68 INLAND FISHERIES. 



XV. What are the natural enemies of the starfish f 



The destructive agents and natural enemies referred to in the 

 hist report were cokl and fresh water, various fishes which feed 

 upon the larvfe, gulls and crows, and parasites. 



Some of the specimens which were being attacked by the 

 parasite frequently found in the fall of 1897 were kept over winter, 

 and by spring the disease had disappeared. The effects of the 

 disease were visible, however, in some cases. In one starfish an 

 arm was entirely eaten through, about f inch from the tip, but 

 was not thrown off. The stump healed over, and the star was 

 kept throughout the year and is probably still alive. It showed 

 almost no trace of regeneration, probably from the fact that food 

 was rarely taken by the specimen. 



The enemy which is doubtless the most destructive to the star- 

 fish is the menhaden. In an article on the " Food of the Men- 

 haden," published in the United States Fish Commission Bulletin, 

 XIII, 1893, Dr. James I. Peck showed that this fish feeds ex- 

 clusively upon the minute organisms which swim or float free in 

 the water. The open mouth of the menhaden has an area of about 

 one square inch, and as the fish swims through the water with 

 open mouth and gill covers raised, a considerable column of water 

 is passed through the mouth every minute (estimated by Dr. Peck 

 at about seven gallons). The gillrakers strain the water, and the 

 organisms which are not too minute are caught in the mouth and 

 swallowed. The starfish larv8e of even small sizes are far too 

 large to pass through the gillrakers. Numerous schools of men- 

 haden feed in our Bay during the season when the starfish larvae 

 are swimming at the surface, and undoubtedly destroy them by 

 thousands of millions. 



After the stars are set they are no longer in danger of being 

 destroyed by the menhaden, but for several weeks are bright con- 

 spicuous objects upon the seaweed and eel-grass for eels and many 

 small fishes to feed upon. 



