As Salaamu Alaikum,
For as long I can remember I do not eat blue crab because of religious reasons. I have been asked why but I cannot answer. Can you help me with an answer?
Wa Alaikum As Salaam,
The blue crab (or the land crab) is considered to be obnoxious by many scholars and so, they have considered it not permissible to eat. (Al Fiqh Al Islami Wa Adilatihi Vol. 4 page 2799 Maktaba Rasheediya Queta)
Although it feeds on leaves, grasses and fruits, it also feeds on decaying animals flesh, insects and even feces. This therefore, makes its flesh impure and because of its impurity it will not be permissible to eat. (Hayat Al Haiwaan Vol. 2 page. 175 Islami Kutub Lahore).
And Allah Knows best
Mufti Waseem Khan