322 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [34] 
the surface in water of temperature ranging from 55° to 70°, sinking 
when cool winds blow? The case seemed clear enough until this per- 
plexing discovery was made, that Sword-fish are taken on bottom trawl- 
lines. In other respects their habits agree closely with those of the 
mackerel tribe, all the members of which seem sensitive to slight changes 
in temperature, and which, as a rule, prefer temperature in the neigh- 
borhood of 50° or more. 
There is one theory by which this difficulty may be avoided. We 
may suppose that the Sword-fish take the hooks on their way down to 
the bottom; that in their struggles they get entangled in the line and 
nooks, and when exhausted sink to the bottom. This is not improbable. 
A conversation with some fishermen who have caught them in this way 
develops the fact that the fish are usually much tangled in the line, and 
are nearly lifeless when they are brought to the surface. A confirmation 
is found in the observations of Captain Baker, of the schooner “ Peter D. 
Smith”, of Gloucester, who tells me that they often are taken on the hand- 
lines of the codfishermen on George’s Banks. His observations lead 
him to believe that they only take the hook when the tide is running 
very swiftly and the lines are trailing out in the tide-way at a consider- 
able distance from the bottom, and that the Sword-fish strike for the 
bottom as soon as they are hooked. This theory is not improbable, as I 
have already remarked, but it is not at present very strongly advocated. 
I want more facts before making up my own mind. At present the 
relation of the movements of the Sword-fish to temperature must be left 
without being understood. 
The appearance of the fish at the surface depends apparently upon 
temperature. They are seen only upon quiet summer days, in the morn- 
ing before ten or eleven o’clock and in the afternoon about four o’clock. 
Old fishermen say that they rise when the mackerel rise, and that when 
the mackerel go down they go down also. 
23.—PROBABLE WINTER HABITAT OF THE SWORD-FISH. 
Regarding the winter abode of the Sword-fish conjecture is useless. I 
have already discussed this question at length with reference to the 
menhaden and mackerel. With the Sword-fish the conditions are very 
different. The former are known to spawn in our waters, and the schools 
of young ones follow the old ones in toward the shores. The latter do 
not Spawn in our waters. We cannot well believe that they hibernate, 
nor is the hypothesis of a sojourn in the middle strata of mid-ocean 
exactly tenable. Perhaps they migrate to some distant region, where 
they spawn. But then the spawning time of this species in the Medi- 
terranean, as is related in a subsequent paragraph, appears to occur in 
the summer months, at the very time when our Sword-fishes are thronging 
our own waters, apparently with no care for the perpetuation of their 
species, 
