FOODS OF THE COMMON FISHES OF WINONA LAKE, IN 



KOSCIUSKO COUNTY, INDIANA, DURING THE 



MONTHS OF JUNE, JULY, AND AUGUST 



WILLIS DeRYKE 



INTRODUCTION 



In order to ascertain the kind of food utilized by the different common 

 fishes of Winona Lake during the summer months, and the important ecolog- 

 ical relations collections of fishes were made during the months of June, 

 July, and August of the years of 1919, 1920, and 1921. In all, thirty-five 

 collections were made and these from twenty-seven different locations on the 

 lake, each location presenting a particular type of environment. 



Two methods were used in securing the fish, the hook and line, and the 

 seine; more frequently the latter. Several unsuccessful attempts were made 

 to secure fishes from deep water by means of lines with hooks spaced at 

 three and four meter intervals. 



After a catch was made the stomachs of the large fish were removed im- 

 mediately and placed in ninety-five per cent alcohol. In removing the stomachs 

 care was taken not to lose the contents by the contraction of the muscular 

 walls of the stomach. Before severing the stomach from the intestine and 

 oesophagus, both ends were tied off with stout thread. The stomach was then 

 freed and plunged into ninety-five per cent alcohol where it remained until 

 examination could be made. The very large stomachs were injected with 

 ninety-five per cent alcohol by using a hypodermic needle. 



At the laboratory the stomachs were carefully opened and the contents 

 removed, placed in a watch crystal or small vessel and examination made 

 with a binocular microscope, the food then teased apart with needles or 

 washed apart by means of a pipette. The very small food was examined 

 under a compound microscope. The contents were identified as nearly as 

 possible and a count was made of the specimens of each kind present and 

 the number recorded. 



The fish were identified and measured in millimeters the length being 

 recorded as the distance from the tip of the nose to the base of the caudal 

 fin. After the examination of the fish and stomach contents, both were pre- 

 served for future reference. 



The Data 



The following are the data for the thirty-five collections. The collec- 

 tions are numbered and are located on the map by corresponding numbers. 

 Following the "date of the collection" the following seven points are always 

 given in this order; vegetation in the vicinity, character of the bottom, depth 

 of water, condition of water, weather conditions, time of day, and method of 

 taking. 



In each collection a species is named but once. Each individual is indi- 

 cated by its length in millimeters and this is followed by its stomach contents. 



(7) 



