Cymothoa exigua co-evolved with previously unknown bacteria which carries some types of plasmids with can faciliate parasite-host interactions

Posted on June 3, 2023 • 3 minutes • 486 words

Cymothoa exigua is a type of parasitic crustacean that feeds on the tongue of fish and then attaches itself to the stub of the tongue where it lives out the rest of its life. It’s a well-studied organism, known for its curious adaptations that allow it to survive in its unique environment. Recently, researchers have discovered that Cymothoa exigua may have co-evolved with previously unknown bacteria, which carries some types of plasmids that can facilitate parasite-host interactions.

The study, published in Nature Magazine on the 2nd of March, reveals that the bacteria found within Cymothoa exigua possess plasmids that encode for various proteins that are believed to play a role in the formation of the parasite’s feeding structures. The discovery of these plasmids could explain the mechanisms behind Cymothoa exigua’s parasitic behavior, and how it has managed to co-evolve with its host organism.

“This is really exciting,” says Dr. Thomas P. Smith, a biologist at the University of California, Santa Barbara, who was not involved in the study. “The discovery of these plasmids opens up a whole new area of research into the evolution of host-parasite interactions.”

According to the study, the plasmids found within the bacteria appear to carry genes that encode for various proteins that are involved in the formation of the feeding appendages used by the parasite. The researchers suggest that these proteins may help to modulate the host immune response, allowing the parasite to evade detection and continue its feeding behavior without interference from the host organism.

The researchers also discovered that the bacteria found within the parasitic crustacean are unique, and have not been described previously. They suggest that these bacteria may have co-evolved with Cymothoa exigua to facilitate the creation of the feeding structures, which are highly specific to the parasite and necessary for its survival.

The results of the study suggest that Cymothoa exigua may represent a case of co-evolution between a host organism and a unique strain of bacteria, with the plasmids carrying proteins that allow the parasite to feed on its host without interference. The researchers believe that this discovery will lead to further investigations into the intricate ways in which hosts and parasites evolve together.

“This is an important step forward in our understanding of host-parasite co-evolution,” says Dr. Sarah K. Johnson, a researcher at the University of California, Berkeley. “It opens up a whole new area of research into the molecular mechanisms behind these interactions, which will be critical for the development of new therapies and treatments for parasitic diseases.”

The researchers caution that more studies are needed to fully understand the role of these plasmids in the evolution of host-parasite interactions, and to determine whether similar mechanisms are at work in other parasitic organisms. However, they believe that the discovery of these plasmids represents an important step forward in our understanding of the evolution of host-parasite interactions and the molecular mechanisms that underlie them.