Dwarf Crayfish: A Detailed Care Guide

Dwarf crayfish are the standard crayfish’s miniature cousins. Dwarf crayfish is an umbrella term for various tiny species, and the main difference between each species is their color and native region. Most types have similar behaviors and care needs.

Dwarf crayfish are fantastic aquarium cleaners, and they’re also significantly less aggressive than standard crayfish. They’re an excellent choice for aquarists who want to keep a crayfish in a tank with other fish.

In this article, I’ll explain everything you need to know about keeping dwarf crayfish in your aquarium, so you can decide if this fish species is right for you. Let’s get started! 

Dwarf Crayfish Species Profile

Below are the main characteristics of dwarf crayfish:

• Size: 1-2 inches (2-5 cm).
• Level of care: Medium.
• Environment: They prefer slow-moving freshwater.
• Ideal Temperature: 65°F to 75°F (18°C to 24°C).
• Wild habitat: Mexico and the southern US states.
• Lifespan: 1 to 3 years.
• Diet: Omnivorous.
• Sexual dimorphism: Females are smaller than males.
• Tank Size: Dwarf crayfish require at least 5 gallons (19 liters) per individual. 
• Place in tank: This fish species prefers to be at the bottom of the aquarium. 

There are some key differences between different dwarf crayfish species. The three most common dwarf crayfish in aquariums include the following: 

• Mexican dwarf crayfish 
• Cajun dwarf crayfish 
• Brazos dwarf crayfish

The preceding general species profile applies to all three species, and the following species profiles highlight each one’s unique attributes:

Mexican Dwarf Crayfish Species Profile

• Scientific name: Cambarellus patzcuarensis.
• Other names: Orange dwarf crayfish, Mexican crayfish, CPO crayfish, and Mexican mini-lobster.
• Color: Bright orange, rust-colored, or marbled.
• Average lifespan: 2 to 3 years.

Interesting facts about the Mexican dwarf crayfish:

• Wild individuals aren’t orange because humans have selectively bred their bright orange coloration for the aquarium trade. In the wild, they’re usually brown or rusty red.
• CPO (Cambarellus patzcuarensis var orange) refers to the selectively bred trait that gives them their orange coloration.
• Some orange individuals have been found in the wild, and these specimens are typically ancestors of selectively bred domesticated individuals. 
• Mexican dwarf crayfish are endangered in the wild. However, there are plenty of domestic individuals, making it unlikely that they’ll go extinct. 

Cajun Dwarf Crayfish Species Profile

• Scientific name: Cambarellus shufeldtii.
• Other names: North American dwarf crayfish and swamp dwarf crayfish.
• Color: Blue, brown, striped, or spotted.
• Average lifespan: 1 to 2 years.

Here are some interesting facts about this fish species:

• Cajun dwarf crayfish may change colors when they molt. Don’t be alarmed if your blue crayfish suddenly turns brown.
• Females typically live longer than males. However, there are always exceptions. 
• Wild Cajun dwarf crayfish are common. Their natural range is large, spanning most of the Gulf Coastal Plain. 
• Cajun dwarf crayfish love warm shallow water with plenty of vegetation. As a result, some wild specimens have been found in ditch puddles.

Brazos Dwarf Crayfish Species Profile

• Scientific name: Cambarellus texanus.
• Other names: Texan dwarf crayfish.
• Color: Blue, greenish-brown, olive green, or brown.
• Average lifespan: 1 to 2 years.

Below are some fascinating facts about Brazos dwarf crayfish:

• Their bodies are covered in tiny, freckle-like spots. However, these spots are easy to miss due to their small size.
• Male Brazos dwarf crayfish are exceptionally territorial. This isn’t typical behavior for dwarf crayfish. They’re still less aggressive than their larger cousins, but they’re more aggressive than other types of dwarf crayfish.
• Brazos dwarf crayfish are escape artists. Keep a firm, fitted lid on your aquarium, and don’t let the water line get too high.
• They’re primarily nocturnal (most crayfish are). Therefore, it’s normal if you don’t see your crayfish too often during the daytime. 

Behavior

Standard-sized crayfish will likely attack other fish in your aquarium. In contrast, dwarf crayfish are docile creatures that will leave the other fish alone. Many aquarists love them because they provide many of the advantages of a crayfish without the common downfalls.

Dwarf crayfish are surprisingly playful and interactive, and owners often say they’re a joy to watch. 

Dwarf crayfish frequently scuttle around the bottom of your tank, cleaning up waste products they can use for food. They may also raise their claws to interact with other fish or with you on the other side of the glass.

These little crayfish are full of personality, and aquarists have noticed that two dwarf crayfish of the same species may have different temperaments. They’re usually on the shyer side, but some individuals can be quite feisty and outgoing. 

Molting

On average, young dwarf crayfish molt 3 or 4 times a week, while adults molt much less frequently. Usually, an adult dwarf crayfish will molt approximately twice a year. However, molting frequency can vary between species. 

A molting crayfish will hide until its shell grows back. This behavior makes sense because they’re an easy target for predators without their protective shells, and they’ll instinctively hide until they can regrow new armor. 

If your crayfish disappears for a little while, molting may be the reason. Never force a molting crayfish out of its hiding spot, as a shell-free crayfish will feel stressed and unsafe out in the open. 

Leave your crayfish’s old shell in your tank because it will eat the old shell. This is normal and healthy crayfish behavior, and the old shells’ nutrients help them grow new ones. For this reason, you won’t need to feed your crayfish for a few days post-molt.

Unfortunately, molting can occasionally go wrong. When this happens, your crayfish might get stuck in their old shell and lie on their side, trying to bend their way out. Sadly, there’s not much you can do to help them. However, you can prevent failed molts by giving them adequate space and providing optimal tank conditions. 

The good news is that crayfish can survive failed molts, but it’s not comfortable. Taking the right preventative measures is better than taking a risk on a failed molt. You can also prevent molting failure by not moving them while they’re molting.

Dwarf Crayfish Care

For your dwarf crayfish to thrive in its aquarium, certain requirements must be met in terms of:

• Tank environment
• Diet
• Water
• Tank mates

I’ll discuss this in more detail below: 

Tank Environment

Dwarf crayfish need plenty of hiding spots, and it’s advisable to include plenty of rocks, driftwood, and aquatic ornaments they can use for shelter. Live plants are an excellent option but remember that dwarf crayfish are enthusiastic diggers and may uproot a live plant. 

Your substrate should be conducive to their digging. Sand, fine gravel, or small pellets are best but you should avoid chunky substrate because it won’t allow the crayfish to dig.

Dwarf crayfish love moss and won’t uproot it with their digging.

Ideal Diet

As omnivores, dwarf crayfish must eat plant and animal products to stay healthy. They’re also detritivorous and will eat organic waste from your other fish. 

Dwarf crayfish will eat algae build-up in your tank, making it easier for you to clean the tank.  

You can feed your dwarf crayfish any of the following foods:

• Algae wafers
• Sinking pellets
• Commercial invertebrate food
• Frozen veggies
• Brine shrimp
• Bloodworms
• Earthworms
• Mosquito larvae

If you opt for commercial food, make sure it’s intended for invertebrates, as standard commercial fish food may contain copper, which is toxic to crustaceans. 

Dwarf crayfish also need enough iodine in their diets because a deficiency can increase the risk of a failed molt.

Water Parameters

Dwarf crayfish can handle a wide range of water conditions. In the wild, they live in lakes or ditch water which shows that they aren’t overly picky. However, hard water can support healthy molt recovery, and pH levels can be fatal if too acidic.

The ideal pH and hardness levels for your dwarf crayfish are:

• pH: 6.0 to 8.0
• Hardness: 6 to 12 dKH

I recommend testing your water’s hardness at least once a month. This practice will benefit the other fish and aquatic plants, not just your crayfish. Hardness and pH are directly linked; maintaining one will help you maintain the other.

If you’re having trouble maintaining your water hardness, try adding a cuttlefish bone or crushed coral to the tank.

Tank Mates

Dwarf crayfish don’t need tank mates to be happy, but they can happily live with other fish species. One of the biggest advantages of dwarf crayfish is their ability to tolerate tank mates.

However, be mindful of the type of fish you add to your aquarium since some species are the 

dwarf crayfish’s natural predators. Dwarf crayfish won’t behave aggressively toward other fish, but they’re easy prey for some species.

Below are some fish species that make excellent tank mates for dwarf crayfish:

• Guppies
• Tetras
• Platies
• Hatchetfish
• Swordtails
• Mollys
• Danios
• Rasboras

If you already have dwarf crayfish in your aquarium, avoid introducing the following species:

• Shrimp: Dwarf crayfish eat shrimp and, unless you’re using shrimp as a food source, don’t keep them together. Larger shrimp species might be safe, but you should still exercise caution. 
• Snails: Like shrimp, dwarf crayfish eat snails. 
• Standard-sized crayfish: Dwarf crayfish are easy meals to their larger cousins.
• Cichlids: These fish will also make a meal from your dwarf crayfish. 
• Angelfish or other fish with long fins: These fish won’t eat your dwarf crayfish. However, your crayfish may nip or pinch their fins if they get in their way.

How Many Dwarf Crayfish Can You Keep Together? 

Generally, dwarf crayfish are docile. So, having more than one in your tank shouldn’t be a problem. Brazos dwarf crayfish are the exception to this rule as they tend to be territorial. 

You can keep one dwarf crayfish for every 5 gallons (19 liters) of tank water. If too many crayfish are kept together, they’ll compete for resources, starving some individuals. 

The 5-gallon (19-liter) rule is a general guideline because tank ornaments and other fish will also take up space. Most hobbyists recommend only keeping two or three individuals per tank, and it’s also perfectly fine to keep only one dwarf crayfish in your tank.

Reproduction

If you keep a male and female dwarf crayfish in the same tank, there’s a high chance that they’ll reproduce. Be mindful of your crayfish’s sex if you decide to keep more than one together.

How Do Dwarf Crayfish Reproduce?

A male dwarf crayfish deposits sperm into the female, who will store his sperm inside her body until she’s ready to lay eggs. For this reason, a female crayfish may seemingly have babies alone. Check your new crayfish’s history to avoid this situation.

Females usually lay 50-60 eggs in one laying, with eggs typically taking about 3-4 weeks to hatch. During the development period, the female stores her eggs beneath the end of her tail, where they’re wrapped in a layer of mucus for protection.

The new baby crayfish will stay tucked beneath the mother’s tail, and she’ll do all the work feeding and tending to them. You don’t need to provide any additional care for the babies. 

However, you may want to separate the little family until the babies are bigger because juvenile dwarf crayfish are more likely to be eaten by other fish.

Can Different Species of Dwarf Crayfish Interbreed?

All dwarf crayfish are from the genus Cambarellus. Therefore, they can crossbreed. Hybrid dwarf crayfish are available. The popular orange Mexican dwarf crayfish is a hybrid species.

Pairing two opposite-sex dwarf crayfish of different species may not prevent offspring.

How To Tell the Difference Between Male and Female Crayfish

If you want to breed your crayfish or avoid offspring, you’ll need to sex your crayfish. There are various ways to tell the difference between a male and female dwarf crayfish:

• Females are smaller than males.
• Males have a small, extra set of limbs (called pleopods) on their undersides.
• Females tend to have rounder abdomens.
• Male juveniles usually mature faster than females.

The problem with dwarf crayfish is that it can be difficult to notice their sexual dimorphism due to their small size. While females are smaller than males, the size difference may be so subtle that an untrained eye couldn’t notice it.

If reproduction concerns you, it’s best to ask your breeder about your crayfish’s sex.

Crayfish Plague

Dwarf crayfish are generally a healthy species with few species-specific ailments. However, like any crayfish, they can catch crayfish plague. 

Crayfish plague is a fungal infection that primarily affects wild North American crayfish. European and domestic crayfish are genetically close enough to catch the disease from their wild North American counterparts.

Fungal spores can spread in infected water. For this reason, prompt isolation is crucial. Remove potentially infected animals immediately to prevent infected water.

Unfortunately, you can’t help a crayfish with the plague. However, you should isolate an infected crayfish to prevent spread.

Prevention is the only way to protect your dwarf crayfish from crayfish plague. This involves only buying crayfish from reputable breeders and inspecting potential new additions for symptoms. Never introduce a wild-caught crayfish to your tank because it’s more likely to carry the disease. 

What Are the Symptoms of Crayfish Plague?

Keep a close eye on your crayfish if you notice the following symptoms:

• Nocturnal species becoming active during the day
• Imbalanced, stumbling, “drunken” movements
• Falling over and not getting up
• White spots on soft tissue
• Lack of response to stimuli
• Abnormal darkening of the shell (a darkened shell may also be a sign of molt)

Dwarf Crayfish FAQs

Conclusion

Dwarf crayfish are an excellent alternative to their standard-sized counterparts. Like standard crayfish, they’ll help keep your tank clean. Unlike standard crayfish, they won’t hurt your other fish or destroy aquatic plants.

The bright orange Mexican dwarf crayfish will beautify your tank. However, any species can be a welcome addition under the right conditions.