No, the yellow color is the mucus secreted from the skin of Pelteobagrus fulvidraco, which is edible.

The yellow mucus of Pelteobagrus fulvidraco has a heavy fishy odor, and once boiled, it rots into a ball, and the stickiness really affects the beauty, so many people use Pelteobagrus fulvidraco to cook like to clean it off.

Put the killed Pelteobagrus fulvidraco in a small pot, sprinkle salt a little pickle, and then put it under running water while rinsing and rubbing, and soon the mucus cleaned up.

Nutritional effects:

Huang Pelteobagrus fulvidraco (also known as yellow bone fish, yellow spicy ding) meat tender and less spiny, sweet taste and flat, can nourish and strengthen the spleen, nourish the yang to wake up the stomach, diuretic and dampness, on the maternal and breast milk through the milk effect.

Yellow Pelteobagrus catfish is ideal for people with high consumption in summer, insufficient qi and blood, colds and flu, and difficulty in appetite as a medicinal meal. Ginger is warm and pungent, and can disperse the sweat, dispel dampness and cold, warm and stop vomiting, and improve appetite.

Reference:

People's Daily Online - Cold Stomach, Boil Pot Pelteobagrus fulvidraco perilla soup

Baidu Encyclopedia - Pelteobagrus fulvidraco salivation