According to shafiz in zabh thy dnt hav to say bismillah according to them to be a muslim is enough so if they leave bismillah purposely then it wil still be regarded halal (sharh mahazab), however wil this be halal?
Answer:
Zabeeha will be halal for Shafi’ee but not hanafi, just like lobsters and crabs etc
Please note that tasmiyah being conditional for zabah is the verdict of imam Abu Hanifa, imam Malik, Sufyan Thawri, and Is’haq ibn rahwayh. It’s also narrated from Hasan Basri, Saeed ibn al Musayyab, Tawoos, Ataa ibn Abi rabaah, imam Ja’far ibn Muhammad as-Sadiq and Rabeea. It is also the more weighty opinion of imam Ahmed ibn hanbal.
The second opinion of imam Ahmed and the mazhab of imam Shafi’ee is that tasmiyah is mustahabb.
(Al mughni p290 vol 13)
So don’t take tasmiyah lightly!! Wassalam