Fig. 1

The round goby mitochondrial genome is one of the largest vertebrate mitochondrial genomes. a Barplot of gobioid mitochondrial genome sizes available on NCBI. Species are ordered according to phylogenetic relatedness as determined in this study. Round goby and sand goby genomes are highlighted in orange. b Histogram of mitochondrial genome sizes of 1708 ray-finned fish for which complete mitochondrial genomes were available. Orange arrowheads indicate the sizes of sand goby and round goby mitochondrial genomes. c Boxplots illustrating the mitochondrial genome size distributions for major vertebrate classes. For 2427 species, mitochondrial genomes as well as class annotations were available from NCBI and IUCN respectively. “Reptiles” includes all members of the reptilia clade (turtles, lizards, snakes, crocodiles etc.) except birds. Orange arrowheads and dotted lines indicate the sizes of sand goby and round goby mitochondrial genomes