Need a pop of color in your nano tank?

The bright orange Cambarellus patzcuarensis, also known as the CPO crayfish, might be the perfect choice. This dwarf crayfish is pretty tiny, but its bright color and feisty personality make it a fun addition to your aquarium. 

Keep reading for everything you need to know about CPO crayfish care and keeping this dwarf crayfish in your aquarium!

Cambarellus patzcuarensis var. “Orange”, CPO crayfish (abbreviation of scientific name), Mexican dwarf crayfish, dwarf orange crayfish

CPO crayfish are naturally found in a few locations in Mexico. They actually lend their scientific name from Lake Pátzcuaro, one of the places where natural populations of these crayfish can be found.

Although CPO crayfish are naturally brown-grey in color, most specimens you’ll find in the aquarium trade today are selectively bred to be bright orange. As their name suggests these dwarf crayfish are quite tiny, with a maximum size of around 2″/5 cm.

Because of their size sexing these crayfish can be a bit of a challenge, but it can be done if you know what you’re looking for. Try to get a look at the underside of your CPO crayfish: males will have an extra set of modified pleopods under their walking legs, whereas females won’t.

Unlike most other crayfish, CPO’s stay small and don’t need a lot of room. You can keep them in aquariums of 8 gallons (30L) and up, which means they’re a great choice for nano setups that are a little too small for most fish. Just make sure the aquarium is filtered and fully cycled before you introduce any livestock. A heater isn’t absolutely necessary unless the ambient temperature tends to be unstable.

One important aspect of CPO crayfish care to keep in mind is that these are prey animals that molt regularly. This means they need plenty of hiding places to retreat to when they feel unsafe or are vulnerable after shedding their exoskeleton. Plenty of decorations are a must! The ideal crayfish tank has tubes or caves, rocks, driftwood and a nice layer of leaf litter. You can also add live plants, as CPO crayfish are too small to damage them like larger crayfish do.

Because CPO crayfish aren’t nearly as aggressive as many of their “cousins” there are plenty of options when it comes to tankmates. Almost all peaceful species that are suitable for your aquarium and like the same water values will work*. Even bottom feeders and fellow dwarf crays should usually be left alone. Just avoid anything that might have an appetite for crayfish, like (dwarf) cichlids and other carnivores.

*Some dwarf shrimp keepers have reported their CPO crayfish attempting to catch shrimp fry. I personally haven’t ever seen this happen, but you might want to skip CPO crays just in case if you keep expensive dwarf shrimp.

CPO crayfish are omnivorous scavengers, which means they’ll eat pretty much anything they come across. This makes them a great addition to your cleaning crew: they’ll clean up leftover fish foods, dead plant bits and much more. Supplement their diet and make sure they get enough calcium by regularly feeding specialized invert foods like this one.

If you’d like to add some variety to your crays’ diets you can try anything from frozen foods like bloodworms to fresh blanched veggies. Even leaf litter will be appreciated and eaten!

If you have no experience with breeding aquarium crayfish CPO’s are a great starter option because the fry and adults should tolerate each other as long as there are enough hiding places.

All you need to breed your CPO crayfish is a well-decorated aquarium and a healthy pair of crays. If all is well, the crayfish will handle the rest! Pregnant females will carry large amounts of eggs (up to 60, see photo below) between their swimmerettes, constantly supplying them with fresh air and picking off any bad ones. It can take up to five weeks for the fry to hatch and venture out on their own.

CPO crayfish fry don’t pass through a larval stage and can take care of themselves as soon as they leave mom’s protection. You might not see them much at first: they stay in hiding and feed on biofilm and other small bits until they’re large enough to fend for themselves at feeding time.

Although you might have some trouble finding wild-colored CPO crayfish, the orange version is widely available. Most aquarium stores carry CPO’s. If yours doesn’t there are also many reputable online sellers out there – you can buy CPO crayfish online at The Shrimp Farm!

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If you have any more questions about keeping Cambarellus patzcuarensis (CPO crayfish) or want to share your own experiences with these feisty orange inverts, don’t hesitate to leave a comment below!

Cover photo: IMG_3566 by captkodak

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Tired of searching for an aquarium snail that doesn’t produce babies by the hundreds? Nervous about Sulawesi snail care requirements?

The solution is here.

Faunus ater, also known as the black devil snail, is a large aquarium snail that doesn’t reproduce in freshwater. Also, it looks awesome! The ideal choice if you’re looking for an interesting aquarium snail that won’t overrun your tank with offspring and is easy to care for. 

Keep reading for everything you need to know about Faunus ater care and keeping this black devil snail in your own aquarium.

Faunus ater, black devil snail, black Faunus, lava snail

The Faunus ater snail is naturally found in the Western Indo-Pacific region, where it inhabits a wide range of islands. It can be found in all types of waters, including estuaries which can range from fully freshwater to mid-end brackish.

Faunus ater is definitely one of the more spectacular freshwater aquarium snails.

Its common name ‘black devil snail’ is derived from its black body. Its shell is also usually black, although there are also Faunus snails out there with brown shells and even ‘gradient’ shells (from black to orange to white). These are sometimes referred to as ‘cappuccino’. It’s unsure whether these are actually Faunus ater or another species in the Faunus genus.

Faunus ater looks similar to Sulawesi snails: both sport an elongated shell. In reality, Faunus snails are actually said to be more closely related to Malaysian trumpet snails. They grow to a maximum size of around 3.5″/9 cm.

What do you need to keep your Faunus ater snails happy and healthy?

Actually, not that much!

• Tank & equipment. Because these snails grow fairly large, you’ll need to go for an aquarium of at least around 10 gallons/38L. As with all fish and invertebrates a filter is needed to keep the tank cycled. Even though Faunus ater doesn’t like things too toasty, a heater is recommended to keep the temperature stable.
• Substrate Like some other snail species, Faunus ater likes to burrow from time to time. This means a sand substrate will be appreciated, although gravel will probably work too.
• Salinity. Interestingly, this snail is actually not strictly freshwater! If you’re setting up a brackish tank for peaceful fish like bumblebee gobies, you can consider Faunus ater as a tankmate. Some sources report Faunus snails being kept at a salinity up to full marine succesfully.
• Decor. Although not all aquarists seem to have trouble with their Faunus ater snails munching on plants, some do report damage. This means it might be wise to avoid these snails in aquascapes or tanks with expensive and rare plants. Some hiding places are probably appreciated, though, so try a few cheap plants and/or rocks and driftwood.

When it comes to tankmates, Faunus ater snails aren’t fussy.

As can be seen in the video above, they are a great choice for super-peaceful setups with dwarf shrimp like red cherries and other vulnerable tankmates. This way, there won’t be any nippy fish to damage the snails’ fragile antennae and even the tiniest shrimp will be left alone. Be sure to keep at least two of these snails, as they do love company. No need to worry about snail babies!

If you do want to keep your Faunus ater snails with larger and more active fish, try to avoid any active hunters. Species that love a very low pH value and soft water don’t make a great choice either.

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Like many other aquarium snails, Faunus ater snails are omnivores that will eat pretty much anything they come across.

Any leftover fish foods will happily be consumed, and the same thing goes for dead (or even live) plant bits. Algae is also a favorite, so your Faunus snails will appreciate it if you leave some in the tank.

Because most of our aquariums are a little too ‘clean’ to sustain a few of these snails you’ll need to supplement their diet. Use an invertebrate food that contains plenty of calcium to ensure proper growth; I’ve found high-quality shrimp foods (like the appropriately named ‘Frenzy’ food) work well. Other than that, anything goes. Blanched fresh veggies, algae tabs, regular fish food and even frozen foods will all be devoured.

This snail behaves exactly as you would expect a snail to, with one big difference.

They are fast.

If you’re looking for an active snail that spends a lot of its time zooming around the tank in search of algae, Faunus ater is a great choice. They are actually reported to be a more active than their Sulawesi cousins and certainly cover more distance!

Breeding Faunus ater snails is not an easy task. This means no risk of a baby explosion, but unfortunately also no way to ensure a steady supply of snails.

Although not much seems to be known yet, it’s suspected that breeding happens in brackish water.

Although Faunus ater snails definitely aren’t as widely spread in the aquarium hobby as some other snail species, you might be able to find them at your local aquarium store. You can also easily order them online from Amazon here!

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