This isn't quite exact, but 1/4 cup of butter (so a half stick if you're in the US) is 57 grams according to the conversion chart from allrecipes below. So use just a slightly heavy 1/4 cup or 1/2 stick.
Yellowtail, including Yellowtail Jack (Seriol landei), are recognized by a yellow stripe across their body and their yellow tail. Range & Habitat: Yellowtail is caught year round, but more commonly during summer in the Pacific Coast and the Sea of Cortez. They are caught primarily with hook and line, and their average weight is 10 to 20 lbs.
The species can range in weight from 2.8 to 4.4 kg (6.2 to 9.7 lb), with an average mass of 3.65 kg (8.0 lb). As of 2006, the largest concentration of the grey-headed albatross was in fact on South Georgia island, with 46,000 documented pairs. Records change on a daily basis and are not immediately published online.