2013年6月28日星期五

Sea lampreys turning up the heat

Sea lampreys turning up the heat

Research by a team of Michigan State University scientists found that the males have a secondary sex characteristic that creates heat when they get near a female lamprey, something the females find hard to say no to.

The work of the team focused on a small bump located near the male's anterior dorsal fin. Close examination of this bump determined that it was full of fat cells, cells that are similar to ones found in mammals, animals that need to maintain their own body temperature.

By putting a probe into the bump, the researchers found that the temperature of the bump, also known as rope tissue, increased by 0.3 degrees Celsius when the male approached a female, sometimes even more, depending upon the female.

The role this "bump" played in spawning was not known until now. Scientists had thought it merely as ornamental or playing some other minor role.

"We thought it was just a structure that was used for some kind of mechanical stimulation that they needed to trigger the female to lay eggs," said Weiming Li, a professor of fisheries and wildlife and a team member.

Until now it was believed that males attracted females by releasing pheromones.

By attempting to better understand the reproductive biology of the sea lamprey, the researchers hope to find ways to reduce its numbers or eliminate it from the Great Lakes.

Sea lampreys are a very destructive invasive species. Resembling 18-inch eels, they can live in both salt and fresh water and likely found their way into the Great Lakes via shipping channels. They have no natural predators in the Great Lakes.

Parasitic lampreys attach themselves to other fish, such as salmon, trout and whitefish, and suck out the fish's body fluids. The lamprey's sucking disk and sharp teeth scar the host fish, killing many of them. Under some conditions, only one of seven fish attacked by a sea lamprey will survive.

A sea lamprey can kill 40 or more pounds of fish, and they've caused the extinction of three species of whitefish in the Great Lakes. The U.S. and Canadian governments together spend about $10 million to $15 million per year on lamprey control.

Also contributing to the work were the laboratories of Jongeun Choi, associate professor in the Department of Mechanical Engineering, and Titus Brown, assistant professor in the Departments of Computer Science and Engineering and Microbiology and Molecular Genetics.

This latest research is published in the Journal of Experimental Biology.


Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.

SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc

we are focus on the following fields,and hope we can help you.


AQ12EA100JAJME AQ12EA100JAJBE AQ12EA100GME\500 AQ12EA100GME AQ12EA100GATME\500 AQ12EA100GAJME\500 AQ12EA100GAJME AQ12EA100FAJWE AQ12EA100FAJME\500 AQ12EA100FAJME AQ12EA100FAJBE AQ12EA0R9BAJWE AQ12EA0R9BAJRE AQ12EA0R9BAJME\500 AQ12EA0R9BAJME AQ12EA0R9BAJBE AQ12EA0R8BAJWE AQ12EA0R8BAJME AQ12EA0R8BAJBE AQ12EA0R7BAJWE AQ12EA0R7BAJME AQ12EA0R6DAJWE AQ12EA0R6BAJWE AQ12EA0R6BAJRE AQ12EA0R6BAJME\500 AQ12EA0R6BAJME AQ12EA0R5CAJBE AQ12EA0R5BME AQ12EA0R5BAJWE AQ12EA0R5BAJME AQ12EA0R5BAJBE AQ12EA0R4BAJWE AQ12EA0R4BAJME AQ12EA0R4BAJBE AQ12EA0R3CAJWE AQ12EA0R3BAJWE AQ12EA0R3BAJME AQ12EA150FAJWE AQ12EA150FAJME\500 AQ12EA150FAJME
http://www.suvsystem.com/a/3348.aspx