116 



The Ohio Journal of Science [Vol. XXI, No. 4, 



In the following table is given the relative importance of 

 each group for the six localities named above. The first column 

 under each group represents the total number of algal species 

 and varieties found in the fishes, and the second column gives 

 the total percentage content of the group for the particular 

 locality. The percentages are approximations based on the 

 total number of individuals present, not on the number of 

 species and varieties, belonging in each group. 



TABLE II. 



Number of species in, and percentage importance of, algal groups. The first 

 column gives number of species and varieties identified for the group; the 

 second, the total percentages of food content represented by these species. 



The filamentous algae were always present in small quan- 

 tities, if found at all, and no single plant was observed longer 

 than 300^1. It is easily seen how short, detached filaments 

 could enter the fish with the water of respiration. It was not 

 observed that the gizzard shad secured its food in any othpr 

 way. No material was found wadded up, either in the stomach 

 or the intestine, as is so often true among the game fishes. 

 In one shad the remains of some epidermal and palisade cells 

 of a leaf were found, but these may be considered as purely 

 accidental, ingested in the usual manner. 



It will be noted from Table I that the percentages of plant 

 food present in the digestive tract are very high and relatively 

 constant. Throughout the period during which the gizzard 

 shad is attaining a length of 7.5 centimeters, there is very little 

 change of diet. Nor does the diet appear to change materially 

 with greater age. An examination of two gizzard shad 

 twenty centimeters in length showed practically the same 

 proportion of microscopic alg£e found in the younger fishes, the 

 only variation being a slightly larger amount of unrecognizable 

 debris. 



