Article © Kaycy Ruffer, uploaded January 01, 2002.
The Pygmy Cory (Corydoras pygmaeus Knaack, 1966) was discovered in Brazil where it comes from the Rio Madeira and its tributaries.
These fish reach a length of about one inch in total length. They are a silvery-white with one very black unbroken horizontal line that starts at the tip of it's nose to the caudal peduncle. There is another line along the lower part of the body from just behind the ventral fins into the tail. Across the top portion of the body is a lighter black region that starts at the tip of the nose and continues along both sides of the upper body and ending at the tail.
I first started spawning these little wonders in 1988. I set them up in a ten gallon tank with an inch of fine sand, plastic plants and a sponge filter. I put 10 mature fish in the tank and fed them with live baby brine shrimp and ground basic flake food. I left the spawning group in this tank for about a week and then moved them to another ten gallon I had set up for them. If I remember correctly, I got over 200 fry in that one weeks spawning! After hatching, the fry eat the microscopic organisms in the sand for the first week. When I saw the fry swimming around in the tank I started adding newly hatched brine shrimp and then when they were about a quarter of an inch in length, I started adding small amounts of finely ground basic flake food. Once the fish grew up from the second tank of spawning, I put the group into a 55 gallon community tank to prevent any further spawnings. (I know they continued to spawn, but the eggs were eaten and I wasn't eaten out of house and home by these guys!)
Now, in 1994, I have seven pygmaeus left from my original spawns and as far as I know, all males. On February 8th, I decided to rearrange my living room to accommodate a couple of 2'x 2' rearing flats. As I started netting the fish out of the tank, consisting of: 2 Melanotaenia boesemani rainbows, 2 baby Gold Gouramis, the 7 "male" pygmaeus, and 5 baby Bristlenose plecos, I saw something flash across the front glass. I was thrown! I knew I had babies in the three gallon tank but, I also knew there were not any that small! I caught the larger fry first, since they would be the easiest to catch. Then I started catching these little mysteries. As I looked at them in a glass bowl I realized they were pygmaeus fry! It took me a few minutes to realize that I did indeed have a FEMALE!
I moved this breeding group into a ten gallon tank with a sponge filter and fed baby brine shrimp and tubifex worms. One thing to remember when feeding pygmaeus corys is they have very small mouths. So, keep this in mind whenever you feed, it must not be too large. After their first spawn, in which eggs were placed everywhere, I had the brainy idea of placing one of my Rainbow spawning mops into the aquarium. I hoped it would be easier for collecting eggs. It would be easier to collect the eggs off the mop than off the glass and everything else in the tank.
It worked! 90% or more of the eggs were placed on the glass. You might say, that I wanted them to lay the eggs in the mop? But, guess where they laid these eggs? Right behind the spawning mop! After I stripped the mops I placed the eggs into a small (three inch) white shrimp net. The eggs are quite tiny. After the fry hatch I siphon the babies with a regular air line tube and release them into the tank set-up only for the pygmaeus fry. I placed one layer of gravel on the bottom (I learned a long time ago that these little guys eat the minute organisms found in the gravel bed as their first food.)
As they get older, to a size where you could see them scooting about easily, I would feed them my ground Spirulina 20 Sinking Pellets with dried Brine Shrimp Cubes. I add a pinch of this blend to some water and really stir it up. After it settles I use a syringe to siphon ONLY the top portion of the water. Now you have you're very own liquid food! The mixture has several sizes contained in the liquid. As the fry grow, use the next level of water. Once your fry are taking the third level you can begin feeding newly hatched brine shrimp. I switch between brine shrimp and the mixture each day. You will be able to tell when your fry are large enough for newly hatched brine. The newly hatched fry have vertical stripes on their bodies. As they get older the stripes seem to disappear. At about one month old the vertical stripes are completely gone and the horizontal stripe of the parents appear.
These are a schooling fish and do not do well by themselves. Do keep them in groups of 12 or more. For spawning, use at least one female to six males. It's possible your fry will be ready for spawning at 3-4 months of age. You can tell the female from the males by looking at them from the top. (That's if the female is mature). The females will be wider than the males.
These are a great species to keep in a small tank with other small fish of the same size and temperament. I would recommend Heterandria formosa livebearers or Poecilia sp. Endler's livebearers. In a tank of appropriate size (twenty gallons) having this combination and differing coloration, they would make a fantastic conversational show piece!
There is further information on this species on the Cat-eLog page.
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