FishBase now has species-to-species links to MitoFish, the Mitochondrial Genome Database of Fish, developed by the University of Tokyo and led by Dr. Wataru Iwasaki. These links make it easy for MitoFish users to check the image, distribution and other relevant information currently available for each species. The availability of data from FishBase improves the reliability of species information and fish identification in MitoFish. To date, MitoFish consists of 25,291 species of which 2,151 contain complete mtDNA data. The (deep) links are found in the FishBase species summary pages under Internet Sources.