18 FISHES OF ILLINOIS 



shovel-fish or shovel-cat, duck-bill cat, and spade-fish. Per- 

 haps the earliest mention of the paddle-fish is by Pere Mar- 

 quette (1673-1677), who described it as a remarkable fish, re- 

 sembling a trout with a large mouth. " Near its nose * * is 

 a large bone shaped like a woman's busk, three fingers wide and 

 a cubit long, at the end of which is a disk as wide as one's hand. " 

 Jesuit Relations, LIX., p. 111. Edition Thwaites. 



Although the paddle-fish frequents waters with a muddy 

 bottom, the relatively minute size of many of the objects on 

 which it feeds, the absence of mud from its intestine, and its 

 seeming preference for an'mal food, indicate that it is not only 

 able to gather large quantities of very minute objects from 

 among the weeds and from the muddy bottom, without filling 

 itself with mud, but that it can separate the Entomostraca from 

 the algae among which they swim. 



The facts concerning the food of this fish were first ascer- 

 tained and published by the senior author in 1878,* and were 

 studied again more extensively by him in 1888.f The paddle- 

 fish is generally supposed by fishermen to live on the slime and 

 mud of the river bottom, an idea confirmed at first sight by the 

 general appearance of the contents of the alimentary canal, 

 which are commonly a dark brownish semi-fluid mass resem- 

 bling mud, but which, when placed under a microscope, are seen 

 to be made up largely of countless myriads of Entomostraca of 

 nearly every form known to occur in our waters. Mixed with 

 these in varying proportion, often, indeed, predominating, are 

 soft-bodied aquatic insect larvae, chiefly those of day-flies, 

 dragon-flies, and gnats (Chironomus) , and a smaller percentage 

 of adult aquatic insects, amphipod crustaceans, leeches, and 

 water-worms (Naidoe), to which are added, in some cases, con- 

 siderable quantities of aquatic vegetation, largely algae, but in- 

 cluding likewise fragments of various aquatic plants. In the 

 food of eight specimens, obtained from Peoria, Pekin, and Henry, 

 on the Illinois, from the Ohio at Cairo, and from the Mississippi 

 at Quincy, in six years between 1877 and 1887, no fishes or 

 mollusks were found; but insects and crustaceans the latter 

 mainly Entomostraca made by far the larger part of the food, 

 the insects being taken by all the specimens and in nearly twice 

 the ratio of the crustaceans, neuropterous larvae of day-flies 

 (Hexagenid) alone amounting to 47 per cent. As these are com- 



* Bull. 111. State Lab. Nat. Hist., Vol. I., p. 82. 

 f Ibid., Vol. II., pp. 464-467. 



