How cool are fish? Each species is different and has biological differences that control so much about where they live and why. Knowing these facts will help dial in the location and patterns of the fish you seek to catch. Fish identification is just the start. Learning the biological aspects helps us catch and preserve this amazing natural creature. Please bear with me and my poindexter excerpts of “Let’s get to know…”.
Let’s get to know the “Cutbow”
The cutbow trout is a hybrid created from cutthroat and rainbow trout. In the 1880’s rainbow trout were stocked in various waters containing cutthroat trout and shortly after cutbows became prevalent in Colorado waters. The natural version of the cutbow is a hybrid species commonly created when the female cutthroat trout’s eggs are fertilized by the larger male rainbow trout. Hatcheries will most likely create the opposite version as they have more female rainbow trout on hand. One of the primary reasons for covering the hybrid cutbow before discussing the rainbow trout is the fact that a lot of anglers get this hybrid species confused with rainbow trout (and even cutthroat trout in some cases). More details on the biological\ecological instances below but first we will cover the identification.
How to identify the cutbow
The easiest way to identify a cutbow is to look for the most distinguishing marks of both the rainbow and cutthroat trout species; red or orange slash marks under the jaw with silver body. The dotted pattern in some cutbows may be more defined but this characteristic can vary quite a bit. In fact, the physical characteristics can change quite a bit which complicates identification of all three species further.
More about the Cutbow
Spawning: Spawning occurs in springtime when both the rainbow trout and cutthroat trout reproduce. Rainbow trout prefer spawning temps of 40 to 50 degrees. The cutthroat prefers a slightly tighter range of 42 to 48 according to the sources that I have researched. The cutbow is capable of reproducing as well in both natural and hatchery environments. Most anglers think of hybrids as being sterile such as the tiger muskie but natural hybridization occurs in a few fish species within Colorado waters (some trout species as well as bluegill and panfish are a few that come to mind.)
This hybrid species is fairly resistant to whirling disease, an illness that greatly hampers rainbow trout viability in Colorado. Supplemental stockings of the hybrid species have improved the sport fishing in some regions where introduction makes sense. The Colorado Division of Wildlife’s management philosophy has changed in recent decades to try and repair some of the damage done to native cutthroat trout purity. Most biologists agree that the pure DNA and genetic makeup of the native cutthroat trout is at risk as long as rainbow trout (and cutbow trout) exist in native cutthroat trout habitat. Over time the pure strains will degrade and the genetics blurring the lines completely.
The cutbow has a love\hate relationship with most sport anglers in Colorado as it can exhibit amazing hues of greenish yellow with brilliant dot patterns. Size and fight of this hybrid can offer great sport as well. But this bounty of sport comes with a heavy price if we lose the pure species and distinct subspecies of the cutthroat trout. Thankfully we have learned from the past mistakes and keeping the best of both worlds; protection around native cutthroat trout waters and supplementing stocking of other species where appropriate. It is still not a perfect system and a lot of damage has already been done.
* Possible factoid: While researching this subject I came across a possible factoid of a “cutbow vs bowcut” naming convention in regards to the gender order. Most biologists do not differentiate between the two possibilities but one hatchery\biologist stated that there was a difference. This factoid could not be verified through two or more sources so I cannot say this is “bonafide”.
Acknowledgements
http://wildlife.state.co.us/Fishing/ClinicsAndEducation/Hatcheries/
http://www.missouriscenicrivers.com/Rainbow.html
http://wildlife.state.co.us/Fishing/SpeciesID/
http://en.wikipedia.org/wiki/Cutbow
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