Featured Research

from universities, journals, and other organizations

Climate Change Has Surprising Effect On Endangered Naked Carp

Date:
December 20, 2006
Source:
University of Chicago Press Journals
Summary:
A groundbreaking new study reveals an unanticipated way freshwater fish may respond to water diversion and climate change. Endangered naked carp migrate annually between freshwater rivers, where they spawn, and a lake in Western China, where they feed and grow. However, Lake Qinghai is drying up and becoming increasingly more saline -- leading to surprising adjustments to the carps' metabolic rate.

Lake Qinghai's water level has been decreasing 10--12 cm per year during the past fifty years. The naked carp that feed and grow in the increasingly saline water have adapted by drastically changing their physiology.
Credit: Photo courtesy of Chris Wood

Forthcoming in the January/February 2007 issue of Physiological and Biochemical Zoology, a groundbreaking study reveals an unanticipated way freshwater fish may respond to water diversion and climate change. Endangered naked carp migrate annually between freshwater rivers, where they spawn, and a lake in Western China, where they feed and grow. However, Lake Qinghai is drying up and becoming increasingly more saline--leading to surprising adjustments to the carps' metabolic rate.

Naked carp take seven to ten years to reach reproductive size. Although historically abundant, overfishing and destruction of spawning habitat through dam-building caused the species to become endangered during the 1990s. Diversion of water for agriculture from the lake has been compounded by climate change, leading to a decline in water level in the lake of 10--12 cm per year during the past fifty years (see accompanying image).

However, Chris M. Wood (McMaster University) and coauthors found that naked carp respond to the increased salinity of the lake water in a surprising way--by taking a "metabolic holiday." In the first forty-eight hours after transitioning from the freshwater river system to lake water, the carps' oxygen consumption falls --eventually reaching just 60 percent of that in river fish.

Both gill and kidney functions also decline. The sodium/potassium pump (Na+/K+-ATPase), which is a protein critical for cellular function, operated at only 30 percent of its capacity in lake-water fish compared to river-water fish. Ammonia-N secretion by the kidneys declines by a surprising 70 percent, and urine flow decreases drastically to less than 5 percent of its rate in the freshwater river water.

"In other words, the kidney changed from an organ which excreted water at a greater rate than salt in river-water, to one which conserved water relative to salt in lake-water," explain the researchers.

Long-term lake-water-acclimated fish also adjust by actively feeding and have much larger fat stores, the researchers found. In contrast, migrating river fish are anorexic, relying on protein breakdown and higher oxygen consumption to generate energy.

"The MO2 [oxygen consumption] data indicate that the cost of living for the naked carp is 40 percent lower in lake-water than in river-water, and that this difference is almost complete within twelve hours after transfer," write the authors. "The magnitude of this response is remarkable."

But they caution, "If the lake continues to dehydrate, these benefits may change to pathology."

Since 1928, Physiological and Biochemical Zoology has presented current research in environmental, adaptational, and comparative physiology and biochemistry. Original research results represent a variety of areas, including thermoregulation, respiration, circulation, osmotic and ionic regulation, environmental acclimation, evolutionary physiology, and metabolic physiology and biochemistry.

Chris M. Wood, et al. "Przewalski's Naked Carp (Gymnocypris przewalskii): An Endangered Species Taking a Metabolic Holiday in Lake Qinghai, China." Physiological and Biochemical Zoology: 80:1.


Story Source:

The above story is based on materials provided by University of Chicago Press Journals. Note: Materials may be edited for content and length.


Cite This Page:

University of Chicago Press Journals. "Climate Change Has Surprising Effect On Endangered Naked Carp." ScienceDaily. ScienceDaily, 20 December 2006. <www.sciencedaily.com/releases/2006/12/061219170607.htm>.
University of Chicago Press Journals. (2006, December 20). Climate Change Has Surprising Effect On Endangered Naked Carp. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2006/12/061219170607.htm
University of Chicago Press Journals. "Climate Change Has Surprising Effect On Endangered Naked Carp." ScienceDaily. www.sciencedaily.com/releases/2006/12/061219170607.htm (accessed September 30, 2014).

Share This



More Earth & Climate News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Seismic Activity Halts Recovery at Japan Volcano

Seismic Activity Halts Recovery at Japan Volcano

AP (Sep. 30, 2014) Rescuers were forced to suspend plans to recover at least two dozen bodies from near the summit of Mount Ontake in central Japan on Tuesday after increased seismic activity raised concern about the possibility of another eruption. (Sept. 30) Video provided by AP
Powered by NewsLook.com
Raw: Balloon Descends to Bottom of Croatian Cave

Raw: Balloon Descends to Bottom of Croatian Cave

AP (Sep. 29, 2014) An Austrian balloon pilot has succeeded in taking a balloon deep underground, a feat which he believes is a world first. (Sept. 29) Video provided by AP
Powered by NewsLook.com
Bodies Recovered from Japan Volcano Eruption

Bodies Recovered from Japan Volcano Eruption

AP (Sep. 29, 2014) Rescue crews finished recovering the remaining 27 bodies from atop Japan's Mount Ontake Monday. At least 31 people were killed Saturday in the mountain's first fatal volcanic event in modern history. (Sept. 29) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins