Iatlantic Logo Hybrid
  • Our Work
    • Work Packages
    • Study areas
    • Expeditions
    • Publications
    • iAtlantic GeoNode
    • iMirabilis2 Expedition
  • Our Team
    • Consortium
    • Steering Committee
    • iAtlantic Fellows
    • Advisory Board
    • Science Council
  • News
  • Events
    • Webinar programme
    • Webinar archive
    • iAtlantic Annual Meetings
    • iAtlantic Workshops
    • iMirabilis2 Expedition
  • Resources
  • Opportunities
  • Contact
Menu
  • Our Work
    • Work Packages
    • Study areas
    • Expeditions
    • Publications
    • iAtlantic GeoNode
    • iMirabilis2 Expedition
  • Our Team
    • Consortium
    • Steering Committee
    • iAtlantic Fellows
    • Advisory Board
    • Science Council
  • News
  • Events
    • Webinar programme
    • Webinar archive
    • iAtlantic Annual Meetings
    • iAtlantic Workshops
    • iMirabilis2 Expedition
  • Resources
  • Opportunities
  • Contact
Login
Search
Close

What’s in a name?

  • 25 November 2021
  • Back
By Stephanie Kaiser
University of Lodz, Poland

Rhachotropis, who? While this question may seem alien to most of us, it is commonplace to others. And to anticipate it: Rhachotropis is a genus of amphipod crustaceans (known as beach hoppers) that is widespread in the deep sea and one of the key players we encounter on this expedition. We, that is, the deep-sea taxonomists here on board, who, roughly speaking, deal with the identification and naming of species. And that can be damned difficult at times. Partly because specimens that we sample from the deep sea are too damaged to reliably name them. Partly because species can simply not be distinguished, since from the outside one species just looks like the other – although their DNA would tell you they are different (something that we call cryptic diversity). And above all, despite all the advances made after 150 years of deep-sea research, sampling the deep ocean floor remains a major challenge. And the forces of nature that we experienced during this trip made this more than clear to us: deep-sea research involves great effort and commitment, is logistically complex and only possible if everyone on board, crew and scientists, pull together.

Rhachotropis, who? Anne-Nina Lörz (University of Hamburg) is definitely the person ask, amphipod expert, but keen to explore deep-sea life of all kinds. (Photo: Viola Siegler)

Hence, naturally, deep-sea taxonomic work is a lengthy one, starting with sample collection, sieving, sorting (i.e. hand-picking individuals from the mud), photographing and initial rough identification, which, including genetic analysis, can already be achieved on board. However, the mammoth task follows in the home laboratory. Here species are further identified and, if recognized as new, named and described. How long this process may take cannot be quantified across the board, but several months to years are not uncommon. To speak figuratively, as a taxonomist you need a lot of stamina, i.e. being more of a long-distance runner than a sprinter. At the same time, however, taxonomy research is more sustainable than any other: species names are still valid after hundreds of years, and specimens from these historical descriptions are available in natural history collections.

Rhachotropis aculeata (Lepechin, 1780) recently sampled from the North Atlantic deep sea (photo: Karlotta Kürzel) and historical illustration of the type specimen.
All taxonomic work starts with separating animals from the mud, and assigning them to major taxonomic groups. Katrin Linse (British Antarctic Survey, Cambridge, UK) and Vivien Hartman (University of Hamburg) carefully handle megafaunal specimens collected by the Agassiz trawl from the deep Labrador Sea. (Photo: Viola Siegler)
Photographing deep-sea specimens as soon as they arrive from the ocean floor is part of the sampling workflow during the IceDIVA 2 expedition; here Nicole Gatzemeier (Senckenberg am Meer, DZMB, Hamburg) is taking the best shot for identifying small-sized deep-sea invertebrates. (Photo: Viola Siegler)

But still, can’t the whole thing be shortened and why is it even important to name species? Living in a time of considerable environmental change, which also extends into the depths of the oceans, we want to know what are consequences for the resident biota? And these can be very different, depending on which species we are dealing with. Coming back to the Rhachotropis example, it makes a huge difference if we find Rhachotropis aculeata, a species common to the North Atlantic, or Rhachotropis boreopacifica usually found in the North Pacific, and thus likely to be an invasive species. Time is of the essence to identify all the different threats to the deep-sea fauna. Therefore, new methods in taxonomy are constantly being developed to accelerate taxonomic work, including modern imaging tools or molecular methods – just to mention metabarcoding or e-DNA, which are also being used here on board. Molecular methods can provide independent evidence of species identification and thus be a valuable addition to traditional morphology-based taxonomy.

According to current estimates, there are thousands upon thousands of species to be discovered in the deep sea, and it is clear that we can only preserve what we know. So, whatever species the next samples will bring to light, we name it!

Taking the home laboratory to the sea: lab facilities on RV Sonne are well suited to allow genetic analysis of specimens directly onboard. Here Jenny Neuhaus, a PhD student from Hamburg is preparing bivalve samples for genetic extraction. (Photo: Viola Siegler)
PrevPreviousTime travellers
NextDeep Blue in Rock: A tour of the ocean’s soundscapeNext

Share this

Subscribe to our newsletter

Get the latest news, events and developments from iAtlantic, straight to your inbox.

iAtlantic_logo
  • Our Work
  • Our Team
  • News
  • Events
  • Resources
  • Contact
  • Our Work
  • Our Team
  • News
  • Events
  • Resources
  • Contact
Facebook-fTwitterInstagram

© 2020 iAtlantic. All rights reserved.

Responsive website design, Development and Hosting by mtc.

Photo by : Andrew Stevenson

EU

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 818123 (iAtlantic). This output reflects only the author’s view and the European Union cannot be held responsible for any use that may be  made of the information contained therein.