evolution of paste foods
Probably the first paste food was developed by Dr. Myron Gordon, an American geneticist who studied hereditary cancer in fishes. He worked mainly with swordtails and platies and so his formulation was blended towards livebearers. The formula he used was basically beef liver, pablum, shrimp and spinach. "Gordon's formula" was all the rage amongst hobbyists when it was first published in the late forties or early fifties - which was about the time when I started in the hobby. I remember grinding beef liver and canned shrimp in an old hand-cranked meat grinder. Then you cooked a bunch of spinach and ground it up too, making everything just as fine as you could. Next you stirred it all together in a large bowl, adding a cup or two of pablum. After it was well mixed it was packed in small jars and placed in a pan of water on the stove and brought to a boil for half an hour. It was removed when the food looked cooked. It was then allowed to cool a bit before the lids were put on. It was then stored in the refrigerator.
I used this formulation until the late sixties but then one day I was introduced to beef heart by Heli Kasza of Kitchener and I soon started on the beef heart formula. I trimmed the heart of fat and skin and ground it before running it through a blender. Also blended and added was cooked spinach or pablum. When well mixed it was frozen in flat plastic bags placed on a cookie sheet in the freezer. To feed it all you did was break off a piece and throw it into the fish tank. What a shortcut from the old "cook everything" method!
This remained my basic formula, which may have varied a little from time to time, almost until the nineties. During that time I traded in my old blender for a more powerful food processor. Then lo and behold came the Discus craze. All the world's experts were raving about turkey heart. Soon all of us "turkey" fish breeders followed suit. Now turkey heart is not necessarily better than beef heart but in Germany, where the idea originated, it was probably the cheapest meat available. I soon found that I could buy it on the Kitchener market at a reasonable price and so I proceeded to switch to a turkey heart formula. The hearts did not have to be skinned; there was only some fat and a few arteries to trim out. The only other change was the use of agar rather than gelatin in the water you have to add in order to mix everything in the food processor. Agar has to be boiled in water in order to dissolve it. Why agar? Unlike gelatin, it won't dissolve in a ninety degree discus tank!
Everything went well for a year or two. Then I started having trouble with angels as well as a few other fish. The fry would hatch, bloat, and die in a few days instead of becoming free-swimming on the seventh day. I tried different medications in the hatching water with no results. I blamed it on our city water which was as good a guess as any, until I decided it was a bacterium coming through from the parents. Treating the parents with an anti-bacterial medicine was the answer but the problem kept coming back. Where did the bacteria come from? I believe it came from the uncooked turkey heart. Which brings up the subject of to cook or not to cook.
Cooking destroys bacteria in meat but it also destroys some vitamins. I find it toughens the meat and it is unnatural for fish to eat cooked food. I have since switched back to beef heart and no longer have the bacteria problem, which more or less confirms my suspicions.
My present, 1999, formula is as follows. I start by cooking a bag of spinach. I leave enough water with it to make it blend fine in the food processor. Four beef hearts are cleaned of fat, skin and veins. It's then cubed and put in the food processor to chop and blend into a fine paste. You must add some water to do this. I dissolve a tablespoon of gelatin in two cups of hot water. Several of these "two cup cups" are usually needed. The gelatin binds blood and fine particles together. I also add two pounds of Alaskan pollock, a mild and inexpensive fish. A few multi-vitamin tabs are added and everything is mixed together in a very large bowl. Then, to make sure it's fine enough I run it all through the food processor one more time. I then pour it into metal cake pans to be frozen. A little water on the bottom of the pan after it's frozen will free it so that you can put it on a board and chop it into easy to handle blocks. I use a heavy, stiff-backed knife and a hammer. You could also use muffin tins.
As you might imagine, there is no exact formula. Some people claim spinach contains something that destroys vitamins. I have also used Romaine lettuce, Swiss Chard or beet tops from the garden. Instead of fish I've used shrimp, squid or canned tuna. Some Discus breeders even put in pears or bananas and one even kept quiet for years about putting in a few cloves of garlic. But beef heart is the base. What you add to formulate the food to suit the needs of the type of fish you raise, is up to you. But just remember that you "gotta have heart".
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