18 BULLETIN 908, U. S. DEPARTMENT OF AGRICULTURE. 



classes copepods, which are approximately one-eighth inch long, as 

 macroscopic forms of sea life. 



2. Schizopods, 1 or "shrimp" (PL XI), are the larger macroscopical 

 forms on which the fish feed. 



Peedy Fish. 



Fish which have been feeding extensively on either of the two kinds 

 of food known to the fisherman as "red feed" and "shrimp" may be 

 designated as "feedy fish." While there is little difference in the 

 action of the two kinds of feed in rendering the fish unsuitable for 

 packing, fish that have been feeding upon "red feed" become broken 

 and deteriorate a little more rapidly than fish that have been feeding 

 on shrimp. Bacteriological examination of the feed showed that the 

 bacterium commonly associated with copepods grows faster and 

 produces a slightly greater amount of gas than the organism found 

 on the shrimp. 



" Feedy " fish, in so far as its influence on the quality of the sardines 

 is concerned, is perhaps the most troublesome factor in the sardine 

 industry. Fish more or less gorged with food deteriorate very 

 rapidly when taken from the water, while those having their digestive 

 tracts free from food remain in good condition for a comparatively 

 long time thereafter. As decomposition progresses the thin belly 

 portion of the fish gradully sloughs away, producing the characteristic 

 ragged appearance termed "belly blown." The rate of deterioration 

 depends upon the quantity of and the stage of digestion of the food 

 material contained in the digestive tract, and the bacteria accom- 

 panying it. Feed recently eaten appears to cause a greater degree 

 of deterioration than that which has been partially digested. Bac- 

 teriological studies have shown that the stomach portions of the 

 digestive tract are sterile when free from feed, even when digestion 

 in the intestines is incomplete. By the time feedy fish reach the 

 camiery they have deteriorated to such an extent and are so badly 

 broken that a large percentage is entirely unfit for packing. 



In the French sardine industry (27), where bait is employed in 

 catching the fish, the strictest attention is given to the quality of 

 the bait in order to avoid decomposition in the fish. As late as 1853 

 the use of a prepared bait containing especially powdered prawn and 

 shrimp was forbidden by royal decree, as it was held that it spoiled 

 the fish by facilitating decomposition. In this connection it is inter- 

 esting to note that the bacteria found associated with the feed (p. 24) 

 were capable of decomposing fish tissue. One of these organisms 

 forms spores which resist drying but are capable of growth and 

 reproduction when conditions again become favorable. The bait 

 mentioned, prepared from dried shrimp, doubtless contained the 



1 Identification of specimens made by the Division of Marine Invertebrates of the U. S. National 

 Museum. 



