Building a colony, best way?

[Joby]

I want to build a colony of zebras and wondered what the best way is to go about it. I have no problems buying young fish and watching them grow (isn't that half the fun of keeping fish) and see what ratios I get and hope there is at least one of each but would it be best to try and get youngsters from different bloodlines from the outset?

I breed bettas and know I can go to F9 before out-crossing but not sure what the guidelines are for zebras

I'm also a little worried as to how to source them with the current questionable Ebay auctions that pop up as far as I see its the only place they become available so does anyone have a checklist I can follow

[mistern2005]

I think this is an excellent question. I'd be very intersted to hear some of the responses.

I purchased my zebras a very ting little fry - probably about 1 inch in length. I originally got 2 and one died . The I purchased 6 more from the same breeder and he said those 6 came from three sets of F0 parents. There wasn't a way to tell if the original one was from yet another set of unrelated parents.

Seven of the original 8 are alive and well today. They are probably about 2 years old now. It has been great fun to watch them grow up and I get a lot of satisfaction when I look at thier "baby pictures" to see how much they have changed.

My advice - take a lond time, be very patient, send PM and make posts to try to make contacts, and try to diversify your gene pool as best as possible.

[TwoTankAmin]

Here is the thing: Trace the process and you realize there is no way to guarantee diversity 100%. I would say there is no way to know at the initial point of capture in the wild if any batch of zebras are totally unrelated or all brothers and sisters. So one has to start by making assumptions that can not be proven in terms of whether the fish are unrelated, partly related or unrelated.

Then the fish got shipped to various importers who then resell them. There is simply no way to know if two buyers who are geographically far apart are getting fish related or unrelated.

I bough a colony of 13 adults from a gent who had acquired them from three different sources well before the ban went into effect. He made a best effort to have a mixed genetic pool, but as to how diverse it is, there is no way to know without actually doing genetic testing.

The only thing I know for sure is that I have multiple males and females and that I have gotten multiple spawns which must have come from different males and females. I know this because I they occur close enough together that two dads are on broods at the same time and I don't believe a single female could have "recharged" soon enough to mother both. But I do not isolate my spawns, in fact I leave many in the breeder tank to be fished out later. I believe many who breed this fish do something similar, although some folks do document and segregate theirs.

When I sell fish to folks I try to insure the buyer is getting a varied gene pool by including fish of different sizes with the goal of their being fish from more than one spawn going out. However, I can never guarantee that there is not a common father or mother involved.

Given these facts, how can a buyer manage to amass a colony with the intent of maximizung genetic diversity? It seem to me that it requires one do so by going to more than one supplier. The buyer needs to try to determine when and from whom they acquired the parents. If two sellers both got their fish from the same supplier, this will lower the odds they are not related. But if you can find multiple seller from disparate geographic locations who came by their fish at differnt times and from different suppliers, the odds are relatively good that the results will be a genetically diverse group.

One interesting observation- when I got my group I asked Barbie about the genetic diversity issue and at what stage I should be concerned about introducing new genes if I was able to grow out offspring to spawning age and get F2 etc. etc. She was of the opinion that it would be at least 5 generations. Given the 2-3 year time horizon for each generation to mature to a decently successful spawning age, it would take anywhere from 10-15 years before I should be concerned.

At this stage of things across the globe, I think most of the tank raised fish being distributed are almost exclusively from wild caught parents. This means there should be a pretty good genetic diversity at work in general and that buying from multiple unrelated sellers who acquired their fish from diverse suppliers at different times, as indicated above, there should be a high probababilty of obtaining a genetically diversified group with which to work.

[Jamie24]

Good post!



J

[Zebrapl3co]

This is a really tough topic.
I do agreed with TwoTankAmin on many points. But one thing I disagree on is that, I think by the time you hit the 5th generations, it may have been too late to do much to undo the damage (defects).
Also, I suspect that there is a high probabilty of interbreeding in the wild as well. Until we get their dna propertly analysed, everything is a guess work.
One of my initial quest work was that I assume that the zebras themselves would sort this out by not wanting to breed with their sisters or borthers. But I am beginning to have doubts that they might not give a danm and mate anyway.

[Joby]

Many thanks for taking the time to reply

And I have to agree, fish have no morals

[TwoTankAmin]

Genetics is not my strong suit. However, I find this information which comes from The Xiphophorus Genetic Stock Center site is interesting. The final paragraph I have highlighted in blue is what I found most amazing.

Introduction

Genetic stock centers are priceless resources in scientific research. Genetic experiments often require that special strains of genetically identical animals or plants be used to assure that results can be repeated in any laboratory and that differences are not due to environmental factors or to random variation found in almost any population of animals. Among vertebrates, genetically identical animals most often are produced by inbreeding for many generations between brothers and sisters; in each generation, about one-half of the genetic differences between the parents are lost. It comes as a surprise even to most scientists that one of the oldest and best defined groups of genetic strains consists of livebearing fishes of the genus Xiphophorus , the platyfishes and swordtails familiar to the tropical fish hobbyist.


In the 1920s, the American biologist Dr. Myron Gordon and German biologists Haussler and Kosswig independently discovered that hybrids of a particular strain of the platyfish Xiphophorus maculatus and the swordtail Xiphophorus helleri developed cancers virtually identical to malignant melanomas in man. They traced the origin of these tumors to pigment cells of a platyfish color pattern consisting of black spots on the dorsal fin. Genetic studies demonstrated that melanomas developed only in hybrids which had replaced both copies of a platyfish regulatory gene with swordtail forms which could not control proliferation of the platyfish pigment cells. This animal model was one of the first to prove that some cancers were inherited diseases; after 65 years, these fish still are used in cancer research in the United States, Germany, Canada, and Japan.

Dr. Gordon realized that to identify precisely the genes responsible for development of cancer, genetically identical platyfish and swordtails would be needed. Therefore, in 1939, he established the Xiphophorus Genetic Stock Center, housed at the American Museum of Natural History and the New York Aquarium until 1993, when transfer of the stock center to Texas State University | San Marcos in San Marcos was completed. During its 55+ years, the stock center has been directed by Dr. Gordon and Dr. Klaus D. Kallman in New York, and currently by Dr. Ronald Walter (Texas State University | San Marcos).

Several of the original genetic strains of platyfish and swordtails developed by Dr. Gordon in the 1930s still are available today; they are virtual genetic clones, the products in some cases of more than 80 generations of brother-to-sister matings.

From: http://www.xiphophorus.org/xgsc.htm#Stars

[dave]

Genetics is not my strong point, but my understanding is that if you breed a perfect specimen of any species to a perfect specimen of a brother or sister, the likelihood is that the offspring will not have what we perceive to be abnormalities.

Breeding related fish will emphasise any unusual characteristics that are present.

This is utilised by the breeders of fancy guppies, discus, bettas etc.

The amount of culling required to fix a particular trait is very high. The same I guess will apply to the wild form.

If equating liveberears to Hypancistrus is valid I am not sure as there is no long term data on inbreeding Hypancistrus.

Livebearers are also unusual, for example if you take a tank full of virgin female guppies, you will get tanks full of female guppies which are clones of their mother.

Swordtails are known to change sex, so theoretically it is possible to breed what were originally brothers.

In addition many Mexican Livebearers have a very limited range, evolution has probably equipped them to deal with inbreeding.

Personally I wouldn't take the chance with L46 or any fish really.

Take care

Dave

[dave]

Just a quick note.

Due to the availability of, or lack of availability F1's and F2's should be just fine, but as more become available it should be possible to introduce new blood lines.

Take care

Dave

[Joby]

Very interesting reading again, many thanks and agreed about the lack of supply and time taken to reach F2 F3 etc. I guess time will tell but in the mean time try and source from at least two different locations would possibly be a good idea it seems if possible

[TwoTankAmin]

The point of my post was not to equate livebearers and zebras. it was more to share the fact that it is possible somewhere in the fish world for brother and sister matings over many generation no to result in genetic abnormalities for sure.

However, if Dave is on the mark in saying:

In addition many Mexican Livebearers have a very limited range, evolution has probably equipped them to deal with inbreeding.

I would then wonder if the zebra's range is not similarly limited, and thus if they too might not be "equipped" in a similar fashion.

And this brings me to another commonly discussed issue re zebras, subnoses. The other night I was thinking about plecos and current. Plecos are adapted to live in waters with current often a very strong current. Having watched the plecos I have in my tanks, I have observed that they always seem to suck onto things facing head first against the current. Now thing about the shape of a plecos head and its relation aerodynamically to dealing with current. I think that the slope of the head is "designed" to minimize the effect of current in terms of allowing a pleco to remain attached in the face of strong flow.

A snub nosed zebra has a face which, rather than streamlining things in terms of flow, would actually have the opposite effect. Now If I am correct about this, it stands to reason that a snubber would have to expend a lot more energy staying in place as well as swimming against the current. And from there, it would also seem plausible that this disadvantage would likely doom most snubbers in the wild to an early demise.

However, in an aquarium, even when we run strong current, a snubber has a pretty good chance of surviving because of the limited area combined with an ample supply of food. And this made me wonder whether a snub nose might not actually be a genetic phenomena after all?

They say a little knowledge is a dangerous thing, and a little knowledge is what I have, so I am likely way off base here.

[Joby]

A very good point, taking them out of the wild and placing in the aquarium has to have its effects

[Zebrapl3co]

...And this brings me to another commonly discussed issue re zebras, subnoses. The other night I was thinking about plecos and current. ...
... And this made me wonder whether a snub nose might not actually be a genetic phenomena after all?

However, the fact that snubnose is a genetic traits or just a result of the fry pressing his face against a square cave, have not been established.
I tend towards that fact that is a behaviour defect rather than a genetic one. Another behavoiur traits I observe is that they snubnose tend to stay onthe bottom of the tank rather than suck against the side. I have a suspicion that there might be a way to un-snub them if it's a behavour problem.

[dave]

Regarding a limited range.

Daniel Machado who works for the IBAMA, and is also a member of this site, perhaps could give an indication of the range of this fish.

In addition Sojapat who used to post on this site, regularly imports fish for his shop, directly from the Xingu and Tapajos. He has also visited some of the places the L46 are collected, I have seen the pictures.

The latter is very much against inbreeding, I can't speak for the former.

As for inbreeding, take Skiffia Francescae, extinct in the wild, a very limited original range. The colony Chester Zoo maintain, while they look supeficially OK, to quote the head of the aquarium there "they are gentically knackered"

I now know Sojapat because of L46's, and I get the impression from him that the range is not that limited.

Chester Zoo who I have donated fish to (Specialise in breeding endangered species) , have declined some of my related young but are more than happy to accept unrelated fish.

While I am prepared to listen to the limited range theory and inbreeding is acceptable, I would be interested to know on what it is based?

Take care

Dave

[Zebrapl3co]

In addition, another point I'd like to point out is that in an event of a genetic deformtie, it may not be so visible when it happened. Say on your F3. You could've been walking down several generations before it becomes so obvious that you start to see this happening to all your fry. Like in F5 or F6. By that time, you would have a doomed senario.