The 5th bar in a heckel? strong eye bar?

[brewmaster15]

Hi all,
I know theres much disagreement on how many wild species there are...some feel heckels are one, all else is another... some say 3 species... some say one species......still others say greens are a species...and all else is another species...

Not going to touch that at this time much... I have my own ideas on that based in my biology background, but having not even been to where these fish live...I'll reserve too much comment and speculation at this time...

What I am interested in here is your views on a very distinctive feature... the heckel's prominent 5th bar. Do you think that any discus bearing that bar is a heckel or the result of a heckel cross (either to a domestic or a wild)?

How about the eye bar...yes even our domestics bear it depending on the strain... as do many wild... but these eye bars are not as bold as what one might see in a heckel...so if you see this eye bar with that 5th Bar ...again....do you see heckel?

or does this very distinct feature not matter, all other things considered?

thoughts welcome!

-al

[Apistomaster]

My thoughts are that the bars are all examples of disruptive coloration(camoflage) that helps discus blend in with underwater brush and branches regardless of which wild variety we are considering.

Form follows function. The discus form as well as that of Pterophyllum allows them to easily navigate thickets and both genera share the traits of vertical bands in roughly similar distribution across their bodies.

In fish evolution in general, the eye stripe is a very common feature. Most predators strike head first. If a band through the eye causes the slightest indecision on the predator's part the chances of the prey's survival is enhanced.

These features did not come about in nature to please aquarists but to assure survival of the species.

Larry W.

[yogi]

I'm having trouble getting a good picture of this fish with it's fins erect. This is an f1 of a male heckel cross wild brown female that had a partial heckel bar.

[Ed13]

My thoughts are that the bars are all examples of disruptive coloration(camoflage) that helps discus blend in with underwater brush and branches regardless of which wild variety we are considering.

Form follows function. The discus form as well as that of Pterophyllum allows them to easily navigate thickets and both genera share the traits of vertical bands in roughly similar distribution across their bodies.

In fish evolution in general, the eye stripe is a very common feature. Most predators strike head first. If a band through the eye causes the slightest indecision on the predator's part the chances of the prey's survival is enhanced.

These features did not come about in nature to please aquarists but to assure survival of the species.

Larry W.

Adding to this, Keep in mind the pronounce dark bars are the first, fifth and last
If a predator can't tell which way the prey is facing it may hesitate, if it attacks there is a chance that it will attack the wrong side allowing the fish to escape (many wild discus show scars near the middle or end, then again if a piraña attacks the head.... ). Also discus are shoaler or schoolers the bars will help them blend with one another so there is safety in numbers. And don't forget that angels and discus swim among roots and submerged trees so along with the tea colored water the bars might help the blend with trees in the background.

As far as the bar making it a heckel, without DNA to compare as a hobbyist, the bar and to some degree the location makes me call any discus with a strong 5th bar a Heckel, Heckel cross or variation of. Kinda like tangs( not the best example though, because they do belong in the same family) are called Surgeon fish for the blades they posses in the tail without care of location

[brewmaster15]

Hi Larry,

My thoughts are that the bars are all examples of disruptive coloration(camoflage) that helps discus blend in with underwater brush and branches regardless of which wild variety we are considering.

I agree with you 100% on some of the stress bars general purpose in the wild...

What are your thoughts on how this very prominent eye bar and more importantly , 5th bar, play in the identification of fish that are heckels or heckel crosses?



-al

[Apistomaster]

I trust the 5th bar as a Heckel characteristic on Heckels.
When it occurs on other discus, especially wild browns/blues I think it is a different matter. The 5TH bar can appear postive(dark) or in the negative(light), on fish not related to Heckels. If it appears in a natural or captive Hybrid it means nothing to me as that fish is not likely to be contributing to the gene pool.
I do not attach a lot of significance to the variations in color and patterns of non-Heckel discus because I think they are a very variable marked species and any given trait can be selectively bred for. In nature I think it is a random trait shown on a small percentage of the Blue/Browns.

The 5TH bar appearing similar to a Heckel's does not seem to occur among the greens to my knowledge. I can only go by what I have seen. Doesn't prove that there isn't a green out there with the prominent 5th bar.

As to function of the Heckel's Fifth bar I can only speculate that it has something to do with the social functions within their groups. Dominance, fright, or well being.
Larry

[dandestroy]

I believe that if that bar do show in a cross strongly enough to be compared to a wild bar, it is because the gene involved in making that bar is clearly a dominant one for that particular cross. Since it is autosomal and will be passed to next generation, I believe it it safe to consider it a heckel. But to be fair someone should state that it is a cross of course and not a pure breed.

Its like dogs, you could see a golden retriever but the breeder should tell you if there was any labs cross at some point... still it is a golden when you look at it, and if you go down to the gene level it should be golden and not pitbull.

[brewmaster15]

Larry,
If all heckels carry a pronounced 5th bar, and in other color forms we see it rarely ( in relation to the total numbers of wilds without it) does it not seem that the 5th bar indicates relationship to the heckel line?

In nature I think it is a random trait shown on a small percentage of the Blue/Browns.

How can it be specific to heckels and random to other color forms of discus.. a more likely scenario biologically is the non-heckels with that trait, have it because their recent ancestry has heckel in it. I say this as in nature, "random" mutations are usually either fatal and not passed on in a gene pool or they are absorbed and quickly bred out of the gene pool....unless others in the pool have that trait... at least thats how it works with everything non-discus.

Even pure species closely related can interbred where their ranges overlap even temporarily..happens all the time and integrates are very common.In the northeast...it happens with Black rat snakes and corn snakes.. I have seen these in person in the wild.

I guess my question next is ... If all heckels have the heckel's 5th bar, but not all wilds with the 5th bar are heckels or heckel derrived...how then do you tell a heckel from a non heckel?

-al

[brewmaster15]

I should clarify this...

say this as in nature, "random" mutations are usually either fatal and not passed on in a gene pool or they are absorbed and quickly bred out of the gene pool....unless others in the pool have that trait... at least thats how it works with everything non-discus.

Random mutations can become established traits when they aid in the survival of the species, by giving the individual a better edge in survival and thus passing them on.

hth,
al

[Apistomaster]

Al,
My personal theory about the cenral bars goes along these lines:
1. S. discus is ancestral to all subsequent forms/species.
2. Their are multiple genes controlling the number and intensity of the bars bars. Those controlling an emphasized 5th bar are recessives carried forward from the Heckel or an even earlier form. This particular combination is only rarely expressed in non-Heckels by chance. Local populations may have a greater frequency of the correct genotype so that some fish express this phenotype more frequently than others. Example: The green discus far upstream to the West are probably the least ancient species geographically and reproductively isolated in a different environment and have developed along a different path in response to their relative isolation.
3. Rolling the dice enough times over a million years and I believe some gene flow has rarely occured successfully from Heckels to Blue/browns. This reinforces the potential of the 5th bar being seen more often in those fish.
But I still think it is recessive and a rare occurence in the wild population.
4. In the case of F1 HeckelXBlue/Brown the Heckel 5th bar is dominant coming from the Heckels that always have it. I believe these hybrids are not very important due to their reduced viability.
In the case of#3 time has allowed for the possible success at least occassionally of some hybridization.
I do not think this process is occurring in nature much as the species continue down the road of differentiation becoming less genetically compatible. Very early on I think things were less clear cut. (As if my ramblings are.)
Don't know if I made any sense. Now what was your question?
Larry

[Rod]

Well i have given my thoughts on this before and i have seen nothing to sway my opinion. All discus races that show the bar to some degree are either heckels or derived from heckels and vary a lot because of natural evolution. In some areas it is good to look like a heckel(rio negro tribe) with all those wide bands and in other areas it is an advantage not to have them, and in some areas it wouldn't make a whole lot of difference. This is nature at its best, choosing those specimens with best fit into a niche. Of course this is jmo.

[brewmaster15]

Hi larry,
I'm not sure I follow all your ideas here, but let me ask this..

. In the case of F1 HeckelXBlue/Brown the Heckel 5th bar is dominant coming from the Heckels that always have it. I believe these hybrids are not very important due to their reduced viability.

Why do you think they are hybrids that have reduced viability?

-al

[Apistomaster]

Hi Rod,
I respectfully disagree with you.
I believe that a 5th bar being prominent in just a few per thousand wild discus does not require a recent hybridization with Heckels.
I think this trait while characteristic of Heckels NOW, goes far back in their evolution. There were certainly ancestors to Heckels as nothing arises from out of nowhere as a full blown species suddenly.
Heckels may be the ancestors of discus still extant or merely the oldest existing descendant of older forms.

Particularly what I find puzzling in the grand scheme of things is that the geological formation of the Amazon basin and Orinoco drainages only after the uplifting of the Andes and Guyana Shield. Discus are found far West of the Rio Negro upstream. For all we know the ancestral discus formed upstream and then distributed itself down stream, each extant population then speciating into the forms we see today, specialized for it's particular range.
This scenario seems more plausible to me than than radiative speciation from the Rio Negro up and down stream.

[Apistomaster]

Al,
I forgot to respond to your questions regarding viability of Heckel Hybrids.
1. I have always felt they were too distantly related to the other discus for hybrids to produce other than mostly "mules".
2. Heiko Bleher working with others including Schmidt-Focke found them inviable by F4 or usually sooner'
3. Natural Hybrids have not been successfully bred in captivity
4. I always felt Dr Schmidt-Focke was the best authority on discus before ever hearing of H. Bleher
5. As a matter of faith I believe that more DNA work will substantiate the above.
6. I see this as parallel to crossing altums with scalare.
Larry Waybright

[brewmaster15]

Hi Larry,
I guess we will have to see what happens down the line here with this project. I am afraid though we share the same strong interest in the wilds.. Our ideas deviate substantially...which is not a bad thing...makes for interesting discussion.

I hope that as time progresses we can substantiate some of the thoughts about Heckels evolution and reproduction.

-al