Recent activity has been in the development of quality index method (QIM) schemes suited to individual fish species. Earlier schemes did not take into account the differences among species. To do that, it is necessary to develop one scheme for each species, and the aim when developing QIM for various species is, also, to have the QI increase linearly with storage period of the fish expressed in equivalent days in ice. To develop any new scheme, QIM takes into account the inherent differences among fish species. It is necessary to have some specific knowledge about the fish species, to have on hand two tested and trained sensory panels, a facility to conduct storage experiments under standardized conditions, and to be able to make a statistical validation of the developed QIM scheme.