BULLDOG Fry- Genetic Or Environmental

Everything you ever wanted to say about "Zebra luvin", but didn't because you thought everyone would take the mickey! Plus general topics for discussion including everything from what you feed them to your personal experiences.

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Ed_R
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Post by Ed_R »

Ah-HA!

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Post by Tom2600 »

Firstly, its all still open to debate UNTIL two bulldogs are bred together! I'm sure this is just a matter of time. I just hope an expert breeds them as an experiment and reports back their findings.

My own personally opinion is that this feature is likely to be a genetic defect for the reasons I have mentioned in previous posts, but obviously this has been be proven, so I completely accept it could be environmental.

If I breed fish and they show any defects (no matter what the cause) I cull them at an early stage. With Zebras, obviously breeding them at all is very rare so NO ONE would want to cull any, even if they have two heads and four tails! :wink: I would find it hard to cull a young zebra no matter what it looked like. HOWEVER, I would not allow a deformed Zebra to leave my tanks. Wandj has already encountered someone making a quick buck of the back of Zebras. All breeders of fish should act responsibly, some will not, but that is unfortunately human nature.

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Post by Ed_R »

So BREED THE BULLDOGS AND SEE!!!

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Post by Tom2600 »

Tell you waht Ed, you find them, send them to me, and I will try to breed them. :wink: Until then we'll have to wait and see. This one might never be solved.

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Post by Ed_R »

I'm thinking that the only answer we're going ot get is the oen we come up with on our own. You seem to have your mind made up, I am willing to listen. BAsed on previous experience, both cause scenarios that have been described run true in other species- the genetics stuff is everywhere and the deformed head from embryionic trauma ( in this case not being able to split their shell ) happens in many other species as well.

Proof it would never be, but if the evidence shows that bulldogs happen more often in eggs and fry that are taken from the father prior to hatching than as happens with fry left with their father for the duration and for days beyond, it's a good indicator that the egg-shell problem is more likely, as genetics have already taken hold by the time they hatch.

IF i'ts genetic, it would be somewhat consistent in the same pair from spawn to spawn. Where are those reports?

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McEve
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Post by McEve »

It happens to other Hypancistrus species as well? That's certainly a strong indication for it being enviromental! Can somebody confirm that it happens in other species as well?

I raised a clutch from eggs, but none of those were bulldogs. This is not conclusive though, as it's only one hatch. And I understand Barbies speciments were hatched by the father? The only one that can give an answer to if this is correct would be Barbie though, as I might have misunderstood that. But if so, then this is not conclusive either, as it might be because the father was inexperienced, and didn't help those out of the shell....

I think what should be done is try to gather more information, try and find out if the bulldogs we see were either hatched by the father, and if so, was he a first time dad, and also, were they hatched "artificially". And also, did somebody get bulldogs from the same pair several times.

I speculated earlier in a post if it could happen during the egg hatching process, I don't see that as completely unlikely, and when a very experienced breeder think so, then it's very likely that this is indeed the cause. Nothing would be better! Then we don't have anything to worry about.

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Post by Barbie »

Yes, this is something I've seen in my L260 fry also. I had one in my first batch that had a snubbed nose. I had rescued it from the main tank after it had been kicked out, or fallen out of the cave, and I thought I injured it. (I actually am pretty sure I did whatever damage that occurred, but it looks identical to the damage I see on the few snub nosed zebra fry I have from my first batch or two now.)

As I've thought more about it, I know that my big male REALLY wedges himself up onto those fry when I go peeking in there with a flashlight. We might find some correlation between people that can leave the dang fish alone to do their business and the ones like me that just have to be pokin around in there to see what's up, also ;). At this point, I'm almost tempted to keep all my snub nosed guys, throw them in a tank and let them spawn. If they only had snub nosed fry in the first couple spawns, and then none on the next ones, it would definitely be an environmental factor, just like with the perfect ones.

Then again, we have a few members that have ended up with them. If I was in their position, I'd breed them. If you discover you get a disproportionate number of deformed fry after the males have had a couple tries to get things figured out, then you'd have conclusive proof. Otherwise, I'd treat them as something that was injured. That will have no bearing on their genetics, IMO.

There will be no way to know until someone gets in and does actual studies to figure it out. I'm just glad to see I'm not the only person that thinks it probably isn't genetically related. ;)

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Post by McEve »

What I find strange though, is why it doesn't straighten itself out? Most animals that get squished or bumped when they are born get straightened out as they grow. They do this just because their bones are so soft and aren't finished developed.

I know it doesn't happen to all fry that are left to themselves to hatch, And it appears to happen to some that are left with their father.

I'm open to both possibilities, there's no prestige in being right or wrong in this for me. I'm just interested in finding out what's causing this to happen.

Edit:

And no, I don't think it happens only to people that can't leave them alone, I'm there with my flash light, and IR ligths and what not :lol: I don't think it's your fault

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Post by kgroenhoej »

It happens in other species as well.
I've seen ancistrus f1-fry with this defect.
And there's a picture in the New L-numbers of a wildcaught L18-"bulldog".

I'm with the egg-shell-theory. I think that the egg is sometimes to hard to crack for the fry (sometimes alone and sometimes with the help from farther). The next thing to figure out is why the egg-shell gets to hard - maybe the food?

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Rob
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Post by Rob »

kevin

Cheers for that, and it would certainly expalin the mutation's (or abnormality ,may be more appropriate after your previous post) absence in the wild caught fish.

To be honest it is the type of answer I was hoping for, as to try and maintain a clear strain and gene pool with captive breeding would have been near on imp[ossible otherwise.

So... for the moment, apart from the physical deformity it would appear the fish cannot infulence other generations. Although it should be something we monitor closely, just to ensure that a genetic mutation cannot be passed from generation.

anyone fancy a guess on the the crmiped pelvic fins!! :lol:

Thanks again Kevin

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Looking for Snub-nose Hypancistrus zebra.

Post by kkorotev »

It seems from the time stamps on your posts that most of you are on the other side of the world from me. This is unfortunate because I believe I would like to pick up the gauntlet on this "Breed the Bulldogs" challenge.

I suspect young adult snub-nose zebras may be hard to find, but if any of you know someone over here (continental US) that has one/some, I'd like to talk to them. I have no use for fry or youngsters (I have some, thanks.) I will be willing to buy or trade for them but not at the current retail rate...I'm not THAT curious.

Pass the word if you like.
kkorotev@sbcglobal.net

Kevin Korotev
Milwaukee, Wisconsin USA

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Post by Ed_R »

I think they mystery is a lto closer to being solved but we still don't have PROOF, and even breeding bulldogs won't be conclusive, will it? We haven't nailed down a cause, and the only way to do that is to breed them- bulldogs AND non-bulldogs.
SO, how do we prove it with breeding? Do everything else the same- diet, water temps, water parameters- especially hardness and pH and temp and DO, as these are shown to affect egg hardness in other species of fish, like angels and cichlids- and remove the eggs from the father in some batches and not in others. Then do the counts. It'll take a large number of spawns, I think and ther will never be a 'Eureka!' moment, but we'll have a large amount of research and controlled environmental information to go by.

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Post by KenW »

I agree inorder to get to some educated guess to the reason behind the bulldog abnormality a large number of breeding and research will be required.
Here's another thought along the lines of genetics, could it be that the abnormality is a result of inbreeding. Even with wild caught specimens, we have no idea if they are siblings. In an aquarium setting even a breeding group could have siblings and non-siblings. Just thinking out loud. I was also thinking, could it be that when the males are tending to the eggs and occassionally kick one or two out he is intentinonally getting rid of babies that are not developing correctly. Thus in the wild the discarded would not survive but in the aquarium they survive due to hobbyist intervention or lack of predators. I'm probably wrong but just a thought. Maybe I'm giving to much credit to our male zebras.

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Post by Ed_R »

I think inbreeding can be counted as a genetics issue, to be honest. Your point of the male sensing and eating the deformed babies is what we are essentially talking about. I think.

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Post by Tom2600 »

Ed_R wrote

"...Proof it would never be, but if the evidence shows that bulldogs happen more often in eggs and fry that are taken from the father prior to hatching than as happens with fry left with their father for the duration and for days beyond, it's a good indicator that the egg-shell problem is more likely, as genetics have already taken hold by the time they hatch.

IF i'ts genetic, it would be somewhat consistent in the same pair from spawn to spawn. Where are those reports?..."

****************************

I have not made my mind up at all! I just have my own thoughts, I am open to discussion. Thats the only way to try to move things forward in the world.

However, with regards to genetics, if the bulldog gene is recessive (which is almost certianly is, IF it exists) then the same pair will not always produce deformed young.

I would like to know when the skull of a plec becomes solid? Does anyone know about this development and if it occurs before the fry emerges from the egg sac? This would help in targeting whether this is the cause?

I also have a proposition. Could the fish have a genetic weakness that reduces its ability to break through the egg sac therefore causing the bulldog feature? I.e. therefore the bulldog feature could possibly be indirectly genetically linked? Just a thought.

On the side of the environmental hypothesis, could pollutants cause the eggs produced by the female to be tougher and therefore hinder the fry breaking through? A similar comparison is the DDT poisoning that caused the weakness in bird of prey eggs a few decades back.

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