The following article was written by noted angling authority Fred Mather and published in Forest & Stream on 20 October 1900. It deals with what Mather considered a horrible idea -- the dilution of the trout species in America. With the recent stand that Trout Unlimited and other are taking against genetically modified trout, the issue is quite contemporary. It is refreshing to know that even 110 years ago, sportsman were willing to take a stand against trout "mules."
by Fred Mather
Dr. John D. Quackenbos has kindly sent to me the following letter on the subject of hybrid fishes from the Howietoun Fishery, Stirling, Scotland.
"We beg to acknowledge receipt of your most interesting letter in which you ask specially as to our experiment with hybrids. Most of these had no practical results, and since Dr. Day's death no fresh ones have been made. The only hybrids or crosses now at the fishery are the zebras, which are Made by meeting the ova of Loch Leven or Vario trout with fontinalis char. The progeny are finely marked, hence their name, but are very irregular in size, and subject to deformation.
We have a few ten year old fish up to 4 of 5 pounds in vveight, but they are quite barren. We have also the cross between the S. levenensis and. S. sailor. In the first cross there was a heavy loss in percentage of ova in hatching. The ova of the brood was again melted by S. levenensis, which made three-quarters trout and one-quarter salmon. The ova of this lot was again melted by S. levenensis, which made three-quarters trout and one-quarter salmon. The ova of this lot was again impregnated by S. levenensis, and this is the seven-eighths trout and one-eighth salmon mentioned in our price list.
There is not much perceptible difference between them and levenensis, only they are a little thicker and stronger on the whole, and in individual fish you can still trace some markings of Salmo salar. The late Sir James Maitland, the founder of the fishery, whose death was a great loss both to the fishery and to a much wider circle, took a keen interest in this cross. One can scarcely call them hybrids, as they are perfectly fertile.
There is no doubt that the introduction of fresh blood is often beneficial, but the important point is to make sure that the new blood is from mature parents and from a stock as good as or better than the native stock and of the same family. Dr. Day says: 'By judicious selection of breeders' races may be improved. The reverse is quite as true, that by an injudicious crossing of breeders, races may and will be degenerated."
Zebra trout were bred at Ringwood, N. J.. the estate of Hon. Abram S. Hewitt, and turned into the streams annually with no idea of their reproducing. They were a cross between the fario. brown trout, and fontinalis, our native brook trout. Mr. Edward Hewitt was of the opinion that they were earlier fish than the native trout, or than the brown trout, but I was not impressed with them, for I imagine I abhor a mule as much as nature abhors a vacuum. Ringwood is the only place that I have ever caught them, and perhaps, the only place where they were bred in this country. I say were bred, for they are bred there no longer. There are handsome fish for those who like zebras, and surely they do take the fly and fight above the water more than our native trout; but when they have had all the praise possible for beauty, and grace of movement, they are mutes, and either parent is a better fish.
Such crossings are well enough for scientists and experimenters, but the practical fish breeder should steer clear of mules as they are of no use in his business. The State of New York once went extensively into the mule business at one of the fish hatcheries, and when the stock of fish were bred to be ringed. strped and speckled, with marks of the short horn, Devon, Berkshire, Chester, white and Irish terriers, a merciful Providence intervened and destroyed the whole blooming outfit. Now the people get what they have a right to expect, straight goods, without a taint of of cross or any other monkey work. Nature is not in the mule business; it is man who is responsible for hybrids. There is fresh blood enough to be obtained from the same species of fish without going into collateral branches just to see how much the family can be mixed up and live.
-- Dr. Todd