by Raphael Bornemeier
In my tanks, there are various crayfish species.
However, today I’d like to talk about Cherax cf. monticola. This is a species seldom found in literature, and pictures are even harder to come by. What kind of crayfish is it then, this cf. monticola? It’s anatomy is that of a common Cherax, a Papuan/Indonesian crayfish.
What’s their color? Well, that’s not an easy question to answer … C. monticola are, let’s say, a bit more colour-happy and do not limit themselves to just one. They come in brown, in red and in blue hues that can go to an intensive midnight blue.
Social behavior: As I have several crayfish of the genus I can rightfully say that the monticola are quite special. When I got the two juvenile crays, the tank was all quiet. However, after two days, the two of them were walking across the tank together – I would not go as far and say claw to claw, but they indeed looked a bit like they were holding hands.
And now, only 4 weeks later … what can I say. She is berried, and he does not leave her for a minute. They sit in their cave together, and if one of them happens to leave the „hut“, the other one follows immediately. The eggs are two-colored, and everything looks like they will be breeding successfully.
In my tanks, the crays live together with shrimp. I have not seen any deaths so far, and the crayfish also leave my plants alone. However, crayfish are animals with lots of character, and I don’t want to generalize. My crayfish don’t burrow either, however, tank decoration needs to be stable should they decide to dig a hole.
Let’s have a closer look at the tank now: As crayfish do not swim much I considered my first tank a real waste of space. When I went to my aquarium manufacturer, I got the idea of having tanks tailored to the requirements of my crayfish. They are now 80 cm long, 45 cm deep and only 25 cm high. As these crayfish have an adult size of 10 to 12 cm (without the claws), the footprint of the tank needs to be at least 80 cm * 40 cm. The base of the tank is decisive when you keep crayfish. In many descriptions, the volume of the tank is given, however, this is only a makeshift hint at the tank size, nothing more. A tank that just covers the basic requirements can hold only one pair of these crayfish, as a maximum.
Lighting: In theory, you can completely forget about lighting for these crepuscular to noctural crayfish, as they are not active during the day. When the lights are out they leave’ll their cover.
Food: I add JBL Novo Crabs to their usual staple diet of brown fallen leaves. Crayfish are omnivores, and I think that if they are in a social tank with fish they might start hunting if their protein hunger gets too big.
Recommended water parameters:
Water temperature: 20 to 24 °C, does not like cooler waters
GH: up to 25
KH: up to 25
In my crayfish tanks I mix Black Water Powder into the changing water, and a small pinch of a mineral powder consisting of: powdered mussel, Na + Ca carbonate, calcium, and further trace elements. Bonding agent: E 558 bentonite-montmorillonite
I have not had any crayfish with molting problems since I use this combination. It may not be a miracle-worker, however, it does not do any harm either.