wingei or Guppy?

[Fredjikrang]

So, is Endler's Livebearer Poecilia wingei or Poecilia reticulata?

Here is the description of the species Poecilia wingei:
http://dpc.uba.uva.nl/cgi/t/text/text-idx?op4=and;c=ctz;cc=ctz;sid=5f5c897168dc9c2e7ee86ee35198be61;q1=wingei;op2=and;op3=and;rgn=main;view=text;idno=m7401a07

(Please note that it is somewhat technical.)

[Fredjikrang]

And some more articles:
http://www.practicalfishkeeping.co.uk/pfk/pages/item.php?news=889
http://en.wikipedia.org/wiki/Poecilia_wingei
http://www.fishbase.org/Summary/SpeciesSummary.php?id=63223

[Fredjikrang]

So, I have given the first article that I posted a quick look over. Here is the part that I found most interesting:

"The populations of Campoma-like guppies collected in a coastal area of Venezuela, in Cumaná, Laguna de los Patos (Endler, pers. comm.), might very well be an established local population of P. wingei. How guppies were distributed there is unknown; they might be remains of an earlier, wider range of the Campoma guppy, but most likely they are released aquarium specimens originating from the Cariaco- Carúpano region."

[Fredjikrang]

Many thanks to Mikedmathews for information about Dr. Felix Breden, who is doing quite a bit of research about guppies. Dr. Breden has this to say:

"Incipient speciation in the Cumaná guppy  - Theory predicts that sexual selection can promote the evolution of reproductive isolation and speciation. Those cases in which sexual selection has led to speciation should be characterized by significant differentiation in male display traits and correlated female preferences in the absence of post-zygotic isolation, accompanied by little genetic or other morphological differentiation. Previous evidence from our lab indicated that a cluster of populations of the guppy from Cumaná, Venezuela, known in the aquarium trade as Endler’s Livebearer,  differs significantly in female preferences from a nearby guppy population, leading to sexual isolation between these populations. In addition, these populations exhibit significant divergence in male display traits correlated to differences in between-population mating success, little mitochondrial genetic differentiation, and we found no evidence for genetic incompatibility between a Cumaná population and several geographically isolated “standard” populations. These results suggest that divergent sexual selection has contributed to differentiation of the Cumaná guppy, and that this may be the first example of incipient speciation in the guppy.  We are now conducting microsatellite analysis of these populations."

So, at least when he wrote this, he was thinking that Endler's may be an early speciation from guppies. Apparently he presented an opposing position at a recent ALA convention. I will email him and see what he has to say.

[Morgrid]

I was rather shocked that they declared it a seperate species from Poecilia reticulata to tell the truth. Although I would agree it is worthy as keeping as a seperate location I personally don't agree that it is a seperate species. There was genetic research done several years before they split this fish off and it indicated it was a guppy. As I understand it the basis for calling it a seperate species was due to behavior and coloration/pattern. This isn't logical in my opinion, especially when DNA studies are available. If you consider the diversity within other species we have as far as color and behavior it seems strange. Dogs are all the same species, various breeds created by man. Many of them look and behave quite different - same species. Homo sapiens are a diverse species many different colors and behaviors - same species.
On the other hand there are several fish species that have some locations that are very diverse with significant genetic differences (chromosome counts and infertility) yet these fish remain in the same species? Go figure.
I think that the popularity of these fish led to this move into a seperate species.
I don't know why there are not any basic rules for this sort of thing, when it is really fairly important.

[Fredjikrang]

I think what is their basic argument is that the differences in coloration and behavior are enough to allow the two species to exist in the same areas, without combining into an indistinguishable population. Not sure if that is true or not, but it is an interesting idea.

[Morgrid]

The best explaination for these fish I have heard is that they are in the process of speciation. It is hard to say when true speciation would happen, I don't think it has happened, and I don't think it will happen for a long time. Of course this is just my opinion and I am wrong since they have obviously put this one in the books as a species.

[Fredjikrang]

Well, here is the text of the email that I am sending to Dr. Breden. I hope he will respond!

Dr. Breden,

I am the manager of the "fish lab" (Evolutionary Ecology Lab) at Brigham Young University, as well as a moderator on the aquatic hobbyist website Petfish.net. Recently a question has come up that I was wondering if you could help me understand.

Basically the question is, is the hobby's Endler's Livebearer a separate species from the common guppy (Poecilia reticulata)? On your university site, you say:

"Previous evidence from our lab indicated that a cluster of populations of the guppy from Cumaná, Venezuela, known in the aquarium trade as Endler’s Livebearer,  differs significantly in female preferences from a nearby guppy population, leading to sexual isolation between these populations."

And then indicate that you are now conducting microsatellite analysis of the population. Are there any preliminary results from this analysis that you would be willing to share with me?

Also, what do you think of Poeser's description of the species Poecilia wingei? Do you think that their conditions are sufficient for the population they described to be considered a separate species from Poecilia reticulata? And in your opinion, do you think that the fish referred to as Endler's Livebearer is contained within their description?

Finally, I have heard from someone on Petfish that you recently gave a speech at an ALA convention in which you said that Endler's are actually just a population of the common guppy. Is this true, and if it is, is there some way that I could get a transcript or copy of this speech? Or at least of the pertinent portions?

Thank you for any help that you can give me, and all the other hobbyists out there, in understanding the current status of Endler's Livebearer!

[colt-pixy]

Fred, thank you for trying to get more information about this.

[EowynJane]

Oh, I hope he replies too, this is very interesting.

Morgrid - You're not wrong, your own personal opinion can never wrong.  You just don't agree with theirs, or with their actions.