Got burned by Cichlids of the Americas

lunsforj

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I see your point Rd but I think we may be arguing the same one from different angles. I was under the impression that species once considered to be citrinellum have already been or are in the process of being reclassified as separate species. I may be incorrect on this but, I believe the type specimen for the original species was collected from Lake Nicaragua. Therefore, plasticity should be seen within the lake in various habitats to the extent seen in similar habitats outside the original point of collection. My personal belief is we are dealing with several undescribed species, all being lumped under the name citrinellum.

On a side note, it is very interesting/bold that the author of that paper goes on to suggest jaw structure is not a defining characteristic considering it is one of the primary differentiating properties used to separate species of cichlids in other lake environments (Malawi as an example). Most authors I have read usually begin their analysis of a species with the jaw and teeth structure simply because it's lack of plasticity over long periods of evolutionary time, relatively speaking to other secondary characteristics.
 

neutrino

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Going to branch off a bit here to the extent that genetics enters the picture and most people have an out of date concept of the subject, which is to say most imagine DNA as a static template or blueprint, with adaptations waiting for and dependent on randomly fortuitous dna transcription errors to favorably alter some characteristic of an organism. In fact, what's emerged from the science of recent decades is that DNA works more like software... you can easily research this for yourself.

Without writing a science paper here or a software course, this basically means some species are genetically 'programmed' to respond to certain environmental triggers in predictable ways. A reference below (study of stickleback fish) as to how this can play out in the real world:
https://med.stanford.edu/news/all-n...-on-evolution-from-study-of-sticklebacks.html
The scientists found that the animals — despite their different haunts — repeatedly developed the same traits through changes in similar regions of their genomes. Specifically, the researchers identified 147 regions that varied consistently among freshwater and marine sticklebacks. About 80 percent of the changes involved regulatory regions of the genome that control when, where and how genes are expressed.

“This addresses a classic debate in evolutionary biology,” said professor of developmental biology David Kingsley, PhD, the study’s senior author. “How do new traits evolve in natural populations? Do they arise through mutations in the coding regions of genes, which alter the structure and function of encoded proteins? Or are new traits the result of modifications in the regulatory regions of genes, which control where and when already-established proteins are expressed?”
“The threespine stickleback has evolved like many other animals,” said Kingsley. “But they’ve done it recently enough that they are ideally suited for study. The fact that they’ve evolved the same traits over and over again allowed us to search for those genes that control adaptation to marine or freshwater environments.”
To understand this, it's important to note that certain traits appear repeatedly or can switch back and forth, depending on the environment, and that this switching is not random or accidental, but is controlled by specific genes.

One version of the old model would be that a small number of individuals might already exist with a mutation for an adaptive trait and the new environment favors this trait, which is more successful in the new environment and gradually replaces the standard characteristic in the new population. This might take thousands or millions of years... or perhaps the species dies out, still waiting on such a fortuitous mutation. The new model, which has become evident with the advent of gene mapping, is that species can switch certain traits off or on in response to environmental signals. In very simplistic terms, this might be analogous to your car turning the radiator fan off or on, or its ECU adjusting fuel injection or valve timing according to various sensor inputs.

In a fish species, this could affect color, finnage, scale counts, mouth structure, intestinal length and other characteristics and, depending on the adaptation, might take place within a few generations or even during the lifetime of the individual fish. Another cichlid example would be Malawi cichlids, the current diversity potentially originating as recently as the mid 1800s. Link
 
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RD.

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The original researchers in this area (Barlow et al) studied and collected amphs in both great lakes, so definitely not just one locale. Also, he admits in his earlier papers that even he was confused with some of the early specimens that they collected. If George Barlow didn't know, who are any of us to judge what is the correct defining physical characteristics in this complex, and what isn't? IMO all one can do is exactly what current vendors are doing - which is give the species (as it is currently listed) and supply the collection location. If someone favors one area or collection location over another then they are open to purchase from whatever area floats their boat.
 
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ragin_cajun

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This whole conversation/issue with Midas I think equally applies to Jaguars, too. There are many variations within that species, and just ordering a Jag from a vendor might not get you a fish you're happy with.

Same thing with Umbees I'm finding out, too.

Add to that, the longer you keep fish, the more you notice the differences between them. 3 years ago, I was happy if a fish just grew big. Then, I wanted my fish to have a hump on their head, too. Now, I'm looking at total body shape, size, coloration, all kinds of things I would never have considered 3 years ago.
 

lunsforj

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The original researchers in this area (Barlow et al) studied and collected amphs in both great lakes, so definitely not just one locale. Also, he admits in his earlier papers that even he was confused with some of the early specimens that they collected. If George Barlow didn't know, who are any of us to judge what is the correct defining physical characteristics in this complex, and what isn't? IMO all one can do is exactly what current vendors are doing - which is give the species (as it is currently listed) and supply the collection location. If someone favors one area or collection location over another then they are open to purchase from whatever area floats their boat.
I agree with you to a large extent. I also think that we can also agree that there are two distinct lines of fish here and perhaps. My belief is that it is genetic, having owned and bred WC Nicaraguan citrinellum in past. I guess my main concern as a hobbiest, is lumping two localities into one, sets up a potential hybrid situation in the future, when more information is available.
 

lunsforj

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Just out of curiosity, does anyone know of any genetic mapping that's been done on these fish? I think without it, this whole discussion becomes kind of a circular argument.
 

RD.

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Yes, I agree about breeding the various amphs. I posted the following in my sticky several yrs ago ....

Given the above information I would think that the best approach when breeding any of the above wild caught species is to ensure that both parent fish come from the same body of water, and in some cases the exact same collection location within that body of water. Short of that you might as well consider the offspring of random pairings as Midevils, just like the ones that are found at your LFS.

Having said all that, none of this is Dan's fault, or any other vendors, as long as they are marketing their fish in a responsible manner.
 

lunsforj

Aimara
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Yes, I agree about breeding the various amphs. I posted the following in my sticky several yrs ago ....

Given the above information I would think that the best approach when breeding any of the above wild caught species is to ensure that both parent fish come from the same body of water, and in some cases the exact same collection location within that body of water. Short of that you might as well consider the offspring of random pairings as Midevils, just like the ones that are found at your LFS.

Having said all that, none of this is Dan's fault, or any other vendors, as long as they are marketing their fish in a responsible manner.
Yeah I guess at the heart of all this for me is, if we strip these apparently once thought of as defining characteristics away from the identification process, it removes one more point of reference for authentication. Then essentially the only possible thing you might be left with is a piece of paper that is only about as good as the printing technology the seller has at their disposal.
 

duanes

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I find the plasticity that neutrino cited as an interesting development.
And seems obvious in the way Herichthys minckleyi adapt to the availability of food in Cuatro Cienegas.
At certain times of the year, the molluscan variant (with stronger than normal crushing jaws) becomes very abundant, when the snails become scarce, the predatory variant (with more Parachromis like jaws) takes over, until a sort of equilibrium sets in, and the detritus feeder emerges. And this seems to be cyclic.
 
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