Utah Division of Wildlife Resources
Abatement managers are using the least chub to control mosquito larvae.

The story of the least chub is starting to sound like a "Rocky" movie: Humble native underdog takes on brash, aggressive outsider.

Only in this case, instead of a heavyweight title, the winner gets to eat a lifetime supply of mosquito larvae.

So far, they've only gone round 1. But the underdog already has shown its mettle and is becoming a crowd favorite.

It could be a movie script — if the stars weren't 2.5-inch long fish.

During the 2008 mosquito season, three mosquito abatement districts on the Wasatch Front replaced the mosquitofish normally used to control mosquito larvae in a limited number of ornamental ponds with the least chub, a native Utah fish listed as a conservation species.

They wanted to see if they could tell a difference with how many larvae were eliminated.

And though the least chub didn't come out the clear favorite, mosquito abatement managers want to give it another chance in 2009.

"We found that least chubs weren't quite as effective," said Gary Hatch, manager of the Davis Mosquito Abatement District. "There was about a 5 percent difference in failure to control ponds."

But that could mean 10 or 20 least chubs are required to do the same job five mosquitofish could do in the same pond.

So the 2009 experiment will help managers determine exactly how many least chubs are needed for effective control.

And if more fish are needed, that's just fine with Krissy Wilson, native aquatic program coordinator with the Utah Division of Wildlife Resources. If the least chub is Rocky Balboa, Wilson is Mickey Goldmill, encouraging the champ.

"I have full faith in the least chub," Wilson said. "That's what evolved in this area."

Once homeowners learned they could have a native fish instead of the non-native mosquitofish, they began calling DWR and requesting the least chub, she said.

What managers learned this year was that the least chub's personality is skittish and shy. When abatement district employees went to survey the fish, the least chubs hid in pond vegetation or dived deeper into the water, which made it difficult to count how many least chub survived their placement into ponds.

And when homeowners go out to their ornamental ponds, they like to see their fish.

So more fish per pond may help pond owners enjoy the fish more, Wilson said.

Sammie Dixon, manager of the Salt Lake City Mosquito Abatement District, plans to use a brood stock of least chubs from the DWR to raise the fish during the winter.

"We may run with this one," he said.

That's coming from a person who didn't put a lot of stock in least chubs at the start of the experiment.

But it will take at least another year before managers circulate the least chubs more widely.

The experiment only included 80 ponds each in Davis, Salt Lake City and in the South Salt Lake Valley districts. Each of those districts monitors more than 1,300 ponds. And there may be hundreds more managers don't know about.

But Utah's native fish may just come out on top of its fiercer competition.

Stay tuned for round 2.