Trout Lend Sperm To Sterile Salmon

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. US scientists begin the next big step next month, trying to produce a type of salmon highly endangered in the western state of Idaho - 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 US 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...