NomSafeNovember: Why frozen bloodworms should not be a staple axolotl food

Today, we’re kicking off #NomSafeNovember with one of the most frequently misused foods: frozen bloodworms.

Let's start at the beginning.

Axolotls are carnivores, or meat-eating animals whose nutrition and energy requirements are met by consuming animal tissues as food.

Okay, that makes sense.

Bloodworms, on the other hand, are the aquatic larva of the nonbiting midge (Chironomidae)—an insect that exists around the globe, similar to mosquitos in appearance, but without the annoying habit of biting.

So, if axolotls need to eat animal tissues (muscle, fat and other soft tissues) to sustain them, and bloodworms have soft tissues, then 𝐰𝐡𝐲 𝐚𝐫𝐞𝐧'𝐭 𝐛𝐥𝐨𝐨𝐝𝐰𝐨𝐫𝐦𝐬 𝐚 𝐠𝐨𝐨𝐝 𝐬𝐭𝐚𝐩𝐥𝐞 𝐟𝐨𝐨𝐝 𝐟𝐨𝐫 𝐚𝐧 𝐚𝐱𝐨𝐥𝐨𝐭𝐥?

The type of bloodworms most often recommended and sold by pet stores are either frozen or freeze dried. Although this means that they are readily available, inexpensive (at least compared to some other foods), and marketed as high in protein, neither the frozen or freeze-dried form of bloodworms are suitable as a staple part of the axolotl diet.

In their frozen form, bloodworms are rich in iron, but they contain only about 6-8% protein and don't contain many amino acids—both key requirements of the healthy axolotl diet. Don't be fooled by the packaging, either; a lot of frozen bloodworms claim to be a very high percentage of protein, but in reality bloodworms themselves contain about 6-8% protein, and each bloodworm cube contains 80% by dry volume. It's a tricky way to imply that you're feeding your animals a protein-rich food when, in fact, it's not.

What happens to axolotls that only eat frozen bloodworms?

Adult axolotls kept on a diet of frozen bloodworms alone are likely to become obese, which can lead to other health problems. Bloodworms are tastier than other healthier foods, so axolotls are much more likely to prefer the unhealthy option over nutritional options in favor of the taste.

Switching adult axolotls that are used to a diet of bloodworms onto healthier foods can often lead to hunger strikes, as well. Imagine being fed nothing but candy, only to be told one day that you're being switched to a veggie-only diet. You wouldn't exactly be thrilled about eating your new food, would you? (Note: In these situations, we recommend a tough love approach; it'll be hard, but don't give them bloodworms, even if they beg. We have a post coming later this month about weaning your axolotls off of bloodworms, so stay tuned if that's something you're currently struggling with or preparing to do...)

Axolotl hatchlings and juveniles fed a bloodworm-only diet are usually under weight and often pale. They also tend to develop at a slower rate than healthy axolotls, who grow about an inch a month once they hatch until they are full grown.

Poor nutrition can make axolotls of any age more susceptible to changes in their water quality. This can lead to frequent health problems like fungal and bacterial infections (stay tuned, we'll have posts on how to handle both of those, coming soon!).

Does this mean I shouldn’t feed my axolotl bloodworms?

Not at all! Bloodworms are a great infrequent treat for axolotls, other types of amphibians, and freshwater fish. Feed them in moderation, and switch up the treats you use so your axolotl doesn't start to favor a particular treat over other foods.

Other treat options include river shrimp, neocaridina shrimp, guppies, or platies (just remember: always quarantine any fish you intend to feed your axolotl, unless you raise them at home!).