ON THE FOOD OP THE MENHADEN. 123 



material as it comes to them through the copepods, the various free-swiinining larvae, 

 and infusoria. 



Such being, then, the primitive character of the food supply of the menhaden, its 

 economic relations are very important; it arrives first hand at a food supply which is 

 the most stable, the most abundant and widely distributed of all foods, and yet so 

 unavailable to the great majority of other species. The wide distribution and vast 

 extent of the schools of this fish (which have been so remarkable in former years), 

 testify to this fact, for no matter how many are aggregated together in a given area 

 the food supply is adequate. At the same time the menhaden comes into no compe- 

 tition with the other food-fishes. In all the food products in the alimentary tracts of 

 specimens examined during the time named, not a trace of vertebrate tissue was 

 found; their presence does not threaten directly the life of any other vertebrate, nor 

 indirectly do they bring want to others by appropriating too much of their food supply. 

 In one instance this summer — at Hadley Harbor, Naushon Island — a small school of 

 menhaden was seen rising to the surface directly under a school of young " silver- 

 sides." The suddenness of the maneuver on the part of the former fish sent the 

 minnows leaping out of the water and scattering in all directions, just as when the 

 school is so invaded by enemies; as the silversides collected again, after a few 

 moments, at the surface, at a little distance from the former spot, the action was 

 repeated by the school of menhaden. A number of these latter were then captured 

 and examined, but in no case, of course, had the minnows themselves been taken as 

 food, while the large proportion of copepods in the stomachs of the menhaden would 

 indicate that they had found their prey located by the movements of these small 

 surface- feeding minnows. Their stomachs also contained, besides the usual quantity of 

 microorganic life, diatoms, infusoria, and the like, which are abundant in the brackish 

 waters of that beautiful and quiet retreat. 



Not only, therefore, do the menhaden not compete with other fishes for food, but 

 they themselves form an important factor in the food of other fishes, as has been so 

 often observed in the bluefish, bonito, and squeteague; making available through 

 their own life-history favorable conditions upon which the other economic fishes are 

 borne and satisfied; bringing to them directly an elaboration of this primitive food 

 supply here considered. To just what extent the menhaden are eaten by other food- 

 fishes has not yet been entered into in this investigation, but evidences of its impor- 

 tance as bait are everywhere at hand, and for this reason, if no other, its place is 

 an exceedingly important one in all questions involved in the study of hook-and-iine 

 fishing. The eagerness of the fishermen after menhaden for bait has been a most 

 constant feature of the expeditions made by us during the summer after the material 

 used in this study. One sees in the common opinion something more than a general 

 preference for such bait; it is a real necessity in their equipment for work. 



The relations of every individual organized being are so complex, the interaction of 

 its species upon others so intimate, that the life-history of every being must have a 

 very large circle of effects — visible and remote — not all of which may act in a directly 

 beneficial way for all of our immediate specialized wants. So it may be with the 

 menhaden, as with any other fish. In its method of gathering its food it does not, it is 

 true, come into competition with other fish, but the floating eggs and minute embryos 

 of all classes would be of a necessity swept in greater or less numbers into its mouth 

 in those surface waters which were supporting schools of menhaden. Large schools of 



