I used to frequently review Ted Coletti's article in TFH regarding Dr Breeden's lecture on the Poeser article. However, I recently stumbled upon a site that now claims a gonopodial difference between Endlers and Wildtype Guppies, can anyone verify this to be accurate?
Thanks

Endler's are Poecilia wingei.

Description of Poecilia (Acanthophacelus) wingei n. sp. from the Paría Peninsula, Venezuela, including notes on AcanthophacelusEigenmann, 1907 and other subgenera of Poecilia Bloch and Schneider, 1801 (Teleostei, Cyprinodontiformes, Poeciliidae)

The problem that I have with description as a species is the part where he writes;

Its closest relative is the common guppy, P. reticulata, sharing identical meristic data, but differing by its enhanced metallic body pigmentation. This brightness in body pigmentation is also noticed in the females of P. wingei. Moreover, in the zone adjacent to the distribution area of the common guppy, P. wingei males exhibit a unique melanophore pattern, viz., a large band in the midsection of its body. The importance of this feature, i.e., the spatial distribution of melanophore patterns, is decisive for its recognition as a valid species.


That is the only difference and makes it a species? I know later on he talks about behavioral differences but that seems pretty week to use for justification that it is its own species. I would like to see the genetic differences between the two “species.”

Melody, that is the Poser article that I really give no credit to it. As I said, Dr Breeden did a wonderful job dissecting and discrediting that article. Gonopodial difference is critical for the taxonomic distinction with livebearers and Poser certainly did not show that with his article, and to my knowledge, that difference has not yet been established. As I mentioned, I stumbled on a site that claimed that difference, but I can not find anything to substantiate its claims.

That will be debated until the Goodeids come home....LOL. I was addressing the question in the title of your thread. The species name of P. wingei is the currently accepted species designation for this fish, to my knowledge, whether we agree with it or not. Maybe I'm missing a technical detail there.

I personally think they should be a subspecies at best, but nobody asked me . I'm more inclined to go with location variant.

I have wild Guppies that look like the classic Endler's Livebearer, but I don't have a lab. That's often the problem with these matters, we can't conclude much with absolute certainty without lab testing.

If they are a distinct species, you can bet our domestic Guppies are hybrids. I find it difficult to believe that they've never been collected before and were just presumed to be P. reticulata.

I debate the whole thing with myself quite often but until anything is proven in a lab, it isn't proven either way, in my opinion.

P.S. He does mention gonopodial differences:

"Comparison. Poecilia wingei differs from most species of Poecilia by the following characters. The gonopodial palp extends clearly beyond the tip of the gonopodium. The gonopodium also lacks a terminal hook at ray 3 ...Females are further distinguished from all other species groups by the unique combination of nine anal fin rays and less than eight dorsal fin rays."

I knew I read it somewhere and there it was, right under my nose. I hate it when that happens.

Too bad when he talks about the tips of the gonopodium being different he is talking about other Poecilia species and not P. reticulata. The first part of the quote from the paper lists "Its closest relative is the common guppy, P. reticulata, sharing identical meristic data."

meristic means: A collection of measurements on a fish like standard length, total length and scale counts etc, which are used to differentiate between populations and races of fish.

Personally I would love for them to be their own species but I don't think it will happen. I agree with your feeling Melody that they are probably a subspecies, a very cool subspecies in my opinion.

He's confusing about that point, as meristic data doesn't necessarily include the gonopodium by definition because not all fish have one. I agree that it should, but he doesn't present it that way. When referring to the female, he specifically says that it's different from ALL others, which would include Reticulata.

I bet you anything that's where the gonopodium information is coming from. In fact, it's presented as part of the argument by Practical Fishkeeping magazine:

"Spot the difference

The most striking difference between Poecilia wingei and P. reticulata is in the structure of the gonopodium.

A structure called the gonopodial palp extends beyond the tip of the gonopodium in P. wingei, but not in reticulata. It also lacks a hook at ray three."

Which is actually the case, I don't know.

Poser did not specify that there was a difference from guppies in his statement about the gonopodium, so the ambiguity caused a great deal of debate. However, the recent description of Poecilia obscura, which is a second species of Guppy found on the island of Trinidad, not only describes the new species, but goes into a detailed examination of the mtDNA of the three 'species', and shows the different gonopodia for all three. While there are differences, I'm not sure they are that significant, especially when one considers that the gonopodium of P. obscura is very different from the other two. As far as the DNA, I've seen a lot of this kind of data from Killies and Cichlids, and again, while I can see the new species on Trinidad, I really don't see anything significant between Guppies and Endler's. However, I am still open, as all the data isn't really in yet.

I have to find the link to the description of the new species, and I'll post it here in a bit when I do.

Edit: It is HERE, read and judge for yourself.

Interesting indeed, thanks for sharing it!