212 REPORT OF THE COMMISSIONERS OF 



somewhat after the manner of the toothed jaws of a steel trap. Such an arrangement 

 is especially effective in working the center of the wound deeper. The teeth are placed 

 in such a circular radial position (see illustration of mouth of Lake Lamprey) that all 

 solid parts (skin, scales, flesh, etc.) are worked to the center of the mouth and then 

 ventrad or downward and out at the ventral margin. Since the lamprey swallows no 

 solids whatever, it is essential that they should have some such provision for the elimi- 

 nation of the waste material or solids which result from tearing through their victims. 



We have often seen wounds which completely penetrated the body cavity, and 

 through which the internal organs had been attacked. Wounds are shown piercing 

 the heart in the third and fifth specimens from the left in the illustration of "Eight 

 Bullheads," and from the second and sixth specimens of the same illustration the 

 intestines were protruding whe$ collected and photographed. We had a specimen in 

 which the stomach was pierced, and in an aquarium all the food given it escaped 

 through the orifice in its side. The fact that bullheads are dressed before being 

 exposed for sale enables thousands of pounds of them to be retailed which would not 

 otherwise find purchasers. The great festering sores in the flesh of the fishes as they 

 come from the water render them so repulsive in appearance that no one would want 

 to purchase them in that condition, but when the fish are dressed such wounds are not 

 conspicuous. 



A fish that has been attacked by a lamprey, if not killed at once, becomes bloodless, 

 thin, pale and colorless both as to skin and flesh, and insipid to the taste. Naturally a 

 strong, healthy fish has a rich golden tinge, but when attacked by a lamprey its color 

 and appearance are so altered that we have been able to readily identify those that 

 were injured, while yet alive, by merely observing them, after an assistant had spread 

 the entire catch on the bank and turned the sides bearing the scars downward so that no 

 marks would be visible. It is true that the wounds often become healed, but scars 

 remain, and with the scale-bearing fishes these wounds are generally quite conspicuous 

 on account of the very irregular arrangement of the scales that grow over them. If 

 the attacks do not prove directly fatal they generally become the sites for the 

 sarcophagus fungus to start, and from this cause death may soon ensue during any 

 time of the year when the water is warm; or they weaken the fish and destroy its 

 vitality, reducing its reproductive capabilities and often preventing it altogether 

 from reproducing. Also, by the removal of the blood the flesh is left white and 

 insipid or tasteless and really unfit food for man. 



Our collecting records show that at the height of the feeding season fully eighty- 

 four per cent, of all fishes that are large enough are thus injured. We have no doubt 

 that in this region the lampreys destroy more fish than do all the other enemies of fish 

 or all of the fishermen combined: 



