text: Dehydroretinal (3,4-dehydroretinal) is a derivative metabolite of retinal belonging to the group of vitamin A as a retinaldehyde form, besides the endogenously present 3,4-dehydroretinol and 3,4-dehydroretinoic acid.
  The livers of some freshwater fishes and some fish found in India contain a higher ratio of dehydroretinal to retinal than do other species.