One of the foods that Blackfish like is grubs this type of grub are found in dead or dying wood , they like them either as grubs or later on as moths , they have several common names so I wont bother trying to name them here.

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it takes a while until the fish will trust you enough for them to be comfortable to show themselves, but with time and food they will become just like puppy dogs, I am not sure this will lead to good breeding habits but I believe when people get to see what a great fish they are more people  will want to protect them , just have a look at the colours , we really need to start calling the something other than blackfish, (southern marbled cod) maybe.

The fish finally sees the grub and its all over in a flash.

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Note the blackfish  poo just in front of the pipe in the second video.