BULLETIN OF THE UNITED STATES FISH COMMISSION 1885.

Note on the Destruction of Mackerel by Dogfish.
By Captain J.W. Collins July 7, 1884

Capt. Joseph Smith, of Gloucester, Mass., tells me that while off Wood Island, Maine, in August, 1880, he observed what he supposed to be at first a moderate-sized school of mackerel at the surface of the water. On closer inspection, however, he found that only a small number were mackerel; probably not exceeding more than half or three-fourths of a barrel, and these were completely surrounded by an immense school of dog-fish. The body of dogfish was formed in such a manner as to inclose the mackerel on all sides and underneath, completely preventing their escape.

Captain Smith had an opportunity of observing the mackerel closely, and says that many of them, he noticed, were bitten by the dogfish, some being deprived of their tails, and others having wounds on their sides. He is of the opinion that every one of the mackerel was ultimately eaten by the dogfish. It is probable, he thinks, that at first a much larger body of mackerel was surrounded. The school of dogfish he estimated to contain at least enough for one hundred barrels, Another school of dogfish surrounding a small body of mackerel was seen on the same day.

WASHINGTON, D. C., July 7, 1384.

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