Dictionary of Ichthyology  

harpoon = a pointed dart with barbs attached to the end of a line several hundred metres in length, the other end of which is attached to a flotation device or shaft. Harpoons are thrown by hand or by a gun mechanism into a fish like swordfish, bluefin tuna. The fish must be seen before being harpooned so can be selected for size and maturity. See also tuna sticker and spear gun.
Swordfisherman, Report U.S. Fish Commission, 1880, from the Freshwater and Marine Image Bank, University of Washington Libraries....more.

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