Confidence: I'm as sure as I can be.
Notes: 39cm flounder caught and kept for eating. Remarkably large milt sacks within, extending from the gut cavity backwards within tapering pockets towards the tail. There was a milt sack both above and below the ribs, on the back and the belly of the fish where I was expecting fillets of white fiesh to be. It seems to be a very mature male close to spawning such were the size of the milt sacks. Both milt sacks are present in the 3rd pic. The muscle/flesh on that side of the fish was very much reduced to a strip along the spine in order to accomodate the large gonads which took up almost one full side of the animal.