Help me with this English?

Here is a quotation from "the old man and the sea":"the successful fishmen……had butchered their marlin out and carried them laid …… across two planks".my Chinese translation says "butcher out" means to kill the fish and take the entrails out.That is an interpretation full of imagination.I doubt whether it is right,because "butcher out" literally means to kill them all.I don't ask this question for playing,so if you are not a Native English Speaker,please make sure you really know yes or no,and tell you learn English as a second language