34 ILLINOIS BIOLOGICAL MONOGRAPHS [34 



water plants and roots of trees that may extend out into the water. Thus 

 I have seen roots of willows so loaded with eggs that the roots themselves 

 were invisible. There is a very high mortality among the eggs, many of 

 them dying before gastrulation takes place. The young carp, like the old, 

 are gregarious, and often come up into the shallow waters along the shore. 

 I recall a school that tried to ascend the Oconomowoc river from La Belle. 

 In a single dip with a net twelve inches in diameter, I scooped out 291 carp. 

 Growth is rather slow; by the end of the first summer the fish are just 

 approaching four inches. The food consists of a tremendous amount of 

 bottom debris which is sucked in and the minute organisms strained out. 

 The fish bite readily usually on such bait as clam meat and put up a very 

 vigorous fight. A carp caught on a fly rod is about as good sport as one 

 could ask foT. As a food fish it is little used, though many of the 

 farmers "put them up sour" as they are not bad. However, the damage 

 they do outweighs their food value so far as local consumption goes, though 

 the commercial seiners, catching anywhere from five to fifteen or twenty 

 tons a year, make good money selling them outside of the state at eight 

 cents a pound. A determined effort should be made to rid the lakes of the 

 carp, and then to keep them out. This can be done if systematically 

 undertaken. 



22. Carassius auratus (Linn.). Goldfish. 



Although, of course, an aquarium fish, many goldfish have been 

 liberated in Oconomowoc and La Belle lakes, where they have established 

 themselves, reproducing in considerable numbers. Two schools of large 

 fish, weighing up to two pounds, exist in La Belle, and one school in 

 Oconomowoc lake. That the fish are breeding successfully is indicated by 

 the varying sizes of the individuals forming the schools, and by the presence 

 of individuals under three inches in length. They frequent the deep water 

 off the bars during most of the year, but spring (late April and early May) 

 finds them up in the shallows, where they are quite a sight for a few days. 



23. Campostoma anomalum (Raf.). Stone-roller. 



A very common minnow of the Ashippun, Bark, and Menomonee rivers, 

 with a few of the species found in almost any gravelly stream. They avoid 

 muddy or stagnant water entirely, being most abundant just under rapids 

 of clear water. They attain a size of five inches, rarely more, though the 

 average is not over four inches. In June the males of the species, in full 

 nuptial coloration and adorned with tubercles over the entire body, 

 can be seen carrying stones for the construction of the nest. Many small 

 pebbles measuring up to £ inch in diameter, are carried in the mouth 

 upstream to a clear gravel area and deposited in a pile eighteen inches in 

 circumference. In Bark river I have seen piles of nearly half a bushel 

 above the nest. The work is done entirely by the males and it would appear 

 that several work together on a single nest. The food consists entirely of 



