So dramatic is the metamorphosis of whalefishes that until now scientists thought the larva, adult male and adult female specimens in collections were from three separate families of fishes.

Larva of whalefish <i>Cetomimidae</i>
The larva of a Long-finned Whalefish, Cetostoma regani Image: G. David Johnson
© G. David Johnson

Australian Museum Senior Fellow Dr John Paxton participated in an international scientific collaboration that led to an amazing discovery − whalefishes (family Cetomimidae) are all females, bignose fishes (family Megalomycteridae) are all males and the bizarre tapetails (family Mirapinnidae) are larvae of the one family.

Within this family, the researchers have described a remarkable combination of developmental transformations and dimorphism (difference in appearance between the sexes), unparalleled within vertebrates.

Publication: Johnson, G.D., Paxton, J.R., Sutton, T.T., Satoh, T.P., Sado, T., Nishida, M. & Miya, M. Deep-sea mystery solved: astonishing larval transformations and extreme sexual dimorphism unite three fish families. Biology Letters. 23 April 2009 vol. 5 no. 2 235-239.