Those who dispute hybrids,

what is it? Redside dace X what?

I don't know my minners that well. I would say that from the redside dace I have seen, this one just doesn't look right. I will leave it at that.

I have found similar looking fish durring my field research for my masters thesis and they were found in streams where I documaneted redside and s. redbelly dace spawning over the same white sucker nest at the same time. Besides they show intermeadiate charachteristics such as larger mouth than a redbelly but not as large as a redside and a wider gold band than what a redside would normally have and mine had a small amount of red below this widened gold band when captured which looked like a redbelly characteristic. Also the mouth is not as upturned as a redside but rather terminal where a redbelly would be somewhat subterminal. take a look at the pics an say what you think. I added in a pic of my hybrid and a pair of redsides and a s. redbelly.

sorry the hybrid photo is not as good as the other two but I think you can see my points...

sorry the hybrid photo is not as good as the other two but I think you can see my points...

I am unsure as to what fish it is, but if you have more of them, I'd love to take them off your hands. They are very nice looking fish.

Yeah, what he said... I'm dubious of most alleged hybrids myself. Species and their populations typically have large amounts of variability with local environmental conditions stimulating yet more variety.

I don't have any of these fish I keep mainly sunfish, all my pictures were taken in the field creek side and fish released.

Marc Kibbey (OSU Museum of Biological Diversity, assistant curator) Believes this fish to be a regional variation, but nonetheless 100% Redside.

Marc Kibbey (OSU Museum of Biological Diversity, assistant curator) Believes this fish to be a regional variation, but nonetheless 100% Redside.

I don't buy it... Here is why, Look closely at the mouth of your fish, it ends at or near the front of the eye. Now look at the picture of the pair of redside dace I posted, the mouth ends further back under the eye. Variation in coloration is one thing but when you start to see physical differences in body shape that shows that there is something not quite right with the fish. Where was this fish caught by the way? Is this from the kentucky population? If it is then I may be a little more willing to say maybe a regional variant but if this is a mad river or other ohio caught fish I would say it is definately not a pure redside. It may not be a redbelly cross like I beleive the hybrid I posted is maybe a creek chub cross?

I don't buy it... Here is why, Look closely at the mouth of your fish, it ends at or near the front of the eye. Now look at the picture of the pair of redside dace I posted, the mouth ends further back under the eye. Variation in coloration is one thing but when you start to see physical differences in body shape that shows that there is something not quite right with the fish. Where was this fish caught by the way? Is this from the kentucky population? If it is then I may be a little more willing to say maybe a regional variant but if this is a mad river or other ohio caught fish I would say it is definately not a pure redside. It may not be a redbelly cross like I beleive the hybrid I posted is maybe a creek chub cross?

I am also skeptical, but he is still working on it. comparing it against preserved specimens.
Yes it is from the KY population

looks to me like a redside dace with a southern redbelly

I don't buy it...

Yo, Cobber! Would you buy it for a quarter?

I did some digging Skip and yeah I'm with this just being the regional varient of the Redside myself....

Does make you wonder when it will be described as it's own species. It certianly on the outside looks like something that should be split from the typical elongatus. But then again maybe it really does not warrent such a split.

Thought I would bring this back up, as the ID of this fish is still in question. I collected three of these, Todd has one, I have the other two. Phoxinus, Clinostomus, what? Hybrid I say.

The fish were collected in a tributary of the Red river, Kentucky river drainage. Also collected were SRBD, white sucker, stoneroller. There is supposed to be an isolated population of redside dace in the area also, but none were collected.

Thought I would bring this back up, as the ID of this fish is still in question. I collected three of these, Todd has one, I have the other two. Phoxinus, Clinostomus, what? Hybrid I say.

The fish were collected in a tributary of the Red river, Kentucky river drainage. Also collected were SRBD, white sucker, stoneroller. There is supposed to be an isolated population of redside dace in the area also, but none were collected.

Clinostomus of some type. The photo makes it appear to be more dorsoventrally compressed than what I expect from redside dace locally. Rather than hybrid I'd say regional variant like the curator quoted above. Talk is cheap without actually seeing the fish, of course.

I'm fully convinced it's a cross, most likely elongatus x erythrogaster, as both species were present. But I believe that funduloides is also present in the watershed, and it'd be hard to rule that out.

Believe it or not, I can't access Copiea... Can someone who's at a real fish institution grab this?

Morphological Analyses of Four Experimental Intergeneric Cyprinid Hybrid Crosses
Michael R. Ross, Ted M. Cavender
Copeia, Vol. 1981, No. 2 (May 15, 1981), pp. 377-387
doi:10.2307/1444226

There are some other cyprinid hybridization articles I can grab too. Most of the work happened in the 70's and 80's. It would be interesting to see what genetics has to offer in this discussion.

Todd

Here's another one I'd like to see...

Alternative Mating Tactics in Sunfishes (Centrarchidae): A Mechanism for Hybridization?
Martin J. Jennings, David P. Philipp
Copeia, Volume 2002, Issue 4 (December 2002), pp. 1102–1105

Abstract
Lepomis hybridization occurs frequently in natural systems. Previous investigations of sunfish hybridization have focused on courtship behavior of interspecific pairs. We observed spawning in Lepomis nesting colonies where interspecific nest intrusions occurred. Nesting male Lepomis microlophus (redear sunfish) attempted to fertilize eggs in the adjacent nests of spawning Lepomis megalotis (longear sunfish). Male sunfish commonly employ this reproductive tactic in the nests of conspecifics. When colonies contain more than one species, hybridization may occur through interspecific nest intrusion by males on adjacent nests.

I think it's time we stopped using opinions and look at the literature

If you want to get into the hard core dirty genetics stuff too, there's a ton of literature. I just don't want to bore folks with things like this:

Asymmetric hybridization between two species of sunfishes (Lepomis: Centrarchidae)
Konkle, BR; Philipp, DP*
Molecular Ecology [MOL. ECOL.]. Vol. 1, no. 4, pp. 215-222. 1992.

Many of the sunfishes (Centrarchidae) hybridize in natural systems, yet little is known about the interactions among hybridizing individuals in nature. We used allozyme electrophoresis to identify interspecific hybrids between bluegill (Lepomis macrochirus) and pumpkinseed (L. gibbosus) in Lake Opinicon, Ontario, and restriction fragment length polymorphism analysis of mitochondrial DNA (mtDNA) to identify the maternal parentage of those individuals. All 44 individuals collected and identified electrophoretically as F sub(1) hybrids had a pumpkinseed mtDNA haplotype, indicating that hybridization between these species in Lake Opinicon is asymmetrical; F sub(1) hybrids result only from matings between female pumpkinseed and male bluegill.

As my uncle would say to me.... "You say that again, and I'll wash your mouth out with soap!"

Todd

I beleive I have that first sunfish one laying around somewhere, it might have been when I was at heidelberg though and could be lost by now.

If you want to get into the hard core dirty genetics stuff too, there's a ton of literature. I just don't want to bore folks with things like this:

Asymmetric hybridization between two species of sunfishes (Lepomis: Centrarchidae)
Konkle, BR; Philipp, DP*
Molecular Ecology [MOL. ECOL.]. Vol. 1, no. 4, pp. 215-222. 1992.

Many of the sunfishes (Centrarchidae) hybridize in natural systems, yet little is known about the interactions among hybridizing individuals in nature. We used allozyme electrophoresis to identify interspecific hybrids between bluegill (Lepomis macrochirus) and pumpkinseed (L. gibbosus) in Lake Opinicon, Ontario, and restriction fragment length polymorphism analysis of mitochondrial DNA (mtDNA) to identify the maternal parentage of those individuals. All 44 individuals collected and identified electrophoretically as F sub(1) hybrids had a pumpkinseed mtDNA haplotype, indicating that hybridization between these species in Lake Opinicon is asymmetrical; F sub(1) hybrids result only from matings between female pumpkinseed and male bluegill.

As my uncle would say to me.... "You say that again, and I'll wash your mouth out with soap!"

Todd

No doubt, hybridization occurs between different species of Lepomis in particular. But what effect does this have on the species in question? Are these hybrids viable over time in natural systems, do species exist in nature? The above abstract speaks to that by pointing out the asymmetries of inheritance between pumpkinseeds and bluegills. You can hybridize many species of closely related animals, but at best these are curiosities unless reproductive isolating barriers completely collapse and the existing species merge into one.

That's the point the earlier morphological and behavioral studies were making and perhaps I should have just stuck with those, although I felt like I was pulling up antiquated information, which isn't necessarily true. What I would really like to see are studies that managed to produce F2's. That may be the next part of research needed on this type of question.

The answer to each of your questions is "It depends." and is open to a broad range of interpretations. I think Ambystomid salamanders are a great example to play with here, with their polyploidism.

I mean, what is a species of Ambystomid salamander?

A bell curve, basically. One that works out the same, in some cases, over a huge geographical range.

And regardless of wether those characteristics, be they morphological, behavioral, or within strands of RNA are significantly different to Fisher, Bayes or Hurlbert, there's still those messy tails in further derivations, that overlap on these "species".

What forces one set of genetics over another? Abiotic factors such as climate, water availability, biotic factors such as vegetative community or food resources. Selection will favor one group of genes vs another, and statistically, you end up with a "species".

It may stand, that what we see in Lepomis or these pioneering species of Cyprinids is a very similar genetic strategy or phenomena to what happens in these other primitive vertebrates.

However, being limited by longitudinal gradients, such as stream banks, we only catch a glimpse of this, and in disturbed areas where environment is offset or in flux enough to force it in a manner that we can observe. If this longitudinal effect wasn't in place, it's arguable that the reproductive isolating barriers would crash just as is found in these particular salamanders. Ha! Nature isn't so neat and tidy again!

And at worst, it is merely a curiousity, which is why people post pictures of things that just don't look right I just fail to understand why there's so much resistance to identifying "specimen x" as a hybrid maintaing both sets of parent species characteristics instead of a regional variant of a species.

Todd