Reptile & Amphibian Forums

Could someone please tell me whether the San Esteban Island rattlesnake is still listed as a molossus ssp or has it gained individual specie status? I was talking to a friend who refered to it as Crotalus estebanesis. Thanks.

Tom

Tom,

Did your friend say where he obtained the info, that this subspecies was elevated to full species? I try my best to keep up with all venomous snake taxonomic updates, however, I might of missed this one if indeed estebanensis was elevated? My sources do "not" reflect that this has taken place, but that doen't mean it isn't so.

I 'll ask WW (Mr. Taxonomy).

Cheers,

Derek K.

NP.

Lee Grismer is the first investigator/author elevating C. (molossus) estabanensis to full species status in several peer-reviewed publications as well as in his recent Amphibians/Reptiles of Baja California (2002). Other insular crotalines previously recognized as subspecies also elevated by Grismer to species status include: C. angelensis, C. lorenzoensis, C. muertensis, C. caliginis. However, Crotalus exsul is no longer regarded by Grismer as a distinct species, but rather incorporated in the C. ruber complex. Crotalus exsul was actually desribed before C. ruber, and although the name has priority, ruber has been retained as name for the species given its popularity.

going away, especially within Crotalinae. That's six each that I wasn't aware of. Cleaning up the C. viridis complex was a blessing, and now more Crotalid ssps have bit the dust.

Thanks for providing the taxonomic update.

Cheers,

Derek K.

according to the C. viridis complex revision: caliginis is considered a synonym of Crotalus helleri?

Derek K.

This could be an issue of names, priority, and the rules/code of the International Commission on Zoological Nomenclature. I previously mentioned the synonymy of C. exsul and C. ruber. The name exsul had priority (as it was first described), but exceptions to the code exist when a name such as ruber is popular and widely used in the popular and scientific literature. While still belonging to the viridis complex/group, but recently elevated to full species status by some investigators, C. caliginis and C. (viridis) helleri are not necessarily synonymous. Grismer addressed the evolutionary distinctiveness of insular species in Baja but didn't wade into the C. viridis split - he retains C. viridis helleri in his recent book. Douglas, Schuett, et al address the caliginis-helleri relationship in their recent treatment of the C. viridis complex but only state that C. v. caliginis is "imbedded" within the C. v. helleri clade - they don't specifically state that they are synonymous.

Another excellent post: However not sure I completely follow.

I was aware and completely understand the C. exsul/ruber

scenario.

The bottom line seems to be: that some authors recognize C. helleri as a full species, and others still consider this serpent a subspecies of C. viridis. Some authors believe that
C. caliginis is the same snake as C. helleri, or C. v. helleri, but others believe that C. caliginis is a valid species, not a subspecies of C. viridis or a synonym of C. helleri or C. v. helleri. Wow, this is getting confusing!

Cheers,

Derek K.

It's ultimately an issue of concensus amongst evolutionary biologists and systemasits. Those that embrace an evolutionary species concept vs. biological speces concept see a different set of relationships, and lump or split organisms as is the case here. It'll all settle out over time.

Sorry ... systematists. Duh!

and the time you took to provide them! I haven't yet taken a look at the other five (5) subspecies that were elevated to full species. I certainly hope there isn't as much controversy surrounding their evelation.

Cheers,

Derek K.

there is already a lot of controversy. Schuett and Douglas et al elevate cerberus, lutosus, concolor, abyssus, oreganus and helleri to full species but Gordon tells me there are several zones of "hybridization" between lutosus, abyssus and concolor for example. He says cerberus does not hybridize/intergrade with any of the other forms. I can vouch for this as I live in northern Az. and spend most of my spare time chasing snakes of the viridis complex around.
Others such as Pook and Wuster, and Ashton and De Quiroz recommend three species: viridis(monotypic), cerberus(monotypic) and oreganus (polytypic with helleri, lutosus, abyssus, and concolor as subs) I would tend to agree with this school of thought personaly. I agree with the separation of oreganus from viridis, and the elevation of cerberus to full species status, but I think the "hybridization" zones mentioned by Gordon actually represent "clinal" or intergradization areas between subspecies. You just have to keep an open mind and remember that mtDNA is not the end-all. From what I have been told, Douglas and Schuett will soon begin research on the viridis complex using nuclear DNA. Who can say what this will reveal? As Bryan stated, it will all be ironed out in the long run.

as to what "might" be, (who knows for sure), the end result pertaining to the somewhat screwed up Viridis complex. I also tend to agree with the Pook/Wuster ect. recommendation, however, isn't that defeating the trend to eliminate subspecies, or will they always be out there? I think for the time being I am going to refer to them as all subspecies of C. viridis, (as before), until things do get more ironed out. It seems one day a species has been elevated, and soon thereafter the species is once again a subspecies. Oh well.

Cheers,

Derek K

I think I will stand back and wait to see how things come out. Until then I guess I'll refer to them as I always have. Rich , the info you gave me awhile back about keeping and breeding blacktails has really paid dividends. Thanks. How's the albino? Have any pics laying around lol

Tom

NP.

the albino is doing good. He was an old adult when caught ten years ago but he is still going strong. I have some pics but have no idea how to post them here. It's one of those things I will have to be shown, lol. I'm not very computer saavy.