Don't Say Fish Require Shchitah

Here is something I found interesting. I have been asked by some why fish do not need any kind of shchitah. The thought is that it is cruel to kill fish the way we do, and why is it permitted? Well I found that the idea of fish needing shchitah is not new, and is addressed in the Midrash Tanchumah Parashas Chukas Sif 6:

Yaakov from Kfar Giboraya taught in Tyre that fish require shchitah. Rabbi Chagai heard this and sent for him. He said to him, "From where did you learn this?" He said to him, "From here," 'G-d said, Let the water teem with teeming living creatures, and fowl, ...'" Just as fowl requires shchitah, so too does fish require shchitah. He said to them, "Prepare him for lashing!" He said, "Is this the law, that a person who says something form the Torah is given lashes?!" He said to him, "You did not teach correctly." He said to him, "How do you know?" He said to him from what is written here, "Can sheep and cattle be slaughtered for them and suffice for them? Or if all the fish in the sea will be gathered for them, would is suffice for them?" These [sheep and cattle] require shchitah, and these [fish] require gathering. He said to him, "Give your lashes for they are fitting and proper that I am lashed by them." (Translation from Metsudah edition)

Therefore, we have a pasuk that tells us that fish do not need shchitah. (However, they require "gathering" - I am not sure what this requirement is. My guess is that they must be dead before eating them.)

This also brings out a very important idea that one should not interpret the Torah on their own, but rather check the interpretation with a Sage.