This article is based upon work done with the Australian redclaw crayfish, Cherax quadricarinatus.
Though all the precautions taken, may well work with other species of Cray, this is the only species i have had the opportunity to work with.
First thing you will need, is one Mature tank. my suggestion would be that it is of 40 or 50 ukg, minimum. add to that an established comminity, what fish you have is up to you. with the exception of large carnivorous fish, nothing else seems to cause problems from the fish end!
Next you will need a young Redclaw Cray, again age is not a problem, it is almost impossible to tell a Crays age anyway. size is no indication, there are no real, marking or colouration changes that go with age. So lets say a Cray of about 1 and 1/2 inches. You will need to put the cray in its own tank, again i would like to see the tank mature, however as the Cray will be on it own, the chances of that happening are slim, so i would suggest you clone your main community tank, so the water is atleast mostly cycled.
you will need to keep the Cray till it matures, in this tank. fear not however as Redclaw mature at about seven months. you will also have time to assess the disposition of the Cray you have. first off SEX, Redclaw males have a red patch on the outside if their claws, this will start to show as the cray nears maturity. Females have no additional colouring, but as it matures you will see the blue starting to creep up the claws with sucsessive moults.
it seems that Redclaw females, may have the best chance of living in communitys, however i know of a few males that do so.
things to look for as you assess your cray:
A Cray that hides all the time, may well turn out to be a problem, when you add fish, if its nervous on its own how will it act with company?
A cray that rushes at the glass when it see you, or anything else, may also be too aggressive for your aims.
IMHO what you need is a Cray that spends most of its time, in its hide, whilst still popping out when ever it feel like it. also feel that if your cray has a habit of dashing out to food, can also give you problems.
Its hard to quantify what your looking for here, but the term Chilled, actually sums up what you need to a tee!
Before you tip your cary in, a few words on feeding heating and filtration.
Heat firts. Redclaw are best kept at temps between 72 ahd 84 degrees. the higher end is the area that they would breed in. mine is kept at 78-9, which is also a good temp for many tropical fish!
filtration and feeding. an obvious thing to help stop predation, would be to keep you Cray well fed! this though seeming easy can give problems in itself, lots of food means lots of waste, both poo and uneaten food. unchecked this would be a real problem very soon. so vast over filtration is the order of the day, imo no bad thing on any tank. My filter is rated at 900 litres an hour, and the tank is 190 litres or so. as the advertised power of these things is often a bit over the top, i would say that you need filtration of 4 of five times the capacity of your tank.
still not ready to tip the Cray in yet.
hides caves nooks and cranny's. all of these are a must, both for your fish and your Cray. i would suggest you give at least three caves or hides, for your Cray, it will choose its favorite, but still clean the ones it does not use.
air stones and oxygen. Cray need well oxygenated water, so a spray bar would be a good addition. lots of air features go down well too, Cray tend to like sitting on an air stone, letting the bubbles flow over them.
hoods lights and escapes. you will need a hood that is totally secure, Cray make escape look easy, and will always take a chance and do a runner. light your tank as if it were for fish, though i would suggest a moonlight system, as Cray are very active at night.
ok now tip the Cray in. count how many fish you have, you will always do this, even in a tank where life for all is happy.
the next few days will tell if your feelings about your Cray were right. be aware though that Cray display more than they attack. it is not uncommon to see a Cray rushing down the tank with its claws above it head, seemingly chasing a fish. it is just making its claim to the tank floor, don't listen when people say Cray are not quick enough to catch some fish, piffle if your Cray wants a cory or a pleco, it is more than fast enough to do so.
if all goes well you are on the way to a community. please remember Crayfish are prone to Bacterial infection, constant adding of fish and inverts to the tank, may well turn out to cause more problems. this is the main reason for insisting on a mature community. and to add a bit of debate, i add tea tree oil to may tank on a regular basis, as yet i have had no illness, in over 14 months, and no signs of any bacterial action, except in the filter.
well I hope this helps those who have asked me to clear up my thoughts on Crayfish in the community!
regards BoB
Though all the precautions taken, may well work with other species of Cray, this is the only species i have had the opportunity to work with.
First thing you will need, is one Mature tank. my suggestion would be that it is of 40 or 50 ukg, minimum. add to that an established comminity, what fish you have is up to you. with the exception of large carnivorous fish, nothing else seems to cause problems from the fish end!
Next you will need a young Redclaw Cray, again age is not a problem, it is almost impossible to tell a Crays age anyway. size is no indication, there are no real, marking or colouration changes that go with age. So lets say a Cray of about 1 and 1/2 inches. You will need to put the cray in its own tank, again i would like to see the tank mature, however as the Cray will be on it own, the chances of that happening are slim, so i would suggest you clone your main community tank, so the water is atleast mostly cycled.
you will need to keep the Cray till it matures, in this tank. fear not however as Redclaw mature at about seven months. you will also have time to assess the disposition of the Cray you have. first off SEX, Redclaw males have a red patch on the outside if their claws, this will start to show as the cray nears maturity. Females have no additional colouring, but as it matures you will see the blue starting to creep up the claws with sucsessive moults.
it seems that Redclaw females, may have the best chance of living in communitys, however i know of a few males that do so.
things to look for as you assess your cray:
A Cray that hides all the time, may well turn out to be a problem, when you add fish, if its nervous on its own how will it act with company?
A cray that rushes at the glass when it see you, or anything else, may also be too aggressive for your aims.
IMHO what you need is a Cray that spends most of its time, in its hide, whilst still popping out when ever it feel like it. also feel that if your cray has a habit of dashing out to food, can also give you problems.
Its hard to quantify what your looking for here, but the term Chilled, actually sums up what you need to a tee!
Before you tip your cary in, a few words on feeding heating and filtration.
Heat firts. Redclaw are best kept at temps between 72 ahd 84 degrees. the higher end is the area that they would breed in. mine is kept at 78-9, which is also a good temp for many tropical fish!
filtration and feeding. an obvious thing to help stop predation, would be to keep you Cray well fed! this though seeming easy can give problems in itself, lots of food means lots of waste, both poo and uneaten food. unchecked this would be a real problem very soon. so vast over filtration is the order of the day, imo no bad thing on any tank. My filter is rated at 900 litres an hour, and the tank is 190 litres or so. as the advertised power of these things is often a bit over the top, i would say that you need filtration of 4 of five times the capacity of your tank.
still not ready to tip the Cray in yet.
hides caves nooks and cranny's. all of these are a must, both for your fish and your Cray. i would suggest you give at least three caves or hides, for your Cray, it will choose its favorite, but still clean the ones it does not use.
air stones and oxygen. Cray need well oxygenated water, so a spray bar would be a good addition. lots of air features go down well too, Cray tend to like sitting on an air stone, letting the bubbles flow over them.
hoods lights and escapes. you will need a hood that is totally secure, Cray make escape look easy, and will always take a chance and do a runner. light your tank as if it were for fish, though i would suggest a moonlight system, as Cray are very active at night.
ok now tip the Cray in. count how many fish you have, you will always do this, even in a tank where life for all is happy.
the next few days will tell if your feelings about your Cray were right. be aware though that Cray display more than they attack. it is not uncommon to see a Cray rushing down the tank with its claws above it head, seemingly chasing a fish. it is just making its claim to the tank floor, don't listen when people say Cray are not quick enough to catch some fish, piffle if your Cray wants a cory or a pleco, it is more than fast enough to do so.
if all goes well you are on the way to a community. please remember Crayfish are prone to Bacterial infection, constant adding of fish and inverts to the tank, may well turn out to cause more problems. this is the main reason for insisting on a mature community. and to add a bit of debate, i add tea tree oil to may tank on a regular basis, as yet i have had no illness, in over 14 months, and no signs of any bacterial action, except in the filter.
well I hope this helps those who have asked me to clear up my thoughts on Crayfish in the community!
regards BoB
