Dictionary of Ichthyology  

jig = 1) one to several bare hooks attached to a weighted line. The hook(s) may have a lead head (lead molded around the hook) and be dressed with, or have a skirt of, rubber, hair, silicone or plastic. Also called bucktail.
Mackerel jigs, National Marine Fisheries Service, Washington. Photograph by Brian W. Coad.

Canadian Museum of Nature