274 Second Annual Report of the 



site. The lamprey, usually in July and August, attacks white- 

 fish, lake herring, bullheads, pikeperch, suckers and other fish for 

 the purpose of sucking out their blood. This seems to be a re- 

 quirement for the proper development of the eggs of the female, 

 and it has caused enormous losses of good fish in New York lakes, 

 and especially in Oneida Lake. The only means available for the 

 prevention of this loss is the capture of the lamprey in weirs and 

 other fishing apparatus during its ascent of streams in which it 

 spawns, and the destruction of the larval lampreys in the mud 

 and sand shoals near the mouths and along the banks of creeks 

 tributary to the lake. The larvae furnish excellent bait for the 

 larger game fish, and many thousands of them are so employed. 

 The Commission might profitably devote some money and effort 

 to the further diminution of this pest which is one of the worst 

 enemies of food fish in Oneida Lake. 



At the Chautauqua Station a shitepoke (a species of heron) 

 destroyed a number of brook trout before it was captured and 

 destroyed. The crow blackbird was also frequently observed 

 capturing trout in the cement ponds outside of the hatchery build- 

 ing, and many of the birds were killed to protect the fish. 



A watersnake, locally known as the black watersnake, was found 

 at the Caledonia Station after it had completely swallowed a ten 

 inch brown trout which was fully two inches deep. The snake 

 was three feet long and only one inch in greatest diameter in its 

 normal condition. 



Inquiries have been made as to the best means of keeping frogs 

 out of fish ponds. To do this for large ponds would involve con- 

 siderable expense, but small springs and rearing ponds can readily 

 be inclosed so as to keep out these animals entirely. A tight board' 

 fence, slightly inclined outward, and with a perfectly smooth 

 surface, raised to a height of 2% or 3 feet, will accomplish the 

 object, or the fence might be made of galvanized iron in which 

 case it should be kept well painted and quite smooth. 



TROUT PARASITES. 



Foreman Annin collected in a Catskill Mountain Lake mrne 

 brook trout which contained worm larvae in the muscle layer? near 



