Reptile & Amphibian Forums

From Stebbins (1985) Field Guide

In 1985, based on biochemical data, populations scattered through the Tehachapi Mountains to Fort Tejon, Kern County, were only tentatively assigned to Batrachoseps stebbinsi. However, I have yet to hear more about this situation. In Stebbins new 2003 field guide he does not mention this situation, does this mean that the southern population of this salamander are actually B. stebbinsi? Or is there still a debate whether there could be two species of Tehachapi Slender Salamanders?

William:

That situation has not changed...it is still in limbo. In a forthcoming species account within the book "Status and Conservation of U.S. Amphibians", David Wake and I mention the large genetic variation present within what is currently "stebbinsi." The reality is that the Caliente Canyon segment of the range ("true" stebbinsi) is well isolated from the small populations occurring in the Tehachapi Mountains as far west as Fort Tejon. The genetic distance between those two segments of the range is something like 0.4 or more, indicate of long genetic isolation. Moreover, there are morphological differences evident. We discuss the natural history of both forms separately within the species account in anticipation of future taxonomic partitioning. I hope this helps. Email me if you have further questions.

Regards,

Bob Hansen
rwh13@csufresno.edu

(np)

Large genetic distance between populations of the same species is not uncommon. The genetic distance between some populations of Hyla regilla, for example, as revealed by immunological techniques, can be nearly as large as that between H. regilla and Hyla eximia. Morphological differences between populations of the same species is also not uncommon. Such differences are often recognized at the subspecific level. It would take more than genetic distance and morphological differences to justify the naming of new species. For salamanders, mating behavior is probably the most important means for achieving premating reproductive isolation. If it can be demonstrated that the mating behaviors of the different populations of "stebbinsi" are different, then there would be compelling evidence that speciation has indeed occurred. Otherwise, the genetic and morphological differences are most likely the result of neutral genetic drift due to geographic isolation. As Ernst Mayr pointed out, taxonomists should classify animals on the basis of "genuine evolutionary change" rather than "evolutionary noise useless for the determination of evolutionary divergence."

Thanks for responding. Some slender salamander egg clusters have yet to be found, let alone observing their breeding behavior. It will be interesting to see how many slender salamanders science describes using DNA studies. Speaking of Hyla regilla, do you have any information regarding the distribution of the subspecies in California?

Will

"Thanks for responding. Some slender salamander egg clusters have yet to be found, let alone observing their breeding behavior. It will be interesting to see how many slender salamanders science describes using DNA studies. Speaking of Hyla regilla, do you have any information regarding the distribution of the subspecies in California?

Will"

As far as I know, only one subspecies of Hyla regilla is recognized in California.

As for how many "species" of Batrachoseps will be named, that is a good question. Some molecular systematists treat lineages as species, but a lineage, as Ernst Mayr points out, "applies equally to almost any [geographically] isolated population." If one were to name species on the basis of geographic isolation, then perhaps there is no need to consult DNA data. One can instead use a distributional map and name every isolated population a different species.