94 EEPORT OF COMMISSIONER OF FISH A>;D FISHERIES. 



bodies at night, coming in-shore to feed and dispersing into deep water 

 in the morning. Mr. Simpson states that in spring and summer they 

 subsist principally upon mud and scum from the surface of the water, 

 ■which they obtain by feeding in muddy slues and channels on the ebb, 

 and grassy rivers and shoals on flood-tide. 



The examination of stomach-contents. 



121. The examination of the stomachs of a hundred or more menhaden, 

 just from the water, taken off Portland, Me., in Block Island Sound, at 

 the mouth of the Potomac, and in the Saint John's Eiver, Fla., has failed 

 to reveal any traces whatever of animal food. Mackerel examined at 

 the same time, in Maine, contained numerous specimens of " seed,'' 

 which were mostly a large entomostracan {Irenceus Pattersonii), and 

 small shrimp {Thysanopoda, sp.). Every menhaden stomach which I 

 have opened has been found full of a dark greenish or brownish mud or 

 silt such as is found near the mouths of rivers and on the bottom of 

 still bays and estuaries. When this mud is allowed to stand for a time 

 in clear water, the latter is slightly tinged with green, indicating the 

 presence of chlorophyl, perhaps derived from the green algse so com- 

 mon on muddy bottoms. A microscopic examination by Dr. Emil Bes- 

 sels brought to light, in addition to the particles of fine mud, a few com- 

 mon forms of diatoms.* 



Inferences from these examinations. 



122. Perhaps no decided opinion should be formed without additional 

 data, but the plain inference seems to be that the food of the menhaden, 

 in part at least, is the sediment which gathers upon the bottom of still, 

 protected bays, which is largely composed of organic matter, and upon 

 the vegetation which grows in such water. Upon what they feed dur- 

 ing their long sojourn at sea there are no sufficient grounds for conject- 

 ure, though it is quite possibly the soft gray ooze and mud which recent 

 explorations of the depths of the Atlantic have shown to exist at every 

 depth, and on the numerous protozoans and Bathyhins-Vike substances 

 there flourishing. The peculiar digestive organs of the menhaden were' 

 described in paragraph 53. 



Professor Verrill on bottom-mud. 



123. In remarks upon the characteristics of different deposits of mud, 

 Professor Verrill writes as follows : 



" In some cases, especially in well sheltered localities, where the water 

 is tolerably pure, the mud may contain large quantities of living and 



* "A larye uumber of specimens [of menhaden] freshly caught in seines were examined, 

 and all were found to have their stomachs filled with Zar^'c quantities of dark mud. 

 They undoubtedly swallow this mud for the sake of the microscopic animal and vege- 

 table organisms that it contains. Their complicated and capacious digestive appa- 

 ratus seems well adapted for this crude and bulky food." (Prof. A. E. Verrill, in Amer- 

 ican Naturalist, 1871.) 



