Nav: Home

A unique study sheds light on the ecology of the glacial relict amphipod Gammaracanthus lacustris

October 09, 2019

The glacial relict amphipod Gammaracanthus lacustris only occurs in deep and cold waters. A collaborative study by University of Jyvaskyla and University of Eastern Finland produced new information on the life cycle and ecology of this rare amphipod. G. lacustris is adapted to cold water and would probably not survive in rising water temperatures due to climate change. The study has been published in the journal Freshwater Biology in September 2019.

In Finland, G. lacustris only occurs in about 20 lakes. The researchers of Universities of Jyväskylä and Eastern Finland studied the life cycle and trophic position of this amphipod in a unique study, and found that this large amphipod only inhabits the bottom layers of deep lakes with water temperatures less than 8°C. It was mainly found in depths more than 40 meters.

"G. lacustris is abundant only below 40 meters, where water temperature is permanently less than 8°C. The amphipod does not migrate to surface layers to feed even during the night, in contrast to many other crustaceans", says postdoctoral researcher Jouni Salonen from the University of Jyväskylä.

During the many years' of research, samples were also taken during nighttime in Lake Paasivesi, which is a part of the Lake Saimaa complex. The study estimates that there are about 50 million G. lacustris inhabiting the Lake Paasivesi. The species got landlocked in deep, large lakes in southern Finland during the melting process after the latest ice age about 10,000 years ago. Thus, G. lacustris is considered a glacial relict species similar to Saimaa ringed seal, i.e. It adapted to the new lacustrine habitat and diverged from its marine relatives.

Stable isotope analysis proved G. lacustris to be a carnivore

The amphipod is a carnivore that preys on other crustaceans, while itself being the prey for fish that inhabit the bottom layers of lakes. During the study over 600 individual G. lacustris were measured, and the largest ones were over four centimeters long. Based on the length distribution, the largest individuals were four years old.

"The female G. lacustris seem to produce young every year, since all the females longer than 25 mm were gravid, and had an embryo sack. The largest females were carrying over 200 eggs or embryos" tells Jouni Salonen.

The study also included stable isotope and fatty acid analysis of G. lacustris individuals.

"Especially the fatty acid content of gravid females and eggs were high, indicating that G. lacustris invests heavily on producing viable offspring. There also were differences in fatty acid composition between adult amphipods and their eggs. The stable isotope analysis indicated that G. lacustris are carnivores, that feed on zooplankton and other crustaceans", says postdoctoral researcher Minna Hiltunen from University of Jyväskylä.

The values for nitrogen stable isotopes of G. lacustris were at the same level as studied piscivorous fish, such as perch, pike, and pikeperch, which indicates that the trophic position of the amphipod is rather high.

"Due to the high fatty acid content, G. lacustris likely is a valuable prey for many fish, and also seals have been found to eat these amphipods. We also saw that some G. lacustris individuals attacked other crustaceans in the sample jars - even though they were lifted from depths of 60-65 meters only moments ago", says Hiltunen.

The study was conducted before the research vessel Muikku was decommissioned

The increase in air and water temperatures due to climate change threatens this cold-adapted glacial relict amphipod.

"G. lacustris as a relict from the ice age is clearly adapted to cold waters. The species is not likely to survive in warmer waters, and previous studies have found that it cannot migrate to new lakes for example via rivers", say the researchers Jouni Salonen and Minna Hiltunen.

The study was conducted with the unique equipment of research vessel Muikku, which has been decommissioned since then.

"It would not have been possible to do this study and gain this new information on G. lacustris without R/V Muikku. The value of this research on large lakes and their ecosystems will only increase in the future", says professor Jouni Taskinen from the University of Jyväskylä, who originally started the research while working at the University of Eastern Finland.
The study on the ecology of G. lacustris has been published on the journal Freshwater Biology in September 2019:

Further information:

Postdoctoral researcher Jouni Salonen, University of Jyväskylä,, p. +358 40 750 9537

Postdoctoral researcher Minna Hiltunen, University of Jyvaskyla and University of Eastern Finland, p. +358 40 849 0880

Senior Researcher Paula Kankaala, University of Eastern Finland, p. +358 50 431 3496

Professor Jouni Taskinen, University of Jyvaskyla, p. +358 40 355 8094

Communications officer Tanja Heikkinen, the University of Jyvaskyla,, p. +358 50 581 8351

University of Jyväskylä - Jyväskylän yliopisto

Related Climate Change Articles:

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.
Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.
Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.
Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.
A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
Predicting climate change
Thomas Crowther, ETH Zurich identifies long-disappeared forests available for restoration across the world.
More Climate Change News and Climate Change Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at