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Yellowstone National Park
Yellowstone Park, Wyoming


Vol. XIV September-October, 1937 Nos. 9-10

This is one of a series of bulletins issued regularly for the information of those interested in the Natural History and History of Yellowstone National Park and the unmatched educational opportunities offered by this region. PUBLICATIONS USING THESE NOTES WILL PLEASE GIVE CREDIT TO "YELLOWSTONE NATURE NOTES" AND TO THE AUTHOR.

Edmund B. Rogers
William E. Kearns
C. Max Bauer

by Ranger Naturalist Harry Woodward

Common names have been applied to many types of our flora and fauna in such manner as to cause park visitors to become confused, particularly is this true of fishes and flowers. Speckled trout, mountain trout and salmon trout are the most frequently heard when reference is made to our most widespread species here in Yellowstone, the cutthroat (Saline lewisii). All of our trout are more or less speckled and those inhabiting mountain streams may be commonly termed mountain trout.

The pink flesh of the cutthroat caught at Fishing Bridge gives rise to many inquiries and no doubt leaves the impression with many that they may be properly termed "salmon trout."

It is true that salmon and trout belong to the same family, the Salmonoidea. Their common ancestor may have been a trout or a salmon or an ancestral type somewhat common to both, the Rhabdo fario facustris, such as has been brought from the Pliocene beds of Idaho, or the fossil salmonoid fish found in the Miocene of Bohemia.

The flesh color of most fishes, regardless of family, is white, flaky, and readily digestible and with a palatable flavor. Some fishes as the salmons and trouts, may have an orange hue because the flesh is charged with oil. This heavy oil bears the color. Others have a colorless oil which may be of a different constituency. It has been stated that some fishes with a dark red flesh contain an unusually heavy oil which becomes acrid and rancid when stale.1

The presence of this oil in the salmonoids is inherent. The body secretions in action upon the type of food eaten colors the natural oils. These pigments color the eggs at the expense of the muscles, and spawning fish will have a paler hue. This is especially true of the quinnat or king salmon whose rich salmon-red flesh becomes suddenly pale as the spawning season approaches.

The presence of oils with salmon-colored pigment, so noticeable in the salmon and the trouts, is noted in the charrs as well, and many times the Eastern Brook trout, which is a true charr, may bear salmon-colored flesh. This may depend upon the inheritance of the individual and the food. The Mackinaw or Lake trout (Cristovomer namaycush) is also allied to the charrs and a near relative to the Eastern Brook (Salvelinus fontinalis) but it bears a light oil and the flesh is white.

1. FISHES, David Starr Jordan, D. Appleton & Co., 1925, p. 129.


by James Simon

While collecting fishes on Falls River on September 9 and 10, we experienced great difficulty in taking Blobs (Cottus). Our problem was solved when we found that the Rainbow trout (Salmo shasta) there were feeding on them. By catching trout and taking blobs from their stomachs we made our collection complete. One ten-inch Rainbow trout from Falls River, when opened in the presence of District Ranger Tom Garry, yielded a blob (probably Cottus semiscaber) of five inches in length.

Other Rainbow trout caught yielded blobs from one to two inches in length.

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