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  • Writer's pictureKat

Why You Should STOP Using Cuttlebone!

Updated: Jul 18, 2023

What is Cuttlebone?

Cuttlebone is a frequently used source of calcium for our beloved pets. They're recommended our pet fish, birds, and reptiles.

But what actually is it? For Cuttlebone not even really a bone - it is the internal shell of an adorable little guy called a cuttlefish (who actually isn't actually a fish!) Undeniably, there is a lot of confusion surrounding the cuttlefish, so lets find out a little more about them!

A cuttlefish is a marine mollusc, and is in the same family as squids and octopus. There are about a hundred different species of cuttlefish, ranging from as small an one inch (about the size of half of your thumn), all the way up to 35 inches (about the size of a baseball bat). Regardless of size, they all have 8 arms and two tentacles which they use to capture prey.

Cuttlefish also have a large brain relative to their body size, and are often regarded to be some of the most intelligent invertebrate animals on the planet! They can change their colors like a chameleon for evading predators, and breeding. And you might not believe this but... they can actually count! Yes, count! like human number 1,2,3,4 COUNT! A 2016 study placed 54 different cuttlefish in chamber tanks, where they would have to pick from two food options such as 4 shrimp, or 5 shrimp. the cuttlefish consistently picked the greater amount of shrimp just by looking at how many there are in each chamber!

Unfortunately though, one cuttlebone = a dead cuttlefish. And the worst part? Our pets dont even really like cuttlebone!

How many times have you thrown a cuttlebone into your tank, just to have it be ignored by all your shrimp and snails?

Even bird and reptile keepers agree that the large majority of their pets seem to ignore the cuttle bone. Many pet owners resort to "forcing" the cuttlebone into their diet by shredding the bone, and sprinkling it on top of all of their food, or swishing it into the water column.

So lets really break down the downfalls of cuttlebone:

  • The result of animal exploitation.

While KatsAquatics does not necessarily preach veganism, we can all disagree with exploiting an animal for only a piece of their body, and discarding out the rest. That is essentially what happens with Cuttlefish when they are harvested only for their cuttlebone. Cuttlebone isn't yet a sustainable source of calcium, and there are no works in progress as of 2020 to make it one.

  • Unappetizing to most animals

While advertised for to be for snails, reptiles, and birds, the large majority of pet

keepers can agree that their animals have very minimal, if any interest in the bone.

Many pet keepers note the cuttle bone sitting in their animal enclosures untouched. This can often result in desperate calcium inclusion attempts such as grinding the cuttlebone, adding it to fish tanks, and reptile food. Animals feel when they have a deficiency, and will do everything they can to fulfill it. When provided will proper nutrients, lizards and hamsters will willingly lick up the nutrient powders (such as ones by Repashy), and inverts will swarm calcium tablets. If our pets are ignoring the cuttlebone, it is for a reason unbenounced to us. So why force cuttle bone into their diets, if there are other options that your animals will readily accept?

  • Eyesore in the Fishtank

So many snail and shrimp keepers invest hundreds of dollars, and dozens of hours of work into making their fishtanks perfect. After so much hard work we shouldn't need to stick a large white slab into the middle of the tank to ruin potentially ruin aesthetics, and water quality.

The swings in water parameters caused by cuttlebone can be deadly for more sensitive fish tank inhabitants such as caridina shrimp.

  • Lacks Nutrients

Cuttlebone is about packed with calcium, that's true. In fact, it is composed of about 85% crystallized calcium carbonate - however that's about all that it is. It severely lacks major nutrients required by a large array of animals such as phosphorous, vitamins, and even fibers. In fact, calcium has a difficult time being absorbed by animals if it is not couple with vitamin D. That could be a major reason why animals simply aren't drawn to it - why consume calcium, if their bodies won't have the full capacity to absorb it? KatsAquatics tablets contain the essential nutrients and minerals needed for optimal funciton, and they're all derived from whole foods. Our varieties are packed with nutrients from vegetables such as beets, spinach, pumpkin, and of course egg protein (which is packed with essential vitamin D!) This ensures your pets get calcium, and everything else they need to thrive all in one tablet.

  • Purchasing cuttlebone = supporting foreign business

Since cuttlefish are live marine animals, they're not found in every part of the world. In fact, they're almost exclusive to the Mediterranean, and North and Baltic Seas. This means that foreign fishermen usually harvest these guys, and they don't have to follow the USDA's rules and regulation on animal welfare. It is always better to support domestic/local businesses to make sure you're supporting valid and humane practices.

So, how do I get calcium to my pets without using cuttlebone?

After breaking down the negatives of cuttlebone, switching calcium supplements seems to be a no brainer. There are a small handful of small business owners that sell calcium that we definitely recommend supporting.

KatsAquatics is a small (for now!), American business that makes all of their products right here in the USA. KatsAquatics calcium never has any cuttlebone in it, and is made from a 100% sustainable calcium carbonate source. We make specialized calcium tablets for aquatic inverts such as snails, and shrimp, and ensure that your aquatic pals get all of the nutrition they desire. With so many different flavors and varieties, the only difficulty with us is which calcium to choose because they're all so amazing in their own unique way!

We also make a pure calcium powder that can be used together with your bird or reptile food! The calcium powder is guaranteed to be 100% natural calcium carbonate. So you don't have to worry about any added D3 vitamins (which can be dangerous to your reptiles).

While for now we do specialize in aquatic invertebrates, sign up to our email list to keep your eyes peeled for reptile products coming soon! We are working on perfecting the calcium formulas for your isopods, crickets, lizards and turtles!!!

Thank you for reading!

Make sure to check out

Stay tuned for more calcium!!!

As always, Live Long, and Swim Strong

Warmest regards, Katrine, the "Kat" in KatsAquatics!


3,583 views2 comments


roger logue
roger logue
Dec 18, 2021

Kat I absolutely love this post, and have referred multiple people to this as a resource. I'm fairly certain we have talked before about my personal crusade of stopping the use of cuttlebone. Every time I see ANYONE suggest cuttlebone I send them to you!! I truly hope for the cuttlefish (and you), people switch to your products which is now my ONLY go to for calcium supplements! Keep up the great work!

Dec 19, 2021
Replying to

Thank you so much Roger! It's a pleasure to help spread more information through out the hobby! I'm eternally thankful for fellow fish keepers like yourself who strive to help make fish keeping, and the world a better place!

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