Why Your Crayfish Is Not Eating!

If you are keeping an aquarium and you have noticed that your crayfish is not eating, you might be feeling pretty concerned and not sure what to do about the situation. A crayfish is a beautiful addition to any tank and many people love them, but if yours randomly stops eating and you can’t figure out what’s wrong with it, you might be panicking. It’s always worrying when an animal stops behaving as you expect, but how much do you need to be concerned about a crayfish not eating?

It is fairly common for a crayfish not to eat for a few days or even about a week surrounding a molt, so if your crayfish hasn’t molted for some time, be aware of this possibility. Other things can also put a crayfish off its food and it’s important to be aware of these because you may need to change something about your tank setup if the parameters are off. Being aware of these things increases the chances of being able to solve a problem if there is one.

A crayfish not eating for more than a few days can be concerning, so you should pay attention to how your crayfish behaves and look out for things like loss of appetite. It can be difficult to diagnose problems sometimes, but having an idea about when your crayfish last fed and what its general behavior is will help you to pinpoint when something changes.

Why Is My Crayfish Not Eating?

There are many things that can cause a crayfish to refuse to eat, and the commonest tends to be the fact that it is preparing to molt; this means it will focus on building its new shell, rather than consuming nutrients for a few days or even around a week. However, this should not last for longer, and it should only occur every month or two for adult crayfish (although juveniles may molt every week or two). If your crayfish has only recently molted and seems to have gone off its food again, there may be a problem that you need to respond to.

You should test your water parameters to see if something has gone amiss with the levels of nitrates, nitrites, ammonia, or any other aspects of the water. Things like water temperature, iodine levels, calcium, and more can all make a difference to your crayfish’s willingness to eat, and if it seems to be off its food, you may want to run some tests on the water to see if something is out of balance.

It is also possible that your crayfish is bored of its current diet and wants something else to eat; you should try to vary what you offer and select different options for your crayfish. This may engage its interest and encourage it to try new things.

How Do I Get My Crayfish To Eat?

You can try to get your crayfish to eat in a few different ways, but the first and most important is by making sure that the tank exactly meets its requirements. If the water balances are wrong or something is causing the crayfish stress, it may not show any interest in food until these aspects are corrected. Make sure you regularly perform water changes and you test the water so you know if a level is getting out of balance, and then correct it if this occurs.

You may also be able to encourage your crayfish to eat by providing it with unusual foods and a good variety; crayfish can eat many different kinds of foods, including brine shrimps, daphnia, bloodworms, earthworm sticks, shell-on shrimps, zucchini, and more. Try a whole range of different foods to see what engages your crayfish’s interest, and bear in mind that those with a strong scent may be particularly attractive to the crayfish.

You should also make sure that the calcium levels of the water are high enough, particularly if you live in an area that has soft water; crayfish prefer hard water and may struggle if the levels are insufficient. You can add a cuttle bone to help correct this issue; it will calcify the surrounding water and gradually add minerals and calcium to the tank. You should also check that there are trace levels of zinc and copper.

How Long Can Crayfish Live Without Food?

A crayfish that has eaten well up until that point can usually survive for about a week once it stops eating, because it will have some food reserves to tap into, but it will not generally last for longer than this. If your crayfish is not eating, you don’t need to worry for the first days, as this is pretty normal, but as the timespan approaches a week, you may start to get concerned.

Keep testing your water parameters and encouraging your crayfish to eat by offering a range of different foods, and it will hopefully begin eating. You should worry less if you know the crayfish is about to molt, but do keep an eye on it and make sure it resumes eating once it has molted.

If you are thinking of going on vacation and you are worried about your crayfish not getting enough to eat, make sure you feed it well in the interim period, and then leave some food in the tank for it or have a friend or neighbor visit to feed it unless you will only be gone for a few days. Crayfish can’t survive for very long without food.


If your crayfish is not eating, it’s understandable to be worried, especially if you don’t think your crayfish is molting. You should test all the water parameters and make sure that your crayfish has enough of the crucial nutrients, and that the temperature is right for it. If you aren’t able to get your crayfish to eat, try tempting it with different foods, and choose ones that will create a lot of scent in the water so your crayfish is more likely to find them.