What is the ruling on fish blood? I hope for details.

The Hanafī school of thought, which is the soundest view among the Hanbalīs and a perspective among the Shāfiʿīs, holds that fish blood is pure.

In contrast, the Mālikīs and the Shāfiʿīs, according to their soundest view—and it is a saying among the Hanbalīs—maintain that fish blood is impure. This is based on the generality of Allah’s statement: "Forbidden to you are carrion and blood," and the Prophet’s (peace be upon him) saying: "Two types of dead meat and two types of blood have been made lawful for us... As for the two types of blood, they are the liver and the spleen." Thus, no blood other than the liver and spleen was exempted.