Question Summary:
what is the hanafi ruling with regards to the consumption of Prawns, shrimps, crabs, shark, oysters, octopus, scampi,whale?

Question Detail:

What is the Hanafi ruling with regards to the consumption of the following and what is your view to eating in a restaurant that sells these products?
PrawnsShrimpsCrabsSharkOystersOctopusScampiWhale.
 
Jazakallah

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
1)     There are differences of opinion among competent and reliable Ulama regarding the permissibility of eating prawns and shrimps. Some Ulama hold the view that eating shrimps and prawns is permissible while others say they are not permissible.
The differences are due to the categorization of prawns and shrimps. Those who hold the view of the permissibility of eating prawns and shrimps believe that they are fish. Others believes that they are not fish.
 In view of the differences of opinion; there is a leeway for eating prawns and shrimps. However, it is taqwa to abstain from eating them [1]
2) Crabs and scampi are crustaceans. It is not permissible to eat crustaceans. [2]
3) Oysters and octopus are molluscs. It is not permissible to eat molluscs. [3]
4) Whales are mammals. It is not permissible to consume whale meat. [4]
5) Sharks are fish. It is permissible to consume shark meat. [5]
Note: If there is need to eat at a restaurant that serve the above, then eat only fish.
 
 
And Allah Ta’āla Knows Best
Ismail Dawoodjee
Student Darul Iftaa
Zambia
Checked and Approved by,
Mufti Ebrahim Desai.
www.daruliftaa.net 
.wikipedia.org/wiki/Prawn[1]
لايوكل من حيوان الماء الا السمك(قدورى ص277 سعيد)
احسن الفتاوى ج7 ص391 سعيد
wikipedia.org/wiki/Crab[2]
wikipedia.org/wiki/Scampi
و نهى عن بيع السرطان و الصيد المذكور فيما تلا(الهدية ص442 ج4 رحمانية)
.wikipedia.org/wiki/Octopus[3]
.wikipedia.org/wiki/Oyster
wikipedia.org/wiki/Whale[4]
wikipedia.org/wiki/Shark[5]