Salmon spawn baby trout

[Gerritt]

Salmon spawn baby trout

 

LAURAN NEERGAARD

 

Associated Press

 

September 13, 2007 at 3:52 PM EDT

 

Washington — Papa salmon plus mama salmon equals ... baby trout?

 

Japanese researchers put a new spin on surrogate parenting as they engineered one fish species to produce another, in a quest to preserve endangered fish.

 

Idaho scientists begin the next big step next month, trying to produce a type of salmon highly endangered in that state — the sockeye — this time using more plentiful trout as surrogate parents.

 

The new method is “one of the best things that has happened in a long time in bringing something new into conservation biology,” said University of Idaho zoology professor Joseph Cloud, who is leading the U.S. government-funded sockeye project.

 

The Tokyo University inventors dubbed their method “surrogate broodstocking.” They injected newly hatched but sterile Asian masu salmon with sperm-growing cells from rainbow trout — and watched the salmon grow up to produce trout.

 

The striking success, published in Friday's edition of the journal Science, is capturing the attention of conservation specialists, who say new techniques are badly needed. Captive breeding of endangered fish is difficult, and attempts to freeze fish eggs for posterity so far have failed.

 

“They showed nicely that ... they produced the fish they were shooting for,” said John Waldman, a fisheries biologist at Queens College in New York.

 

“Future work should look to expand this approach to other fishes in need of conservation, in particular, the sturgeons and paddlefish,” he added. “We have a lot of species of fish around the world that are really in danger of becoming extinct.”

 

The Japanese researchers' ultimate goal: Boost the rapidly dwindling population of bluefin tuna, a species prized in a country famed for its tuna appetite.

 

“We need to rescue them somehow,” said Goro Yoshizaki, a Tokyo University marine scientist who is leading the research.

 

First, Mr. Yoshizaki's team started with “salmonids,” a family that includes both salmon and trout, and one of concern to biologists because several species are endangered or extinct.

 

Initial attempts to transplant sperm-producing cells into normal masu salmon mostly produced hybrids of the two species that didn't survive.

 

This time, Mr. Yoshizaki engineered salmon to be sterile. He then injected newly hatched salmon with stem cells destined to grow into sperm that he had culled from male rainbow trout.

 

Once they were grown, 10 of 29 male salmon who got the injections produced trout sperm, called milt.

 

Here's the bigger surprise: Injecting the male cells into female salmon sometimes worked, too, prompting five female salmon to ovulate trout eggs. That's a scientific first, Mr. Yoshizaki said.

 

The stem cells were still primitive enough to switch gears from sperm-producers to egg-producers when they wound up inside female organs, explained Idaho's Cloud.

 

Then Mr. Yoshizaki used the salmon-grown trout sperm to fertilize both wild trout eggs and the salmon-grown trout eggs. DNA testing confirmed that all of the dozens of resulting baby fish were pure trout, he reported.

 

Moreover, those new trout grew up able to reproduce.

 

Those first experiments, funded by a Japanese research institute, used still fairly plentiful species to develop the technique. Now comes Idaho's attempt to prove if the method is really useful in trying to produce the endangered sockeye salmon.

 

Last January, Mr. Yoshizaki helped University of Idaho scientists collect and freeze immature sperm tissue from young sockeye salmon being raised at a state-run hatchery. Next month, he'll be back to help Cloud thaw the tissue and implant it into sterile rainbow trout.

 

In Japan, Mr. Yoshizaki is focused on bluefin tuna, noting that standard “marine ranching” techniques are difficult for tuna that can reach man-size.

 

He has begun experiments into how to produce baby tuna from mackerel, which are nearly a thousand times smaller than adult tuna. If it works, “we can save space, cost and labour,” he predicted in an e-mail interview.

[Fisherman]

Well now, maybe not such a bad deal, put our own twist on it, maybe we can hatch some non lying politicians if they are bred by normal people.

[huntervasili]

Wow... thats kinda cool... thanks for sharing

[Golfisher]

Very fascinating, and a bit scary at the same time.

[Gerritt]

Very fascinating, and a bit scary at the same time.

 

 

Humans destroy pretty much everything we touch.... we are screwing with mother nature WAY to much... this is yet another example... Instead of looking at what is causing the problem (already known) and stopping destructive practises, we are devising plans to alter nature as we see fit...Look at our crops, our livestock etc....

 

 

We are willing to pay more for apples not grown with chemicals (Chemicals cost $$$!!!) then you will for apple grown without hormones/pesticides etc.. one would think organic apples would cost less to produce!...

 

I have to say I have changed some of my practises over the last years... I no longer purchase store bought Beef... I buy directly from the farmer I have known since I was a kid.. I know exactly how he treats his animals (they roam his acreage) they are not kept immobile.. and are not fed anti-biotics/hormones to keep them alive.. yes I buy the whole animal.. but myself and family members split it up.. it is the best beef I have ever had and they agree as well... When I say the best I say that from a taste/texture standpoint.. not an ethical one... however I feel it is more ethical to purchase a cow directly from farmer.. know it is treated humanly, know what it is fed and know how it is processed... It is still GOV inspected... my wife and I have issues when it comes to meat products. Besides I am supporting our farmer...Vs, the Packers..(dont mean to rant here)... but we feel comfortable in knowing where our food is coming from... the same holds true for the fish we eat.. I would rather eat a fish from Georgian Bay then a fish kept alive in a tank at Fortinos..

 

Gerritt.