Behnke revisites topic of Lahontan cutthroat

Bob Behnke weighs in with his thoughts on the Pilot peak Lahontan cutthroat, detailed in the summer 2010 issue of Trout.

 

The story of the Lahontan cutthroat trout of Pilot Peak in the summer issue states that “genetic testing” proved them to be Lahontan cutthroat from Pyramid Lake.  The facts of the matter are: In 1977 my graduate student, Terry Hickman, was working for Don Duff.  Terry went to Pilot Peak to investigate a report of a strange trout.  He collected specimens and sent them to me.  I positively identified them as Lahontan cutthroat based on unique morphological traits such as spotting pattern and number of gill rakers and pyloric caeca (appendages on the intestine) that clearly distinguish the subspecies henshawi from all other subspecies of cutthroat trout.  Hickman and I published a paper in 1979: “Probable discovery of the original Pyramid Lake cutthroat Trout”.  We knew they were Lahontan cutthroat based on morphological characters and that they were introduced because Pilot Peak drains to the Bonneville basin.  A Pyramid Lake origin was based on the evidence that Pyramid Lake was the only known source of hatchery Lahontan cutthroat around the time the introduction was made (about the turn of the century or earlier).  Genetic testing occurred later.  It only verified the obvious; that the Pilot Peak cutthroat is the subspecies henshawi: (The genetics of henshawi is also sharply differentiated from other subspecies of cutthroat and rainbow trout, reflecting about one million years of isolation and independent evolution).  No genetic testing has verified a Pyramid Lake origin.  This assumption is still based on strong circumstantial evidence.

The distinction between “good” subspecies such as henshawi: where genetic and morphological characters can consistently and positively identify the subspecies and dubious or nominal subspecies such as Colorado River cutthroat (pleuriticus) and greenback cutthroat (stomias) is informative for understanding the confusion and controversy regarding unfounded claims of hybridization and greenbacks in Utah.  Dubious subspecies have not been isolated for a sufficient amount of evolutionary time to accumulate diagnostic genetic or morphological traits that can consistently and correctly identify the subspecies.  They are nominal (in name only) subspecies.  A problem is that once dubious subspecies such as pleuriticus and stomias have been named and listed in the literature, it can be difficult to undo invalid recognition.  An analogy can be made between the conviction and imprisonment of an innocent person and a naïve faith that because a species or subspecies has been formally described and named, it must be a “good” or valid subspecies.  In both cases, cognitive dissonance, the aspect of human nature that refuses to admit to an erroneous belief, comes into play.  Just as law enforcement, prosecution, and judicial personnel will resist a fair evaluation of evidence that an innocent victim has been unjustly convicted, geneticists, biologists, and administrators are unlikely to admit mistakes were made in a futile attempt to transform the dubious subspecies pleuriticus and stomias into “good” subspecies by use of what I have called “the illusion of technique”.  How much time and money has been wasted in the erroneous belief that dubious subspecies can be magically transformed into “good” subspecies by modern technology?  The US Fish and Wildlife Service has a long history of fiascos with implementation of the Endangered Species Act when confronted with dubious subspecies such as the Eastern Peregrine Falcon and the Dusky Seaside Sparrow.  Something positive could result from all of this if a critical evaluation is performed explaining how a lack of in-depth understanding of taxonomy, genetics, evolution, and what “Science” is all about can be costly and a serious impediment for implementing the Endangered Species Act.  It’s time for closure..

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