In an exciting discovery, a new species of sea slug has been found off the waters of the United Kingdom. Researchers from the Centre for the Environment, Food and Aquaculture Science stumbled upon the previously unknown slug during a routine survey of sea life in southwest England.

Initially, the researchers believed the slug to be the well-known species Pleurobranchaea meckeli, commonly found near Spain and the Mediterranean Sea. However, due to the absence of any previous records of this slug in the U.K., doubts were raised about its true identity.

To unravel the mystery, the specimen was sent to the University of Cádiz in Spain, where experts examined its DNA and physical characteristics. Astonishingly, the researchers discovered that the sea slug had distinct appearances and a reproductive system that differed from other known species. Hence, it was determined to be a brand-new species, named Pleurobranchaea britannica.

Measuring between two and five centimeters in length, the Pleurobranchaea britannica is a small slug with gills on its side. The news release from the center highlighted that this is the first recorded instance of a sea slug from the Pleurobranchaea genus in U.K. waters. Researchers believe that this new species could potentially be found as far south as Spain and Portugal, along the French coast, and up to the southwest of the English Channel.

Sea slugs, despite their small size, play both the role of prey and predator. To defend themselves against predators, some sea slugs have the ability to recycle parts of the prey they consume. For example, if they consume toxic prey, they can secrete the poison into their own skin.

Ross Bullimore, a marine ecologist involved in collecting the specimens, expressed his excitement at the discovery. He commented, "It is exciting to see that routine fisheries surveys can still lead to such discoveries. This was thrilling because no other species from this genus had been documented in U.K. waters, or even this far north." Bullimore further emphasized that there is still much to learn about the species found in U.K. waters.

Hayden Close, a seabed analyst and modeller at the center, echoed Bullimore's sentiments, describing the discovery as "exhilarating" and highlighting the importance of such surveys. Close emphasized that this finding serves as a reminder of the ocean's vast unexplored secrets, even in areas considered well-charted and studied.

The discovery of the Pleurobranchaea britannica not only contributes to the scientific understanding of marine biodiversity but also emphasizes the need for further exploration and research in our own backyard. As researchers continue to uncover new and previously unknown species, it highlights the value of ongoing surveys in uncovering the mysteries of the ocean.