Somehow I missed this article back in March in the Denver Post:
Tiger trout fighting fish of different stripe
By Charlie Meyers
The Denver Post
Article Last Updated: 03/15/2008 10:47:04 PM MDT
A male brook trout, left, and female brown trout form the basic ingredients for making tiger trout. (Colorado Division of Wildlife photo )If a test that began in October on a lake in North Park continues to progress, Colorado anglers soon might have a tiger by the tail.
The trial involves the creation of a hybrid commonly called tiger trout. It is produced by fertilizing the eggs of a female brown trout with the milt of a male brook trout.
The cross fabricates vivid markings that suggest the tiger analogy. It also generates a voracious feeding characteristic that makes it a favorite of anglers and biologists alike.
The Colorado Division of Wildlife launched this project during its take of brown trout spawn at North Delaney Butte Lake, near Walden. This annual activity typically supplies the eggs for all brown trout stocking in the state. This time, the agency added a new wrinkle, or stripe.
The limited number of tiger trout manufactured in this first phase have a well-defined purpose.
Some will be deployed to experimental ponds along the Fryingpan River where DOW researchers are assessing the Hofer hybrid rainbows used to grow trout resistant to whirling disease. The ponds contain an overabundant and competing population of small brook trout. The predatory tigers will be given the opportunity to eat them.
Resistant to whirling disease from the brown trout side of their lineage, these tigers also should help reduce the load of disease-causing spores in the system.
A second task for the tigers will be to gobble suckers and stunted brook trout at certain lakes on Grand Mesa, where they will be available to anglers as well. Presumably, familiarity will breed affection.
"When you make a fish like that and it becomes known, demand goes up," said Kevin Rogers, the DOW research biologist who directed the North Park egg-taking project.
Greg Brunjak, who has produced tiger trout for 23 years at Mount Massive Lakes, a private fishing club near Leadville, can attest to that fact.
"They're highly aggressive. People love them," said Brunjak, who soon was forced to initiate
Chime in With Charlie
Post outdoors editor Charlie Meyers posts entries on this blog devoted to hunting and fishing. Visit it here.
catch-and-release restrictions to keep them in stock.
Brunjak first intended to use tigers to reduce an overpopulation of stunted brook trout. Not only did they gobble up the brookies in short order, they became the club's star angling attraction as well.
Tiger trout appear to max out at 22 inches and about 4 pounds in the rather spare forage conditions at Brunjak's shallow ponds. But the biologist projects bigger and better things in, say, a fertile environment such as Antero or Spinney reservoirs.
"They should do at least as well as rainbow trout. It could be phenomenal," Brunjak said.
As sterile hybrids, tigers have an added advantage in that they don't use energy reserves, or risk injury, during reproduction.
In addition to the value in reducing stunted brook trout or rough fish such as suckers, Rogers predicts a broader utility in replacing WD-susceptible brookies in wild environments.
"We have an opportunity to reduce the ambient spore burden. It can be serve a real purpose and also be a lot of fun," Rogers said.
The only immediate downside to tiger trout is a difficulty inherent in blending separate genera: the brown trout salmo and the brook trout salvelinus. Rogers estimates survival from egg eye-up to fingerling at only about 50 percent. On the other hand, aggressive young tigers prosper in the wild.
Tiger trout sometimes, but rarely, occur in nature when browns and brooks, which share the same autumn reproduction cycle, accidentally mix eggs and milt.
Coloration and marking most resemble brook trout; a mean set of teeth and proclivity for eating other fish stamps them as the progeny of browns.
A so-called "back cross" — female brookie and male brown — yields what commonly is termed a leopard trout, lacking the brook trout worm-like patterns and with more spots. This color pattern is considered less attractive, and the blend seldom is made.
Tigers are just so pretty!