This deep sea creature, the whalefish (Cetomimidae), has a whale-like body, a gaping mouth, no fins or scales and a deep lateral line, which detects vibrations in the water. The first specimens were discovered by two Smithsonian scientists in fish collections at the National Museum of Natural History more than a century ago. In the 1980s, a different scientist realized that they only had female adults in the museum collections. Where were all the males? It would take another 20 years to find out. Find out how this fish was part of an international scientific mystery.