Correct Temperature for Catfish

Author: Ian Fuller

When it comes to what are the right temperatures to maintain certain fish at is something that creates an element of debate wherever fish keepers meet. This seems to be even more evident when the subject it catfish, or in my particular case where Corydoras catfish are concerned. For this particular discussion I would like to deal with some of the Corydoras species that prefer the cooler end of the so-called tropical scale. When we use the term tropical we are usually talking of temperatures around 75º Fahrenheit. Here we are talking about a temperature range considerably lower, at 60º to 70º Fahrenheit (15.5º - 21º Celsius).

There are four species in particular that would be very comfortable living at these lower temperatures. Two of them in fact become very uncomfortable and stressed if the temperatures rise much above 70° F. Dealing with these two first, they are closely related and resemble each other in colour pattern, in particular the females. They are Corydoras barbatus (Quoy & Gaimard, 1834), coming from fast flowing rivers that empty into Guanabara Bay in the State of Rio de Janeiro and Corydoras kronei A. de Miranda Ribeiro, 1907, which comes from the Rio Ribeira de Iguape basin São Paulo State. The third species is Corydoras macropterus Regan, 1913, which also comes from São Paulo State this species is a little more tolerant of higher temperatures but they will eventually start to suffer if maintained in warmer water for long periods. The forth species is Corydoras paleatus (Jenyns, 1842) originating from the Rio Paraná, north west of Buenos Aires in Argentina. All four species are found at least 22º South of the equator, in the case of Corydoras paleatus 33º South. The water temperatures in these areas fluctuate far more that we would imagine, with temperatures of below 60º F being regularly recorded.

My recommended set up for any of these four species would be a tank of at least 24 inches in length, with a thin layer of smooth grained sand (10 - 12mm), a few lumps of sandstone or other inert rock to create a few hiding places and give the illusion that you are looking at a sandy creek or a river bank. Two or three clumps of Java fern attached to pieces of bog wood will add a bit of colour and a few soaked Oak or Beach leaves scattered on the bottom, would give it that final authentic touch. For filtration I would recommend an outside canister type power filter, this will create good water movement, optimum filtration and they are very easy to maintain. I would only install a heater to combat extreme winter temperatures, if you live in an area that is free from winter frosts then I would not use a heater at all. The natural day night temperature fluctuation would actually be beneficial to all four species. The three species Corydoras barbatus, Corydoras kronei and Corydoras paleatus I have successfully spawned at 60º F. (15.5ºC) and in the case of Corydoras paleatus the lowest was 55° F.

In smaller tanks, 24-inch minimum, Corydoras barbatus and Corydoras kronei are best kept in pairs. If there are two males per female, which is the preferred ratio with most Corydoras species, there will certainly be squabbling, if not out and out serious fighting. The males of both species are territorial and become especially aggressive towards each other during the breeding season. Corydoras paleatus I have found are best kept in multiples of three, two males per female.

Corydoras macropterus, although a species that also enjoy the cooler temperatures, are not a fish for the inexperienced Corydoras keeper. They are a fish that inhabit Blackwater biotypes and require a little more water preparation. Soft and acid water is a term we have herd and read about for many years and is a requirement of many fishes. For Corydoras macropterus it is a requirement that should be observed if the fish are to be given a reasonable chance to breed. They will survive without to many problems in neutral water (7pH. 8º-10º GH) but are definitely at their best when the water is around 5-6 pH. 2º-3º GH. To help put some of the natural elements into the water I use pieces of soft bogwood and Oak leaves, which are allowed to leach their tannins into the water, this gives the water the appearance of weak tea. Regular water checks must be kept on the pH to make sure that it does not suddenly crash to dangerously low levels, which can happen very quickly in a small environment like a aquarium. The best way I have found to avoid such problems is by twice weekly 25% or 30% water changes. Rainwater filtered through moss peat is a good way of creating the right water conditions, providing of course, that there are no industrial contaminants in it. If it is found that the rainwater is not suitable through contamination, the mains water can be filtered through a water-purifying device and trace elements added to create exact parameters needed.

Corydoras macropterus males are territorial all the time and not just at breeding times, they are very aggressive towards each other, even when there is an abundance of females. In the past whenever I have attempted to keep these fish, let alone breed them, I have had trouble with males fighting and killing each other. The best method I have found to stop any serious damage from being caused is to slightly overcrowd them. For the last twelve months I've had a group of 6 males and 5 females in an 18 x 12 x 12 tank and so far there has been no harm done from their little squabbles. Because of the overcrowding I change 25% of their water every day. So far I have been unable to breed this species but I'm working on it.

Aquarium

Koi & Pond

Reptiles

Dogs

Small Animals

Cats

Birds

Books

Correct Temperature for Catfish

Other articles by Ian Fuller