Welcome to FIS   Sponsored By
United States
Subscribe to FIS | Register with FIS | Advertise with FIS | Newsletter | About FIS | Contact us
   


Masu salmon specimen, Oncorhynchus masou. (Photo Credit: Apple2000)

How do fish know when to spawn?

Click on the flag for more information about Japan JAPAN
Thursday, July 04, 2013, 05:00 (GMT + 9)

Researchers have unprecedentedly discovered the mechanism through which fish are able to sense the seasons and when it is time to spawn.

Japanese scientists Nagoya University and from Utsunomiya University found that a previously puzzling area of the brain in salmon informs the fish of changes in the length of the day that come with each season.

The results of the study were published this week in the online British scientific journal Nature Communications.

The group of researchers analysed the masu salmon, whose stocks spawn in the autumn, to determine if seasonally breeding fish use a mechanism similar to that of birds and mammals, which have sensors that produce the secretion of hormones that grow testes as the days get longer, The Asahi Shimbun reports.

Appropriate conditions then turn on the production of reproductive hormones that induce fertility and tell the fish it is spawning season.

The researchers divided 20 salmon into two groups and raised them for two months, one group illuminated for 16 hours a day representing summer, and the other for eight hours a day representing winter. After subsequently examining the fishes’ brain tissue, it was found that an area called the saccus vasculosus behaved as a sensor for light.

Scientists then removed the saccus vasculosus from some fish and saw that the testes did not grow as expected in those fish under the artificial conditions and that certain hormones were not secreted.

This means that the saccus vasculosus serves as a sensor for fish to detect which season is approaching and, in the case of autumn, induce breeding, the scientists explained.

These findings regarding how exactly fish perceive seasons and how this affects their brains and hormonal activity may lead to improved breeding programmes and be applicable in other industries, said Takashi Yoshimura, a professor of animal physiology at Nagoya University and a member of the research group.

“It is well established that day length is the dominant seasonal cue for many organisms. But, temperature changes also affect the seasonality in some species. I would like to understand how animals sense changes in temperature to adapt to seasonal changes in environment,” Yoshimura added, according to Asian Scientist.

By Natalia Real
editorial@fis.com
www.fis.com


 Print


Click to know how to advertise in FIS
MORE NEWS
Australia
May 22, 23:50 (GMT + 9):
Mass farmed salmon deaths raises concerns in Tasmania
Oman
May 22, 23:40 (GMT + 9):
Oman closes its ports to pirate fishing
Ecuador
May 22, 23:20 (GMT + 9):
CNA concerns about atypical mortalities in Honduras shrimp farms
Spain
May 22, 23:00 (GMT + 9):
Fishery resources to be assessed in Newfoundland Bank
United States
May 22, 22:20 (GMT + 9):
Genetics provide new hope for endangered freshwater mussels
Norway
May 22, 21:30 (GMT + 9):
Salmon price status at week 21
United States
May 22, 04:00 (GMT + 9):
IN BRIEF - Drought leaves no water to combat salmon-killing parasite
United States
May 22, 04:00 (GMT + 9):
IN BRIEF - Geoduck farming takes off as demand for clams grows in Asia
Australia
May 22, 04:00 (GMT + 9):
IN BRIEF - Australia's commercial fishing industry catches millions of tonnes more than reported: researchers
China
May 22, 04:00 (GMT + 9):
IN BRIEF - Fujian's law enforcement cracks down on illegal fishing
Republic of Ireland
May 22, 04:00 (GMT + 9):
IN BRIEF - Coveney Welcomes Proposed Ban on Fishing for Seabass in Waters Around Ireland
Malaysia
May 22, 04:00 (GMT + 9):
IN BRIEF - Malaysia Shrimp Industry Association demands Luas not to charge water extraction
Norway
May 22, 03:40 (GMT + 9):
IN BRIEF - Cermaq Group AS: Cermaq becomes partner to EAT
United States
May 22, 03:30 (GMT + 9):
Inspection programme raises controversy at Senate
Argentina
May 22, 03:00 (GMT + 9):
Glaciar Pesquera adds new scallop vessel



Lenguaje
FEATURED EVENTS
  
TOP STORIES
Firms benefitting from bluefin tuna quota express uncertainty
Mexico The four tuna companies that can catch 3,000 tonnes of bluefin tuna (Thunnus orientalis) in the Pacific assigned to Mexico are unaware of the reason why the National Aquaculture and Fisheries Committee seeks to set limits on each of them.
Improved biodiesel from fish and cooking oil
Spain Researchers from Granada (Spain) and Campina (Brazil) Universities succeeded in developing a new type of biodiesel that is more resistant to oxidation from mixing fish oil with cooking oil.
Blocked merger with US Foods might pose heavy loss for Sysco
United States The biggest US food distributor, Sysco will have to face about USD 1 billion in costs if a lawsuit to block the merger with US Foods filed early this year has its way.
Horse mackerel fishery negatively affects Oceana's results
South Africa Oceana Group Limited´s results in the six months ended 31 March were affected by increased horse mackerel quota costs and adverse conditions, offsetting the positive performance of the remaining divisions.
 
Maruha Nichiro Corporation
Nichirei Corporation -Headquarter-
Pesquera El Golfo S.A.
Ventisqueros - Productos del Mar Ventisqueros S.A
Wärtsilä Corporation -Wartsila Group Headquarter-
ITOCHU Corporation -Headquarter-
BAADER - Nordischer Maschinenbau Rud. Baader GmbH (Head Office)
Inmarsat plc - Global Headquarters
Marks & Spencer
Tesco PLC (Supermarket) - Headquarters
Pescanova, S.A. - Group Headquarters
Sea Harvest Corporation (PTY) Ltd.
I&J - Irvin & Johnson Limited
Blue Continent Products (Pty) Ltd - (Oceana Group Limited)
Pesquera San Jose S.A.
Nutreco N.V. - Head Office
CNFC China National Fisheries Corporation - Group Headquarters
W. van der Zwan & Zn. B.V.
SMMI - Sunderland Marine Mutual Insurance Co., Ltd. - Headquarters
Icicle Seafoods Inc. -Headquarter-
Starkist Seafood Co. - Headquearters
Trident Seafoods Corp.
American Seafoods Group LLC - Head Office
Marel ehf - Group Headquarters
SalMar ASA - Group Headquarters
Sajo Industries Co., Ltd
Hansung Enterprise Co.,Ltd.
BIM - Irish Sea Fisheries Board (An Bord Iascaigh Mhara)
CEFAS - Centre for Environment, Fisheries & Aquaculture Science
COPEINCA ASA - Corporacion Pesquera Inca S.A.C.
Chun Cheng Fishery Enterprise Pte Ltd.
Food Project (Siam) Co., Ltd.
VASEP - Vietnam Association of Seafood Exporters & Producers
Gomes da Costa
Furuno Electric Co., Ltd. (Headquarters)
NISSUI - Nippon Suisan Kaisha, Ltd. - Group Headquarters
FAO -Food and Agriculture Organization- Fisheries and Aquaculture Department (Headquarter)
Hagoromo Foods Co., Ltd.
Koden Electronics Co., Ltd. (Headquarters)
A.P. Møller - Maersk A/S - Headquarters
BVQI - Bureau Veritas Quality International (Head Office)
UPS - United Parcel Service, Inc. - Headquarters
Hamburg Süd Group - (Headquearters)
Armadora Pereira S.A. - Group Headquarters
NOAA - National Oceanic and Atmospheric Administration (Headquarters)
Omega Protein Corporation -Headquarter-
Marona S.A.
Marine Harvest ASA - Headquarters
Marubeni Europe Plc -UK-
Findus Ltd
Icom Inc. (Headquarter)
WWF Centroamerica
Oceana Group Limited
The David and Lucile Packard Foundation
Ajinomoto Co., Inc. -Headquarter-
Friosur S.A. - Headquarters
Cargill, Incorporated - Global Headquarters
Benihana Inc.
Leardini Pescados Ltda
Mitsubishi Corporation Marine Products Depts. D.Team
CJ Corporation  -Holding Headquarter-
Greenpeace International - The Netherlands
David Suzuki Foundation
Fisheries and Oceans Canada -Communications Branch-
Mitsui & Co.,Ltd - Headquarters
Ocean Trawlers Group - Ocean Trawlers HK Ltd.
Natori Co., Ltd.
Carrefour Supermarket - Headquarters
FedEx Corporation -Headquarter-
AKBM - Aker BioMarine ASA
Seafood Choices Alliance -Headquarter-
Austevoll Seafood ASA
Walmart / Wal-Mart Stores, Inc. (Supermarket) -Headquarter-
New Japan Radio Co.Ltd (JRC) -Head Office-
Gulfstream JSC
INVE Group - Head Office
Marine Stewardship Council - MSC Worldwide Headquarters
Royal Dutch Shell plc (Headquarter)
Genki Sushi Co.,Ltd -Headquarter-
Iceland Pelagic ehf
AXA Assistance Argentina S.A.
Caterpillar Inc. - Headquarters
Tiger Brands Limited
Morpol ASA - Group Headquarters
SeaChoice
National Geographic Society
AmazonFresh, LLC - AmazonFresh

Copyright 1995 - 2015 Fish Info & Services Co.Ltd| All Rights Reserved.   DISCLAIMER