These fish are scavengers, for years i used to chase Bream spearfishing until i was told a story from a few of the local fishermen.
In the area that i live we have a large amount of cannabis cultivation , we also have a large river that runs through the centre of the shire. Like you could imagine every now and than people raid other peoples crops and people get very upset. Also from time to time people go missing, everyone hears stories over the years of people ending up in the river.
Back to the story, a few of the local commercial fishermen were netting for bream in the river. They ran their nets and pulled a massive haul of bream, most likely spawning?. After the haul they were presented with the repetitive task of gutting the entire catch. As they were gutting one of the boys noticed a hard sausage like object in the gut of one of the fish, to the surprise of the guys it turned out to be a human thumb. These fish are scavengers.
So from that day to today i find it very hard to eat bream without thinking of this true story, better sticking with Kingfish or Mulloway in my opinion. :) I can think of a saying, something like "you are what you eat".