I'm from Heilongjiang, and I just bought a kind of fish at the farmer's market. The seller said it was an old fish, but when I came back, my family said it wasn't. I don't know. What is this?

As shown in the picture, mandarin fish

Tang yike? Eleotridae？ Bass pond bream? Pecotz? fish

What is the picture below? Perch, a kind of perch? , commonly known as Shanfeitou, Old Stone Fish and Shagu Perch.

Small fish, often living in swamps, lakes and other still water or slow-flowing rivers with strong adaptability, are carnivorous. The meat is tender and delicious, and the masses love it. Because of its large size and shallow ditches, it is commonly known as "Laotouyu".