Navigation Links
Climate change has surprising effect on endangered naked carp

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?2 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 a lso 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."

Source:University of Chicago Press Journals

Related biology news :

1. Climate model links higher temperatures to prehistoric extinction
2. Climate change will affect carbon sequestration in oceans, model shows
3. Climate change: The rice genome to the rescue
4. Climate change drives widespread amphibian extinctions
5. Climate experts search for answers in the oceans
6. Climate change creates dramatic decline in red-winged black bird population
7. Climate change could trigger boom and bust population cycles leading to extinction
8. Climate change impacts stream life
9. Climate change was the cause of Neanderthal extinction in the Iberian Peninsula
10. Elusive HIV shape change revealed; Key clue to how virus infects cells
11. Researchers trace evolution to relatively simple genetic changes

Post Your Comments:

(Date:11/17/2015)... , Nov. 17, 2015  Vigilant Solutions announces ... joined its Board of Directors. --> ... after recently retiring from the partnership at TPG Capital, ... companies with over $140 Billion in revenue.  He founded ... across all the TPG companies, from 1997 to 2013.  ...
(Date:11/12/2015)... Nov. 12, 2015  A golden retriever that stayed ... dystrophy (DMD) has provided a new lead for treating ... the Broad Institute of MIT and Harvard and the ... . Cell, pinpoints a protective ... the disease,s effects. The Boston Children,s lab of ...
(Date:11/11/2015)... --  MedNet Solutions , an innovative SaaS-based eClinical technology company ... to announce that it will be a Sponsor of the ... be held November 17-19 in Hamburg , ... iMedNet , MedNet,s easy-to-use, proven and affordable ... been able to deliver time and cost savings of up ...
Breaking Biology News(10 mins):
(Date:12/1/2015)... ... , ... Matthew “Tex” VerMilyea, PhD, HCLD, has joined Texas Fertility Center as ... lab procedures as well as continue his research efforts into the emerging technologies of ... New Zealand to bring home a High Complexity Clinical Laboratory Director named Tex,” says ...
(Date:11/30/2015)... ... 30, 2015 , ... Global Stem Cells Group ... the Santiago Marriott. The Global Stem Cells Group GMP facility is equipped with ... qualified medical researchers and practitioners, experienced in administering stem cell protocols using highly ...
(Date:11/30/2015)... 2015 Partnership includes an MPP ... for the u niversity , s ... treatment s cale - up through ... Africa , where licensees based anywhere in the world will have ... --> Africa , where licensees based anywhere in the world ...
(Date:11/30/2015)... Spherix Incorporated (Nasdaq: SPEX ) an ... and monetization of intellectual property, today provided an ... to create shareholder value. Anthony ... on published reports, the total addressable market of ... Spherix will seek to secure fair and reasonable ...
Breaking Biology Technology: