New animal species in the North Sea

Scientists from the Alfred Wegener Institute and the Universities of Oldenburg and Potsdam have succeeded in identifying a new species of amphipod in the North Sea. To characterise the new species, they used genetic information that is otherwise used in other areas of genetics. This approach could one day revolutionise biodiversity research. When people talk about new species in the North Sea, they are often referring to animals or plants introduced by humans. The discovery of a new species of amphipod has now shown that there are also unknown animals hiding on our doorstep. Scientists led by Dr Jan Beermann from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and Dr Michael J. Raupach from the Institute of Biology and Environmental Sciences at the University of Oldenburg, as well as colleagues from the University of Potsdam, have succeeded in discovering and describing a previously overlooked species in the North Sea. This is a rare event, as the North Sea is one of the best-studied marine areas in the world. The new discovery of Epimeria frankei has now been published in the journal Scientific Reports. Originally, AWI ecologist Beermann, together with Michael Raupach from the University of Oldenburg, analysed DNA barcodes of various North Sea crustacean species; small sequence segments that are used in modern biodiversity research. Scientists use these DNA barcodes to create molecular libraries to facilitate species identification. When examining the entries in detail, the scientists began to doubt whether the amphipod species being analysed was actually just one species. "When we took a closer look, we noticed that some animals had more pointed leg plates than others, for example, even if these subtle differences are not easy to recognise," reports Beermann. "The moment you realise that you have discovered a new species is incredibly exciting and fascinating. You don't necessarily expect to come across unknown species in the North Sea. Especially within a genus that is relatively large in the North Sea, measuring up to three centimetres, and which has already attracted the attention of other generations of researchers with its iridescent red colour," says Jan Beermann. The new Epimeria species was christened "Epimeria frankei" after Prof Heinz-Dieter Franke, a renowned ecologist who worked at the AWI on Helgoland for many years and was also Jan Beermann's doctoral supervisor. Comprehensive genomic information With the discovery and the improved information content on the two species, they therefore had to be re-described. "In this context, we wanted to write a species description that was not limited to recording the external appearance, but also included comprehensive genomic information," explains Michael Raupach from the University of Oldenburg. "A few years ago, this kind of recording would have been extremely time-consuming. Today, modern technologies make it possible to analyse them quickly and easily," continues Raupach. In the course of characterising the species, the scientists then used the complete mitochondrial genome, which was decoded using the latest methods. With the support of the genomics team led by Prof Michael Hofreiter from the University of Potsdam, they sequenced the genome using state-of-the-art technologies. "This makes us the first in the world to have analysed the complete genetic material of mitochondria base pair by base pair as part of a species description," say Hofreiter and Raupach, describing their work. Six years from suspicion to confirmation It took a good six years from the initial suspicion to confirmation that this was a different, as yet undiscovered species of amphipod. The species Epimeria cornigera was originally investigated, but the scientists discovered its sister species. It had previously been assumed that Epimeria cornigera could be found from the Mediterranean to Iceland, which would correspond to a large but quite possible distribution area. However, there was still a lack of reliable information about its habits. "We now know that the new species, Epimera frankei, ranges from the Mediterranean to the North Sea, while the old species, Epimeria cornigera, is more likely to be found in the northern North Atlantic. There is only a small area of overlap in the North Sea," explains Jan Beermann. With the description of E. frankei, the number of known Epimeria species in the north-east Atlantic has increased to a total of five. The new discovery makes it clear that marine biodiversity can still be underestimated today and that molecular methods are indispensable in today's biodiversity research. For their publication, the researchers combined extensive analyses from molecular genetics and morphology to create so-called integrative taxonomic methods ("taxonomics"). "The successful validation of the method shows us that taxonomics in biodiversity research can also be of great importance for considerations of marine nature conservation in the future," the authors are convinced. Jan Beermann, Michael V. Westbury, Michael Hofreiter, Leon Hilgers, Fabian Deister, Hermann Neumann, Michael J. Raupach: Cryptic species in a well-known habitat: applying taxonomics to the amphipod genus Epimeria (Crustacea, Peracarida). DOI: 10.1038/s41598-018-25225-x