The origin of Cerataspis monstrosa has been a mystery as deep as the ocean waters it hails from for more than 180 years. For nearly two centuries, researchers have tried to track down the larva that has shown up in the guts of other fish over time but found no adult counterpart.
George Washington University Biology Professor Keith Crandall cracked the code to the elusive crustacean's DNA this summer. His findings were recently published in the journal Ecology and Evolution, and his research was funded by the National Science Foundation and the Gulf of Mexico Research Initiative. In it, Dr. Crandall, the senior author of the paper, explains how "monster larva" and the deep-water aristeid shrimp known as Plesiopenaeus armatus are one in the same: larvae and adult forms of the same species. Attempts to find the adult incarnation of the larva weren't without significant effort over the span of time.
The crustacean's ability to morph into a shrimp bearing no resemblance to its juvenile form was a challenge as externally, the two couldn't be more different. C. monstrosa, has heavy armor, a thick body and exceptional horn ornamentation. Described as "monstrous and misshapen animal," it is the preferred meal for its predators such as skipjack, yellowfin and blackfin tuna and dolphin.
The Plesiopenaeus, resembles a lobster or crab with its red, enclosed exterior and is elusive. It calls the deep sea waters such as the Atlantic Ocean home but finding the specimen to make a match has proven to be difficult for zoologists. Dr. Crandall said it was not until the late 19th century that researchers started to suspect a link between the Cerataspis and some of the deep sea shrimp.