DNA Identification & Vendors

[cchhcc]

And if you can't wait till then you can test for hybridization in your own offspring today....

Funny. You're smart enough to know the difference between races and species though, right? Assuming so, you see the shortfall in your metaphoric image.

Please refrain from posting if you have nothing to contribute to the topic. I moved this discussion to keep from derailing a previous thread. Show me the same respect.

 

[flowerpower]

I know, I know- seriously though, I think we're zeroing in a one example of a much larger problem which is the destruction of ecosystems and the subsequent loss of wildlife. In this case it seems that, for whatever reason, this species is choosing to hybridize with a more successful species i.e. H. cyanoguttatus.

 

[Modest_Man]

H. carpinits actually. Here's how Rusty Wessel distinguished "pure" from hybridized.

Rusty was able to identify the true purebreds by observing them feed. The labridens feed as one stirs up the substrate and changes colors to signal others of its kind for a group feeding frenzy. Herichthys carpintis is a solo feeder. Rusty, with the advantage of scuba gear and a keen eye, was able to identify some nice specimens of the yellow labridens before our long trip to Fort Worth, Texas, where we would share our experiences with friends at the annual ACA (American Cichlid Association) convention.

http://www.cichlid-forum.com/articles/collecting_in_mexico.php

 

[cchhcc]

When was the Media Luna canal finished?

The labridens DNA was not sequenced when the paper was published (2004), it was done in 1997 (by Don Conkel actually! (Roe, K.J., Conkel, D., Lydeard, D.C., 1997. Molecular systematics of Middle American cichlid fishes and the evolution of trophic-types in Cichlasoma (Amphilophus) and C. (Thorichthys). Mol. Phylogenet. Evol. 7, 366–376.)). And even then it was done with museum samples, so who knows when they were collected?

Both labridens types sampled are still grouped with like fish, and not with carpintis (which is what it is has become hybridized with, correct?)

Not sure of the date specifically. I'd bet Juan Miguel and some others could say.

 

[cchhcc]

Interesting post on the ID method. It seems rather crude to me. For instance, what behavior would a hybridized specimen exhibit? Some of this, some of that?

 

[flowerpower]

H. carpinits actually. Here's how Rusty Wessel distinguished "pure" from hybridized.

Quote:
Rusty was able to identify the true purebreds by observing them feed. The labridens feed as one stirs up the substrate and changes colors to signal others of its kind for a group feeding frenzy. Herichthys carpintis is a solo feeder. Rusty, with the advantage of scuba gear and a keen eye, was able to identify some nice specimens of the yellow labridens before our long trip to Fort Worth, Texas, where we would share our experiences with friends at the annual ACA (American Cichlid Association) convention.
http://www.cichlid-forum.com/article..._in_mexico.php

We're talking about DNA analysis and scrutinizing over the purity of Media Luna labridens based on visual observation?... of feeding habits?.... of cichlids? arguably the most diversely adapted family of freshwater fish on earth!? I object. There must be more....

 

[dogofwar]

The carpintis were introduced, as I understand...

Matt

 

[dogofwar]

The carpintis were introduced, as I understand...

Matt

 

[flowerpower]

Anywho, my opinion really doesn't matter

Well, apparently Rusty Wessel's opinion matters a great deal. Not that he's not spot on in his observation but, as a prudent hobbyist with the vast amount resources that he obviously has at his disposal, his observations were surely followed up by DNA analysis. Right?
And at that enough to confirm that these hybridizations are an epidemic within this population of fish and not just a freak occurrence as would be expected periodically anywhere else in nature.
Based solely on Rusty's observation one could hypothesize a number of scenarios. Perhaps, something in the environment was not conducive to group feeding- abundance of food, competition, the nature of the substrate from which they're grazing, predation, etc. Perhaps they learned to mimic the behavior of the feral carpinte or had to adapt to fill a new niche within their changing ecosystem.
Nature has many secrets yet to be shared with those who think they already know.
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[FIN01]

Fact is these fish want to survive. To survive they must reproduce. The stresses of their environment are causing them to make drastic changes. It's unfortunate for the aquarium trade that we are not sure how pure our fish are, but is that really the worst thing that's happening here? These fish are doing the best with what they have, whether it's the 'right' way or not.