Crayfish (aka crawfish or crawdads) are fascinating little creatures that eat many different foods. Their diet is broad and adaptable to nearly every aquatic environment you can imagine.
But exactly what do crayfish eat?
This guide will teach you all about the crayfish diet to help you gain a better understanding of these critters, and provide them with better care if you’re thinking about getting one.
What Do Crayfish Eat In Captivity?
Crayfish are opportunistic little creatures with a healthy appetite for just about anything!
Unlike some fish and even shrimp (although the latter is less common), crayfish are the opposite of picky. They’ll snack on whatever they can find!
Benefits They Bring To Your Tank
Because crayfish can eat so many different foods, there are a number of benefits that these little creatures can bring to your tank.
For starters, crayfish will also eat some of the things you don’t want in your aquarium.
They will readily consume many types of aquarium algae as well as bacteria. The decapods will eat away at algae that develop on the glass, decor, and any other surface in the aquarium.
Many of the 600-plus species of crayfish will also filter feed. They will filter the water and consume bacteria that would otherwise ruin the tank.
Their penchant for eating undesirables can do a lot to keep your aquarium clean and in good condition. They’re not going to replace your filtration system or regular maintenance duties, but you may notice your tank looking a little purer with crayfish in it!
In addition to eating things around the aquarium, crayfish will accept a wide variety of planned foods. As we mentioned earlier, they are not picky and will not stick their noses up at anything you provide.
You can give them dried food if you want. Due to their weak swimming abilities, sinking pellets are the preferred option. You might also see your crayfish eating any leftover fish flakes that sink to the bottom of the tank. This is a big plus, as leftover food is notorious for souring water conditions!
Additionally, crayfish will eat vegetables and protein-based snacks. Many aquarists like to provide small minnow fish or fry to give their crustacean something to hunt. Others will stick to commercial foods or prepared veggies.
Author Note: Whatever you decide to feed them, variety is key! Crayfish don’t get bored, per se. However, a bit of variety can ensure that they’re getting plenty of essential vitamins and minerals (as well as a little extra enrichment). In turn, their coloration and overall health can improve.
What To Watch Out For
So now you know what crayfish will eat when kept in an aquarium, and why that might be helpful.
However, there are some things you’ll need to consider before getting one. Interestingly enough, their ferocious appetite can quickly cause problems in a tank if you’re not prepared.
These decapods are fully capable of eating small, slow-moving fish. That means they can become a bit problematic if you stock your tank with daring fish that like to swim close to the crayfish. Those fish that can’t quickly dart out of the crustacean’s grasp will become food.
These creatures might even attempt to grab larger fish if they venture too close. However, they don’t do much damage to big fish. It’s the little ones you have to worry about!
On the bright side, crayfish aren’t particularly strong swimmers, so it’s easy to introduce them to community tanks with a bit of careful planning.
Author Note: That said, don’t be surprised if you find your crayfish snacking on a fish carcass. When these inverts see an opportunity to eat, they’ll seize it. Dead or diseased fish are not off the table.
Another potential issue with crayfish? Plants!
Crayfish love snacking on plants. Lush aquariums filled with greenery are great for most freshwater fish and invertebrates. But with the crayfish, you have to plan for some potential destruction.
More delicate vegetation will be no match for your crayfish. They will use their larger front claws as the first two pairs of walking legs to shred fine plants to bits!
Hardy and fast-growing plant species are tough enough to survive crayfish snacking. Some good examples include hornwort and Java fern, but anything else will get destroyed slowly as the crayfish feast. If you’re caring for a large colony of crayfish, those plants will be gone before you know it!
What Do Crayfish Eat In The Wild?
Crayfish come from pretty filthy environments. Typically, they inhabit streams and rivers. But unlike most fish, they’re not able to get up to the top of the water column. Instead, they stick to the muddy riverbed.
While these are not exactly prime living conditions for many aquatic creatures, it’s a great environment for crayfish. You see, their diet in the wild consists of primarily decaying matter. It’s the easiest food that they can source.
Fast currents that sweep dead plants and animals downstream. Using their claws, they grab onto anything that manages to flow by. This could be decomposing aquatic and land-based animals or decaying plants. By the time it reaches the crayfish, it’s usually soft and easy to tear apart.
Because of this, crayfish play an important role in its natural ecosystem. They’re part of the circle of life!
When they’re not consuming dead things, they will also scavenge for other items around their natural habitat. Rivers and streams are teeming with life. They’ll eat algae they find on twigs and rocks, plankton that’s floating around the water, and small fish they can quickly grab onto.
Crayfish aren’t strong swimmers. With a strong current working against them, the decapods are limited to whatever sinks to the bottom of the water column.
Luckily, there are plenty of things that end up there! Several creatures live down there along with the crayfish, too.
Many will also seek out worms, bugs, and tiny shrimp. Typically, crayfish have an abundance of food items to eat. But in particular dire times, these inverts may also cannibalize their own!
That behavior can occur in captivity, too (as mentioned in the section above). This means you need to make sure that your crayfish are always well-fed.
The Ideal Diet For Young Crayfish
You shouldn’t have too many issues finding suitable food options for your pet crayfish. But before you start planning their diet, you need to make sure they have a healthy environment where they can thrive.
Crayfish aren’t super demanding when it comes to decor or water conditions. However, they can’t be dramatically different than what they’re used to. Otherwise, you may see signs of stress.
These creatures can experience stress and anxiety just like humans. When they’re dropped into a strange new environment, many will have a hard time adapting. As a result, they avoid food! It’s very out of character, but it’s also more common than you would think.
Do your best to recreate a comfortable environment. Provide a nice layer of sand substrate that they can burrow in. Also, make sure that there are plenty of plants, rocks, and twigs. Crayfish need places to hide whenever they start getting anxious.
They’re fond of crevices and caves, so add those items to your aquarium to make things easier on your crayfish. Don’t forget about creating a small current as well.
Once you get the right living conditions, you can start experimenting with different foods.
Author Note: Remember that variety is important here. You’ll be hard-pressed to find a food that your crayfish doesn’t like, but don’t dwell too long on one food item. Mix things up for better results!
If you want to go the commercial route, you can use dry pellets. Shrimp pellets are a favorite among aquarists. They’re balanced, rich in vitamins, and sink down to the bottom of the aquarium for easy access!
You can also try algae wafers or dense protein-based snacks, such as frozen bloodworm blocks.
Speaking of protein, you have a lot of options here! Anything that you use on your fish is fine for your crayfish. Things like dried krill, mosquito larvae, and worms do well.
Many owners will also use their crayfish as decomposition machines. You can provide them with dead fish or shrimp from other tanks in your collection.
Avoid providing any diseased fish or those that died from parasitic infections. The last thing you want to do is spread the disease to your crayfish tank.
To give your crayfish a boost of vitamins, you can also give them some plant-based snacks. They will accept most vegetables. However, they are particularly fond of mashed peas, romaine lettuce, and small pieces of fruit.
Author Note: Remember how we said that their primary food source in the wild was decaying vegetation? Well, you can use that to your advantage in captivity, too. Give them any fresh vegetables that are starting to go bad, and these critters will get rid of them for you!
As you can see, there’s no shortage of things you can feed to your crayfish. Mix things up and provide tons of variety. Your crayfish will appreciate it!
Here’s a small list of food items you can add to your crayfish’s diet:
- Algae wafers
- Sinking pellets
- Shrimp food
- Standard fish food
- Mashed peas
- Frozen foods
- Brine shrimp
- Live fry or feeder fish
- Dry krill
- Small bits of fruit
- Blanched carrots
How Often Should You Feed Your Crayfish?
You don’t have to feed your crayfish massive amounts of food. They’ll eat in the tank throughout the day, so small meals are best.
As a good rule of thumb, provide pieces of food that are about three-quarters of an inch wide. Whether you’re providing pellets or cutting up small pieces of meat, that’s a good size for crayfish.
For newly born crayfish larvae, go a bit smaller. Provide food that’s about half an inch wide during their first couple of weeks of life. They grow up quickly, so it won’t take long for young crayfish to eat the larger chunks.
Juveniles and young crayfish can eat once a day. As they approach maturity, scale back to feeding them every other day.
Author Note: Don’t be alarmed if you see food sink to the bottom untouched. Crayfish are more active at night, so they often save substantial food for when they have more energy. Chances are, it’ll be gone by morning!
If they continue to ignore it, check water parameters to make sure that conditions are just right.
Aim to feed your crayfish the same amount of food, at the same time each day. These creatures are quite cunning and will pick up the routine. Once feeding time rolls around, they will start to come out of their hiding spots as they await your arrival!
If you’re someone who has always wanted to know what crayfish eat, we hope this extensive guide has answered your questions. In short, these creatures have quite a large diet and can eat pretty much any food they find.
Let us know if there are any foods we didn’t cover on this list that you’re considering feeding to your crayfish. It doesn’t hurt to double check if you’re unsure!