I have been told that we are not to eat catfish because it does not contain scales and because it is a carnivorous scavenger. Is this true for any madhab, and if so which?
In the three schools of Islamic law other than the Hanafis (namely Shafi’i, Maliki and Hanbali), the general ruling is that the produce of the sea is permitted. Meaning, everything from the sea is lawful to consume with the exception of a sea-dog and sea-pig.
However, according to the Hanafi School, whatever is known to be from the fish family will be permitted, and the rest is unlawful. (Hidaya, 4/71)
Keeping this principle in mind, it is evident that a catfish is without doubt Halal according to the other three schools of fiqh. However, according to the Hanafi school, this depends on whether it is considered a fish or not.
After researching into the catfish, the scholars mention that it is a special type of fish, thus lawful to eat according to the Hanafi School also. (See the Encyclopedia Britannica, for example.)
And Allah knows best
[Mufti] Muhammad ibn Adam
Darul Iftaa
Leicester , UK