Muhtaram Hafiz Saheb, Salamun alaikum!
I consider it an honor to answer your questions.
These animals belong to the shellfish group and they are absolutely Halal on the authority of the Qur'an.
Jews consider these Haram. Most of the ancient "Imams" were Muslims only by name and they declare shellfish Makrooh (detestable) or Haram. We find some "Imams" declaring chicken eggs Haram as well!
5:96 Lawful to you is all water game. This is decent provision for you and for those who are traveling (to Hajj) by sea. Do not pursue land game during Pilgrimage. Be mindful of God to Whom you will be summoned. [Bahr = Sea = River = Any body of water]
16:14 And He is the One Who has made the sea subservient. You eat from it tender fresh meat and take from it gems which you may wear. And on that very sea you see the ships roaming through the waves so that you might seek of His bounty and be appreciative.
7:32 Say, "Who is there to forbid the beauty that God has brought forth for His servants, and the good things of sustenance?” Say, “On the Day of Resurrection, these things will be only for those who chose to believe in Divine laws during the life of this world.” Thus do We detail Our messages for people who make use of what they learn. [17:18-20, 20:117-123]
The Mullahs say, "Well, we are here to make lists of Halal & Haram." :-)