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.
Yellow perch do not accelerate quickly and are relatively poor swimmers. The fastest recorded speed for a school was 54 cm/s (12.08 mph), with individual fish swimming at less than half that speed. Life history. Yellow perch spawn once a year in spring using large schools and shallow areas of a lake or low-current tributary streams. They do not build a redd or nest. Spawning typically takes place at night or in the early morning. Females have the potential to spawn up to eight times in their lifetimes.