Fig. 2

Morpho-genomic space of olfaction in ray-finned fishes. A Diversity of olfactory organ morphology. Syngnathus typhle, 283 mm TL, Mola mola, 1290 cm TL, Takifugu rubripes 290 mm TL, Danio rerio, 30 mm TL, Anguilla anguilla, 450 mm TL, Erpetoichthys calabaricus, 268 mm TL, Polypterus senegalus, 112 mm TL. Anterior to left. B Correlation between number of olfactory lamellae and number of olfactory receptor genes; all fishes examined, ranging from microsmatic to macrosomatic, occurred in the blue region of the graph. Most evolutionary transitions in the olfactory organ, indicated by arrows, were simplifications (e.g., S. typhle, M. mola), but expansions (e.g., A. anguilla, E. calabaricus, and P. senegalus) and reacquisition (e.g., T. rubripes) also occurred