I know that fish is Halal for Muslims. Please tell me if shrimp, clams, crab meat and sea foods are also Halal. Let me know specifically which is Halal and which is Haram.

All perfect praise be to Allaah, The Lord of the Worlds.  I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

On the authority of Abu Hurayrah who said, “The Messenger of Allaah said (concerning of the ocean): 'Its water is pure and its dead animals are permissible (to eat).'" [Related by 'The Four Imaams' and narrated by Imaam Maalik, As-Shaafi'i and Ahmad] This Hadeeth states that each and every dead sea animal is lawful and allowable to eat.  On the other hand, the four Imams disagreed concerning the permissibility of eating sea animals that resemble land animals such as people, pigs, dogs, snakes and so on. Imam Abu Haneefah believed that such sea animals are also forbidden since their analogues on land are impermissible to eat.  Imaam Ahmad allowed the eating of all sea animals except frogs, snakes the crocodiles. Imaam Maalik and Imaam As-Shaafi'i believed that all sea animals are lawful to eat with no exception and they based their view on the abovementioned Hadeeth and on the statement of Allaah (what means): {Lawful to you is the pursuit of water-game and its use for food …}[Quran 5:96] By and large, we believe that this last view is the most preponderant one.   

Allaah Knows best.