8 BULLETIN 649, U. S. DEPARTMENT OF AGRICULTURE. 



BUTTERFISH. 



Butterfish (Poronotus triacanthus) was chosen for one series of 

 studies as an excellent fish of the type commonly used as pan fish. 

 Butterfish occurs on the Atlantic and Gulf coasts from Maine to Texas, 

 and during the year 1915 the catch of the coastal fisheries of New 

 York and New Jersey amounted to over 5,000,000 pounds. At times 

 it is taken in such abundance that a glut in the market results, and, 

 since this fish is usually sold fresh, great quantities are wasted. The 

 butterfish which was studied in the experiments here reported was of 

 a good commercial grade, purchased in the local market, and it was 

 believed to be representative of this type of fish procured under the 

 ordinary trade conditions. 



The three subjects who assisted in the study of the digestibility of 

 butterfish, following the same routine which has hitherto proved en- 

 tirely satisfactory, ate an average of 105 grams of protein, 37 grams 

 of fat, and 208 grams of carbohydrates, daily, the fuel value of the 

 diet being 1,585 calories. The data obtained for the three-day test 

 period are included in the following table : 



Data of digestion experiments iviih butterfish in a simple mixed diet. 





Weight 

 of food. 



Constituents of foods. 



Experiment, subject, and diet. 



Water. 



Protein. 



Fat. 



Carbohy- 

 drates. 



Ash. 



Experiment No. 452, subject D. G. G.: 



Butterfish (in form of fish loaf) 



Grams. 



1,533.0 

 115. 

 322.0 



1, 259. 

 189.0 



Grams. 



1, 120. 9 

 86.8 

 22.2 



1,065.1 



Grams. 



303.7 



2.9 



26.1 



5.0 



Grams. 

 74.5 



0.1 

 43.1 



6.3 



Grams. 



Grams. 

 33.9 



Potato 



24.0 

 228.0 

 178.8 

 189.0 



1.2 



Crackers 



2.6 



Fruit 



3.8 

















Total food consumed 



3,418.0 

 46.0 



2, 295. 



337.7 



22.8 



314.9 



124.0 



7.5 



116.5 



619.8 



11.3 



608 5 



41.5 



Feces 



4.4 



Amount utilized 





37.1 











Per cent utilized 







93.2 



94.0 



98.2 



89.4 











Experiment No. 454, subject R. L. S.: 



Butterfish (in form of fish loaf) 



1,419.0 

 139.0 

 355. 



1,423.0 

 163 



1,037.6 



104.9 



24.5 



1,203 8 



281.1 

 3.5 



28.8 

 5.7 



69.0 

 0.1 



47.6 

 7.1 





31.3 



Potato 



29.1 

 251.3 

 202.1 

 163.0 



1.4 



Crackers 



2.8 



Fruit 



4.3 

















Total food consumed 



3,499.0 

 60.0 



2, 370. 8 



319.1 



24.9 



294.2 



123.8 



9.5 



114 3 



645.5 



16.5 



629.0 



39.8 



Feces 



9.1 



Amount utilized 





30.7 











Per cent utilized 







92.2 



92.3 



97.4 



77.1 











Experiment No. 455, subject 0. E. S.: 



Butterfish (in form of fish loaf) 



1,290.0 

 569.0 

 122.0 



1,474.0 

 196.0 



943.2 



429.6 



8.4 



1,247.0 



255.6 

 14.2 

 9.9 

 5.9 



62.7 

 0.6 



16.3 

 7.4 





28.5 



Potato 



118.9 



86.4 



209 3 



196. 



5.7 



Crackers 



1.0 



Fruit 



4.4 



Sugar 















Total food consumed ' 



3,651.0 

 68.0 



2,628.2 



285.6 



29.6 



256.0 



' 87.0 

 14.5 

 72.5 



610.6 



14.3 



596.3 



39.6 



Feces : 



9.6 



Amount utilized 





30.0 











Per cent utilized 







89.6 



83.3 



97.7 



75.8 











Average food consumed per subject per day 



1,174.2 



810.5 



104.7 



37.2 



208.4 



13.4 



