Cerataspis monstrosa was the name given to a species of crustacean discovered 180 years ago. It’s only ever been found as larvae in the guts of fish that have eaten it. No adult version was ever identified, leaving scientists understandably curious. Once again, DNA analysis has been the key to unlocking this mystery.
Professor Keith Crandall at George Washington University did a DNA analysis of the creature, dubbed “monster larva” due to its unusual appearance. He found that it’s actually the larval form of what we thought was an entirely different species, Plesiopenaeus armatus. Scientists missed the connection because the adult form, a deep-water shrimp, looks completely different from its younger self. Specimens were also hard to come by because it lives deep in the Atlantic. Professor Crandall put his ability to solve this nearly 200-year-old mystery down to a combination of luck in finding the right specimens and new techniques that have been developed in the last 10 years.