it is.

Image

I have decided to explain the food groups in order of importance.

Animal Protein & Plant Protein
This group is most important to a land hermit crab's diet. Foods high in protein should be fed every day so the land hermit crab can access the correct amino acids it requires. Animal proteins are more important than plant proteins, but plant proteins can be fed along with animal proteins.
Foods of the animal protein group include: crab, egg whites, freeze-dried bloodworm, freeze-dried plankton, earthworm, freeze-dried shrimp, game meat, lean beef, lean chicken, lean turkey, salmon, shrimp, tuna
Food of the plant protein group include: alfalfa hay, broccoli, corn, flax seed, kale, lentil, millet, rice, snap peas, soy beans, spinach, wheat germ

Sea Vegetables & Harvestables and Fruits & Vegetables
This group is important to a land hermit crab's diet because it is diverse in many different nutrients. Sea vegetables are high in many necessary minerals and harvestable foods are high in many other nutrients. Fruits and vegetables come along with many different types of vitamins and healthy nutrients. It is important to offer a variety of foods from this level of the food pyramid.
Foods of the sea vegetables group include: algae, kelp, nori, spirulina, wakame, various algae, various seaweeds
Foods of the harvestables group include: (see Harvestables list)
Foods of the fruits and vegetables group include: apple, avocado, banana, blackberry, blueberry, carrot, celery, cherry, coconut, fig, grape, guava, kiwi, lettuce (dark varieties), mango, orange, peach, pear, pineapple, plum, pomegranate, potato, pumpkin, raspberry, squash, tomato, various other fruits, various other vegetables

Calcium
This group is important in a hermit crab's diet because calcium is an important mineral that helps in exoskeletal health and other bodily functions. Calcium should be fed often and comes in a variety of different forms. Calcium can be fed in dairy forms, although some speculate that crabs do not absorb dairy calcium as well as hard forms. Any greens containing calcium should be quickly cooked in order to disable the oxalic acids, which can prevent calcium absorption. Care should be taken to pick foods with calcium that are also low in oxalic acids and phosphorus.
Foods of the calcium group include: amaranth, beans, blackstrap molasses, broccoli, cuttlebone, dark greens (cooked), eggshell, exoskeleton, figs, microalgaes, nuts, okra, orange, oyster shell, quinoa, reptile calcium supplement, seaweeds, seeds

Fats (Lipids)
This group is important in a hermit crab's diet because it can help in molting and also stores energy. Fats are found in plant and animal forms. Fats are not needed in as high amount as protein, which is why when crabs are feeding on an animal protein source it should be lean. There are some beneficial fats and oils in a hermit crab's diet. The two fatty acids that hermit crabs require are n-3 and n-6, which are found in oils and some other sources of fat.
Foods of the fats group include: almonds, canola oil, coconut, coconut oil, egg yolks, meat fat, olive oil, palm oil, pumpkin seed oil, pumpkin seeds, salmon, sunflower seed oil, sunflower seeds, walnuts

Other
This group is not as important as the other groups, and, in fact, is optional. These foods can be chosen to fed or they can be disregarded. The foods in this group can have beneficial factors and nutrients. This group is very diverse and contains some of the favorite foods of land hermit crabs. Some of these are great healthy treats and others, like vinegar, help with illnesses like post-purchase syndrome (PPS).
Foods of the other group include: blackstrap molasses, cuttlebone, earthworm castings, eggshell, honey, mineral supplements, oyster shell, saltwater, vinegar (with mother)


Hermit Crab Nutrition and the Molting Cycle
Pre-molt and post-molt crabs require different foods as far as regular hermit crab nutrition goes. Before molts, many land hermit crabs are known to eat a lot to gather enough energy and nutrients to sustain themselves throughout molts. Additionally, most land hermit crabs will eat a lot to regain nutrients so they can get back to their normal selves.

What to Feed Pre-Molt Land Hermit Crabs
It is important to feed pre-molt hermit crabs foods rich in different nutrients. Protein and calcium are two of the most important nutrients you can feed your land hermit crabs when they are pre-molt.

Some people have noted that oils help land hermit crabs shed their exoskeleton. Feeding different oils (coconut, red palm, or olive) can be beneficial to a pre-molt hermit crab.

What to Feed Post-Molt Land Hermit Crabs
Post-molt land hermit crabs should be fed a various diet with foods rich in different vitamins and other beneficial nutrients. You should try to feed the healthiest foods to your post-molt crabs for a week or two in order to have them regain their nutrient levels and they start to metabolize food easier.

But What Happens When They're Underground?
Land hermit crabs eat a lot prior to a molt so they are able to sustain themselves. The molt sac does not contain many nutrients, but water. The water pressure helps them break their exoskeleton during the molt.

Because they do not eat when they are molting (besides their exoskeleton to regain nutrients for the new one), good foods should be fed before molts and afterwards.

Reference:
Crustacean Nutrition
By Louis R. D'Abramo, Douglas E. Conklin, Dean M. Akiyama, International Working Group on Crustacean Nutrition, World Aquaculture Society
Published by World Aquaculture Society, 1997
ISBN 1888807008, 9781888807004
587 pages

Hermit Crab Food Favorites
Hermit crabs enjoy certain foods that are high in nutrients and can also satisfy them with a certain taste. Some of the hermit crab favorite foods I have collected came from the forum. I have decided to post the most popular foods.

Bloodworms (freeze-dried)
Blueberries
Chicken bone marrow
Coconut
Cuttlebone
Earthworm castings
Krill (frozen & thawed or freeze-dried)
Mango
Millet
Oak leaves
Papaya
Peanut butter (organic)
Persimmon
Pineapple
Popcorn (no butter or salt)
Rolled oats
Shrimp (whole)
Wheat germ


Hermit Crab Food Warnings
Although there are many foods that are safe for hermit crabs, there are some unsafe foods and some food warnings.

Food Warning #1: Unsafe Foods
To view both safe and unsafe foods, please visit Hermit Crab Cuisine where you can view both safe and unsafe foods. Safe and unsafe food lists are also available here as stickied threads in the Food & Water forum. Keep in mind that the safe food list is not a complete list, and more foods are always being added.

Food Warning #2: Oxalic Acid in Greens
Many greens have oxalic acid inside of them. Oxalic acid binds to calcium and makes it unprocessable by reptiles, humans and other mammals. Foods high in oxalic acids should be avoided or fed sparingly.

Food Warning #3: Preservatives in Commercial Foods
There are many preservatives in commercial foods for land hermit crabs. A great topic to view here at the HCA is this one about additives and harmful substances.

The preservatives and harmful ingredients that everyone should be looking out for in commercial foods are artificial color, by-products, copper sulphate/sulfate, ethoxyquin, ferrous sulfate, foods containing "meal", magnesium oxide, menadione, propylene glycol, sodium chloride, zeolite, zinc oxide

There are many natural kibbles that can be purchased. The Hermit Crab Addiction Store is a great place to buy these natural kibbles, as well as The Hermit Crab Patch. Member spidtat is currently operating a natural food store for land hermit crabs, Keep on Crabbin', and member Kilimanjaro is currently selling natural and organic kibbles and foods at his store, Kilimanjaro's Kibbles.

Food Warning #4: Pesticides in Foods
Most of the fruits and vegetables we eat today have been sprayed with pesticides in order to produce more food to feed the growing population. Because pesticides and insecticides are designed to target the exoskeleton of insects, it is possible that pesticides can be harmful to hermit crabs because they also have an exoskeleton.

Many crabbers opt to buy natural and organic products in order to cut out pesticide consumption. Berries and thin skinned foods have the highest amount of pesticides in them and many crabbers make sure to buy these organic. Foods with thick peels or rinds absorb most of the pesticides in the skin and the skin should not be fed unless it is organic.


Conclusion
I would like to mention that this is not a complete reference to hermit crab nutrition, but simply a guide. Hermit crab nutrition is constantly changing and more is learned each day.

I am completely open to editing this guide. All comments, suggestions, questions, and criticisms are welcome to be posted. I value everyone's opinion and I would love to hear what you all honestly think.
Last edited by Kilimanjaro on Wed Aug 04, 2010 11:32 pm, edited 19 times in total.


Guest

Post by Guest » Wed Jul 30, 2008 6:43 pm

Fantastic job, Kili. It deserves a sticky and a crown. :smt029

I do have one question.

Seeing as I don't cook for myself, I certainly don't cook for my crabs. Most of the items that can be found at home, like peanut butter, fresh fruit and veggies, rolled oats, they won't touch. Popcorn, crushed nuts, my calcium mix, and shrimp tails are about it. I even got them jars of baby food.

So I have relied mainly on Blaze's kibble and foods from the Happy Hermit and The Crabbage Patch. I also have pet food containers of anole, bloodworms, Wardley premium food, krill, freeze dried worms and a bunch of other things.

So considering they're mainly getting 'packaged' food rather than fresh, do you think they're getting a healthy diet?






(Just goes to show that those in the know don't always know. :smt028 )

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Post by Kilimanjaro » Wed Jul 30, 2008 10:48 pm

Grammarcia,

If you are giving them a variety of dried foods that offer all of the nutrients that they need and you follow the food pyramid somewhat, then they are most likely getting a healthy diet.

I would make sure you are getting a good source of protein in their diet every night.

Additionally, you may want to feed a few different types of fresh fruit and veggies every week. This would help them out in case they are not getting any nutrients they require.

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Post by blaze88 » Fri Aug 01, 2008 1:03 am

I am bumping due to the lack of stickying!

Obviously I can't really give a fair answer to your question, but assuming I don't trust my food (which I do, but...) with dried foods the main lacking nutrients are A and C so foods with beta carotene and foods with vitamin C would be good, orange peals, pineapple, citrus and carrots.

But I tried to make up for all the loss in my kibbles, I am mainly saying this for dried foods in general.
coloradocritterco.com


Guest

Post by Guest » Fri Aug 01, 2008 9:02 am

Nice job! It's nice to have all that information in one. place.


Guest

Post by Guest » Fri Aug 01, 2008 9:37 am

Thanks for the answers, Blaze and Kali

We do always have fresh fruit, but they don't seem to like any of it. I guess the best thing to do is to keep putting it in, and let them make their own choices. I gave them sweet potatoes last night, which they seem to like.

And Blaze, believe me that I trust your kibble, I just feel when I read what others crabs chow down on, I usually don't know why my crabs don't.


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Post by Cynderella727 » Fri Aug 01, 2008 10:14 am

Fantastic job!
Mommy of 1 human, 1 cat, 2 dogs, and 6 Purple Pinchers.
~Crabby since July '07


Guest

Post by Guest » Fri Aug 01, 2008 11:44 am

this is definitely a thread to bookmark...a ton of useful info condensed into an easy-to-understand format. i learned quite a bit reading it. thanks a lot for compiling and posting all that, kilimanjaro! :clap:


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Post by Guest » Fri Aug 01, 2008 12:09 pm

Very very helpful, thanks!! :D

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Post by Kilimanjaro » Fri Aug 01, 2008 4:13 pm

Thank you for all of the kind compliments and words. Please be sure to thank blaze88, too.

Blaze88 = Gigantic Help.

:D

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Post by blaze88 » Fri Aug 01, 2008 4:51 pm

Yes, worship me too! :toothy1:

jk.
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Post by Tremors » Fri Aug 01, 2008 5:07 pm

Thanks both of you! That was very helpful. :D
4 PPs: Petra (11 years), Big Crab (7 years), Rambunctious Crab (7 years), John Smith (1 year)
3 Es: Pacman, Captain Janeway, Googely-Bear (2 years)


Guest

Post by Guest » Fri Aug 01, 2008 9:23 pm

hmm...well then this post officially adds a thanks from me to blaze88!


MudCrabDude

Re: Kilimanjaro's Guide to Hermit Crab Nutrition

Post by MudCrabDude » Sun Aug 03, 2008 3:26 pm

Kilimanjaro wrote: Animal Protein & Plant Protein
This group is most important to a land hermit crab’s diet. Foods high in protein should be fed every day ....
Foods of the animal protein group include: crab ...
:shock:
:faint:










:smt047


Guest

Post by Guest » Sun Aug 03, 2008 3:39 pm

I'm not so sure about your oxalic acid warning.

#1 Cooking those greens actually brings out the oxalic acid (see amaranth)

#2 Hermit crabs don't metabolize it the same way reptiles and mammals do.

Foods high in oxalic acid are an important part of a crabs' diet but should be fed sparingly and often when the plant is younger rather than more mature.

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