Deep sea research: Mobile amphipods 3,000 metres below the sea NHM Vienna involved in discovery of amphipod species’ global spread
13. October 2023
An international team including researchers of the
Natural History Museum Vienna has become the first to discover specimens of the amphipod predator Rhachotropis abyssalis in
three different oceans, with a distance of up to 20,000 kilometres between them. In each case, the animals live at a depth
of more than three kilometres. The results have been published in the specialised journal “Scientific Reports”.
The abyssal-benthic zone, the deep sea floor below a depth of 3,000 metres, is the earth’s largest habitat and also its least
explored. Recovering invertebrates from such depths is a special challenge for researchers.
Due to their numerous species and large numbers, amphipods are among the key players of the deep sea floor. They are an essential part of the food chain. The females take care of the brood, carrying the eggs and the young in their brood pouches. Thus, contrary to many other marine invertebrates, they do not have free-swimming larvae capable of spreading across large stretches of ocean.
Researchers of the University of Hamburg, the Natural History Museum Vienna and the University of Lodz have now found the amphipod species Rhachotropis abyssalis in the Ross Sea, the Pacific and the North Atlantic, in each case at a depth of several kilometres.
“This is particularly remarkable because there are distances of up to 20,000 kilometres between these regions,” explains Dr. Anne-Nina Lörz, a researcher at the biology department of the Institute of Marine Ecosystem and Fishery Sciences and CEN - Center for Earth System Research and Sustainability at the University of Hamburg. “Yet in all three regions, the animals were extremely similar, both genetically and in terms of their outward appearance.”
This is the first documented case of an invertebrate predator without larval dispersal in the deep sea exhibiting such wide geographical distribution, confirmed by genetic examination at that.
“The species was found in three very distant corners of the globe. We assume that it is also present in regions between these points, where it has simply been overlooked so far,” says Dr. Martin Schwentner of the Natural History Museum Vienna, a co-author of the study.
In 2010, Dr. Anne-Nina Lörz was the first to recover Rhachotropis abyssalis from the Ross Sea in the Antarctic, and to describe the species. The recent additional recoveries were facilitated by expeditions on the research vessel SONNE to the Kuril-Kamchatka Trench and the Labrador Sea, among others.
“Maybe this wide geographical distribution is a rare exception for brooding predators – but possibly, these results are not really an exception at all, but rather a reflection of rare sampling and rare taxonomic investigation of deep sea invertebrates,” says Lörz. “Our results underline that we have much more to learn about deep sea biodiversity and biography in order to understand and thus be able to protect these ecosystems as well.”
Original publication:
Anne-Nina Lörz, Martin Schwentner, Simon Bober, Anna Jażdżewska (2023) Multi-ocean distribution of a brooding predator in the abyssal benthos, Scientific Reports 13, 15867 (2023).
https://doi.org/10.1038/s41598-023-42942-0
Research contact:
Dr. Martin Schwentner
Natural History Museum Vienna
3rd Zoological Department of NHM Vienna
Curator of the Crustacean Collection
https://www.nhm-wien.ac.at/martin_schwentner
Tel. +43 (1) 52177 - 330
martin.schwentner@nhm-wien.ac.at
Press contact:
Mag. Irina Kubadinow
Natural History Museum Vienna
Head of Press & Public Relations, Press Spokesperson
https://www.nhm-wien.ac.at/irina_kubadinow
Tel.: + 43 (1) 521 77 – 410
Irina.kubadinow@nhm-wien.ac.at
Due to their numerous species and large numbers, amphipods are among the key players of the deep sea floor. They are an essential part of the food chain. The females take care of the brood, carrying the eggs and the young in their brood pouches. Thus, contrary to many other marine invertebrates, they do not have free-swimming larvae capable of spreading across large stretches of ocean.
Researchers of the University of Hamburg, the Natural History Museum Vienna and the University of Lodz have now found the amphipod species Rhachotropis abyssalis in the Ross Sea, the Pacific and the North Atlantic, in each case at a depth of several kilometres.
“This is particularly remarkable because there are distances of up to 20,000 kilometres between these regions,” explains Dr. Anne-Nina Lörz, a researcher at the biology department of the Institute of Marine Ecosystem and Fishery Sciences and CEN - Center for Earth System Research and Sustainability at the University of Hamburg. “Yet in all three regions, the animals were extremely similar, both genetically and in terms of their outward appearance.”
This is the first documented case of an invertebrate predator without larval dispersal in the deep sea exhibiting such wide geographical distribution, confirmed by genetic examination at that.
“The species was found in three very distant corners of the globe. We assume that it is also present in regions between these points, where it has simply been overlooked so far,” says Dr. Martin Schwentner of the Natural History Museum Vienna, a co-author of the study.
In 2010, Dr. Anne-Nina Lörz was the first to recover Rhachotropis abyssalis from the Ross Sea in the Antarctic, and to describe the species. The recent additional recoveries were facilitated by expeditions on the research vessel SONNE to the Kuril-Kamchatka Trench and the Labrador Sea, among others.
“Maybe this wide geographical distribution is a rare exception for brooding predators – but possibly, these results are not really an exception at all, but rather a reflection of rare sampling and rare taxonomic investigation of deep sea invertebrates,” says Lörz. “Our results underline that we have much more to learn about deep sea biodiversity and biography in order to understand and thus be able to protect these ecosystems as well.”
Original publication:
Anne-Nina Lörz, Martin Schwentner, Simon Bober, Anna Jażdżewska (2023) Multi-ocean distribution of a brooding predator in the abyssal benthos, Scientific Reports 13, 15867 (2023).
https://doi.org/10.1038/s41598-023-42942-0
Research contact:
Dr. Martin Schwentner
Natural History Museum Vienna
3rd Zoological Department of NHM Vienna
Curator of the Crustacean Collection
https://www.nhm-wien.ac.at/martin_schwentner
Tel. +43 (1) 52177 - 330
martin.schwentner@nhm-wien.ac.at
Press contact:
Mag. Irina Kubadinow
Natural History Museum Vienna
Head of Press & Public Relations, Press Spokesperson
https://www.nhm-wien.ac.at/irina_kubadinow
Tel.: + 43 (1) 521 77 – 410
Irina.kubadinow@nhm-wien.ac.at
© David Bowden / NIWA und Nicole Gatzemeier /DZMB
