Starting with Corys

Before considering keeping any species of Corydoras, whether they are common or rare there are a few things to that need to be looked at, and a few questions to be asked.
Firstly and the most important item of consideration is the environment in which they are to be housed. Most Corydoras species will live quite happily in a relatively small aquarium, a single pair of fish in a 25 cm x 20 cm x 20 cm (12 x 8”x 8”) tank would do fine, but if you want to give them some company! Say another three or four mates of the same species and a few tetra’s or Barbs, then larger surroundings would be a must, a tank of 60 cm x 30 cm x 60 cm (24”x 12”x12”) would be a good size to start with. The equipment and decoration to a certain degree is all a matter of choice, but there are some area’s that should be given careful consideration, the main one of these is the substrate that is to be used. My recommendation is the use of fine smooth gravel or a course grained smooth sand, to a maximum depth of 15 millimetres this allows the catfishes to reach through to the base glass of the tank and find all the particles of food that have penetrated deep into the substrate. I emphasise the smooth because this is extremely important when it comes to keeping Corydoras in the best of health and condition. Any sharp edged sand or gravel can very quickly damage the delicate barbels of these busy little fishes, this damage in turn can lead to bacterial infection and fugal attack which may in turn be fatal.
The second major consideration must be the filtration system to be used, and because of the fine ness of the substrate an under gravel system would soon become choked with debris, for this reason I would suggest one of the following methods. The first are simple internal air driven sponge or box type filters that are ideal for small breeding or fry rearing tanks, these are driven using a small diaphragm pump. The sponge filters are particularly good in fry tanks because fry cannot be drawn into them Both of these type of filters comes in a range of sizes and are very easy to maintain. The second type of filters are the internal canister variety which are electrically powered, they are all designed and made to house all the necessary filter elements to be able to adequately filter a given amount of water per hour. Again these come in a variety of sizes and designs to suite both your needs and your pocket. The third type of filter is of the external canister type, which can be the most expensive, but they are also the most versatile in as much as they can be maintained simply and without disturbing the contents or inhabitants of the tank. These types of filters also come in a range of shapes, sizes and capacities to suit all sizes of tanks.
Lighting is also a thing of personal preference, but one thing to remember is that Corydoras are bottom dwelling fish and therefore would not generally be exposed to bright light. If the tank that Corydoras are to be housed in were to be a community type tank and part of the furniture, then I would recommend it to furnished with a reasonable amount of plants both terrestrial and floating. Other considerations that need to be looked at are to a degree purely personal; especially when it comes to tank furnishings, tank mates, or even the species of Corydoras you would like to keep. There are many species to choose from, with probably as many as fifty species available at any one time through out the country.
The final and most important thing to consider is the health and quality of the fish you are looking at buying, here some important pointers to help choose good healthy fish.

Bad points to look for when buying Corydoras.

1) Worn or no barbels, 2) Sunken eyes, 3) Reddened gills, 4) Hollow / pinched body, 5) Pinched/ clamped fins, 6) Ignore any fish with deformities.
Fish having any of the above conditions should be avoided.

Good points to look for when buying Corydoras.

1) Active, 2) Good barbels, 3) Bright eyes, 4) Plump body, 5) Fins held erect.

The feeding of Corydoras is in itself is a fairly simple task and the choices of foods are almost endless. Most of all the commercially manufactured flake and tablet food are very good, the flake types foods however should be held in the surface water momentarily until it has become soaked then released, this is to ensure that it will sink to the bottom straight away making sure that the Corydoras get their food and that the flake does not stay on the surface, only to be eaten by the other tank mates with very little getting to the bottom for the catfish. All of the tablet foods that I have used sink straight to the bottom and are quickly found by the Corydoras and consumed. The only foods that I would offer a word of caution with are the high protein compressed granular types; these come in various grades and should only be given in small amounts. If the granules are small enough for the Corydoras to swallow whole, then there is a danger that the granules are eaten before they have had time to swell up with water, this then happens within the gut of the fish which can then cause serious problems with the fishes digestive system, the result of which can and is often fatal. If on the other hand granules are fed that are to large for the fishes to swallow whole, but allow them to mouth them as they dissolve then there is seldom a problem. More recently there have been granulated foods manufactured especially for catfish that do not swell as they soak up water.
Live foods are excellent for conditioning potential breeding stock, or to help keep your fish in tiptop condition but they are not always available. When live foods are scarce or unavailable there are a wide range of commercially prepared frozen foods on the market these include; Daphnia, Tubifex, Bloodworm, Cyclops, Gnat larva and Brine shrimp (Artemia). Another exceptionally good alternative and it’s free are finely chopped earth worms, they will bring Corydoras into breeding condition and enhance the fishes colours quicker than anything else I know.
Corydoras will eat almost anything offered to them, but a good tip to remember is that it is always better to under feed than to over feed, this will help to ensure that the tank does not get fouled with rotting uneaten food.


Pictures: -

1. Bad barbels 2. Sunken eyes 3. Deformities
4. Good barbels 5. Good fins 6. Quality fish
7.8.9.10. = Pics of species choice