Short answer
Not in the Hanafi school, which allows only fish from the sea, so crab, lobster, mussels, oysters, clams, squid and octopus are makruh tahrimi (treated as forbidden). The Maliki and Hanbali schools allow them, and the Shafi'i school allows most of them. Followers of those schools may eat them, and Hanafis should not criticise them.
Sea animals other than fish are not eaten. Crab, lobster, crayfish, mussels, oysters, clams, scallops, squid and octopus are all makruh tahrimi.
Other madhhabs
- Maliki
- All sea animals are halal, including crab, lobster and shellfish.
- Shafi'i
- Sea animals are halal, so lobster, squid and mussels are allowed; the main Shafi'i texts forbid crab because it lives both on land and in water.
- Hanbali
- Sea animals are halal, including crab and lobster; only the frog, and some add the crocodile and sea snake, are excluded.
Explanation
This is one of the best-known differences between the schools. The Hanafis read the Quran's ban on khaba'ith (repulsive things) with the hadith that names fish as the lawful dead of the sea, and conclude that only fish is eaten. The other schools read the verse making the game of the sea lawful as covering all sea animals.
For a Hanafi, the common items to watch are:
- crab, lobster, crayfish and langoustine
- mussels, oysters, clams, scallops and cockles
- squid (calamari), octopus and cuttlefish
- oyster sauce and crab or lobster stock in soups and sauces
Imitation crab (surimi) is usually made from white fish, which is halal, but some brands add real crab extract or rice wine, so read the label. Shrimp is a separate case on which Hanafi scholars differ (see shrimp in the Hanafi madhhab).
Each school's position rests on evidence and was held by great imams. A Hanafi eating with Shafi'i or Maliki friends should leave the lobster without making a point of it, and they should not press it on him. Read more about the Hanafi and Shafi'i differences.
The evidence
Quran, Surah Al-A'raaf 7:157
ٱلَّذِينَ يَتَّبِعُونَ ٱلرَّسُولَ ٱلنَّبِىَّ ٱلْأُمِّىَّ ٱلَّذِى يَجِدُونَهُۥ مَكْتُوبًا عِندَهُمْ فِى ٱلتَّوْرَىٰةِ وَٱلْإِنجِيلِ يَأْمُرُهُم بِٱلْمَعْرُوفِ وَيَنْهَىٰهُمْ عَنِ ٱلْمُنكَرِ وَيُحِلُّ لَهُمُ ٱلطَّيِّبَٰتِ وَيُحَرِّمُ عَلَيْهِمُ ٱلْخَبَٰٓئِثَ وَيَضَعُ عَنْهُمْ إِصْرَهُمْ وَٱلْأَغْلَٰلَ ٱلَّتِى كَانَتْ عَلَيْهِمْ ۚ فَٱلَّذِينَ ءَامَنُوا۟ بِهِۦ وَعَزَّرُوهُ وَنَصَرُوهُ وَٱتَّبَعُوا۟ ٱلنُّورَ ٱلَّذِىٓ أُنزِلَ مَعَهُۥٓ ۙ أُو۟لَٰٓئِكَ هُمُ ٱلْمُفْلِحُونَ ﴿١٥٧﴾
Those who follow the Messenger, the unlettered prophet, whom they find written in what they have of the Torah and the Gospel, who enjoins upon them what is right and forbids them what is wrong and makes lawful for them the good things and prohibits for them the evil and relieves them of their burden and the shackles which were upon them. So they who have believed in him, honored him, supported him and followed the light which was sent down with him - it is those who will be the successful.
The Hanafi basis for leaving sea animals other than fish.
Quran, Surah Al-Maaida 5:96
أُحِلَّ لَكُمْ صَيْدُ ٱلْبَحْرِ وَطَعَامُهُۥ مَتَٰعًۭا لَّكُمْ وَلِلسَّيَّارَةِ ۖ وَحُرِّمَ عَلَيْكُمْ صَيْدُ ٱلْبَرِّ مَا دُمْتُمْ حُرُمًۭا ۗ وَٱتَّقُوا۟ ٱللَّهَ ٱلَّذِىٓ إِلَيْهِ تُحْشَرُونَ ﴿٩٦﴾
Lawful to you is game from the sea and its food as provision for you and the travelers, but forbidden to you is game from the land as long as you are in the state of ihram. And fear Allah to whom you will be gathered.
The verse the other schools read as allowing all sea animals.
Sunan Abi Dawud 83
Graded sahih... هو الطهور ماؤه الحل ميتته ...
"Its water is pure and its dead animals are lawful."
The other schools take this as general for all sea animals; the Hanafis apply it to fish.
Where the ruling is recorded
- al-Hidaya, Kitab al-Dhaba'ih, on sea animals. Sea animals other than fish are disliked.
- Minhaj al-Talibin, Kitab al-At'ima. The Shafi'i ruling on sea animals and the exclusion of animals living on land and in water.
- al-Mughni (Ibn Qudama), Kitab al-Sayd wa al-Dhaba'ih. The Hanbali view that sea animals are lawful.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.