Advertisements
Aquatic Avenue Banner Tropica Shop Banner Fishy Business Banner
Results 1 to 9 of 9

Thread: inbreeding

  1. #1
    Join Date
    Jun 2002
    Location
    singapore
    Posts
    42
    Feedback Score
    0
    Country
    Singapore

    inbreeding

    Advertisements
    Fresh n Marine aQuarium Banner

    Advertise here

    Advertise here
    Hi

    As a novice in fish keeping, I was quite interested in Killifishes.But as I read through information on local Killi scene, I was wondering on this topic of "inbreeding".

    I believed you guys have spent great effort in bring new species from oversea, assuming the batch of killi eggs is second generation.As more breeding is carry out from the same gene, will the offspring suffer from abnormality?

    Eric Ng

  2. #2
    Join Date
    May 2002
    Location
    Singapore
    Posts
    2,702
    Feedback Score
    0
    Country
    Singapore

    Re: inbreeding

    Quote Originally Posted by woodduck
    As more breeding is carry out from the same gene, will the offspring suffer from abnormality?
    A very good question, Eric. And I think the answer is yes, the fish will show signs of abnormality when there's too much inbreeding. But that will lead us to the next question which is,

    "Why is it that the problem of inbreeding does not happen to killifish like Nothobranchius which live in ponds where no (or very few) new genes are ever introduced?"

    I don't know if my answer to this question is correct as it's just my own theory but I believe the problem of inbreeding can be overcomed if the selection process is very rigorous. In nature, the Nothos live in ponds where the same group of fish has been there for thousands or maybe millions of years. Other than the fact that occasionally, an elephant which has been bathing in another pond may bring a new egg along with the mud that is stuck to its feet, no new genes are ever introduced.

    In nature, there's this process called natural selection where only the strongest males get to fertilise the eggs. Males fight amongst themselves for the chance to mate with the females so only the strongest genes are passed on to the next generation. In such a scenario, inbreeding isn't a problem.

    In our tanks, the process is artificial selection and we the breeders are the ones doing the selecting. Usually, we pick what we think is the best male to mate with the females. We tend to equate "best" with "most colourful" which may not necessarily be the way Mother Nature would choose.

    But we can simulate the same conditions as nature in our tanks by having many males and females in one tank. I call this the "orgy" method. However, unlike a human orgy, a fish orgy allows only one male to do the mating :wink: and he's the Alpha male. I have my Notho guentheries all in the same tank but there's only one breeding bowl inside. And from what I've observed, only the Alpha male gets to use the bowl so although we can never emulate the conditions in nature completely, we can have a more rigorous selection process in our tanks if we let the fish decide for themselves which is the best one among them to carry the genes forward.

    Here's a pic of 3 males facing off each other for the right to go into the bowl. The females are in the background waiting for the outcome of the face-off. You see this quite often in WWF wrestling too



    Loh K L

  3. #3
    Join Date
    Jun 2002
    Location
    singapore
    Posts
    42
    Feedback Score
    0
    Country
    Singapore

    Re: inbreeding

    Hi Loh

    Regarding Nothobranchius, that puzzle me too. From the small pool of water, the breeding cycle must have gone through a few hundreds times!

    There a strange thought from me, the Nothobranchius may have look different 100 years back.

    So, in order to have a health gene, we need to have many male and female?

    Eric Ng

  4. #4
    Join Date
    Jul 2002
    Location
    Singapore
    Posts
    558
    Feedback Score
    2 (100%)
    Country
    Singapore
    For me, I overcome the inbreeding problem by setting up the breeding tank with a group of males and females and add in 2 to 3 breeding bowl.

    This means that the eggs collected would not only come from 1 male but a few. This would somehow reduce the problem of inbreeding. I may be wrong but till now, my fish still don't really show signs of inbreeding yet.

    Anyone would like to comment on this?
    Au SL

  5. #5
    Join Date
    May 2002
    Location
    Singapore
    Posts
    2,702
    Feedback Score
    0
    Country
    Singapore
    Quote Originally Posted by Au SL
    Anyone would like to comment on this?
    I'm not sure if using more than one breeding bowl would overcome the problems of inbreeding. Maybe its different for killifish but for many other species of animals, the gene pool has to be quite big before the species can be sustained. Olaf Pronk who breeds reptiles (and who was here recently) keeps a species of lizard which is close to extinction. Olaf said he has something like 6 pairs of the lizard and they are probably the only ones kept in captivity anywhere in the world at the present moment. But even with 6 pairs, the gene pool is considered too small by scientists to keep the species alive. If I remember correctly, it has to be at least 12 pairs.

    Au, the problems associated with inbreeding are not apparent until the fish have been bred for several generations. It could be yours haven't reach that stage yet. The Notho guentheri's I have were among my first killifish. I think those in my tank now are the F4 or F5 generation and I can tell you they are very different from my first batch of guentheri's. My first batch of Notho guentheri's were so beautiful anyone who sees them would want to keep them. Now, those that are in my tank seem to have less red in their bodies and even the shape of the bodies look different. I know a lot of their beauty has been lost because very few of the hobbyists who visited me want to have this fish.

    However, it could be also that the problem is confined only to certain species of killies. Sia Meng told me he read somewhere that the Notho guentheri's in particular are notorious for exhibiting symptons of inbreeding.

    Loh K L

  6. #6
    Join Date
    May 2002
    Location
    Singapore
    Posts
    2,702
    Feedback Score
    0
    Country
    Singapore

    Re: inbreeding

    Quote Originally Posted by woodduck
    There a strange thought from me, the Nothobranchius may have look different 100 years back.
    It's hard to say, Eric. A hundred years ago, no one took any pictures so its hard to tell if the fish look different now.

    As for small pools of water, although Nothos have been found to exist in puddles of water as small as an elephant's footprint, generally, the ponds which they live in are quite large. I've seen a picture of a pond where a certain species of Nothos were collected. I think it was the Notho kafuensis. I don't know if this is a good comparison but from the picture, the pond looks a lot larger than an average swimming pool.

    Loh K L

  7. #7
    Join Date
    Jun 2002
    Location
    singapore
    Posts
    42
    Feedback Score
    0
    Country
    Singapore
    Quote Originally Posted by timebomb


    My first batch of Notho guentheri's were so beautiful anyone who sees them would want to keep them. Now, those that are in my tank seem to have less red in their bodies and even the shape of the bodies look different. I know a lot of their beauty has been lost because very few of the hobbyists who visited me want to have this fish.

    Loh K L
    I believe the reason why your F4 or F5 doesn't look as good as the Great Great Grand Parents might have due to your WWF breeding method.
    In the RING, only the strongest get to mate....not those pretty face!

    But then again, those in the wild, it seen that all of them are very colourful.You may be able to access this theroy when your friend bring in those wild Killi.

    Red Arowana breeding come from careful selection to achive Super RED!
    Same theroy to killi to have those good look.(I may be wrong as I have not try it out)

    Eric Ng

  8. #8
    Join Date
    May 2003
    Location
    Hougang Singapore
    Posts
    236
    Feedback Score
    0
    Quote Originally Posted by woodduck
    I believe the reason why your F4 or F5 doesn't look as good as the Great Great Grand ....., only the strongest get to mate....not those pretty face!
    The strongest male will usually have the best colours. When group breeding is done, the nothos with the best colour will usually guard the breeding bowl.

    The less colour males are the weaker male, as they know they can never complete with the stronger male, they choose not to colour up as to avoid unnecessary attention.

    Group breeding have been done and tested for killifish to minimize the impact of inbreeding. What I usually do is to select 5~6 nice males, these are supposed to be the few best males among the group, to determine the best, they will have to complete among themselves, thus having the rights to breed in the breeding bowl. Of course the other males will also have their chance to breed but outside the breeding bowl when the best male is busy breeding in the bowl.

    Regards,
    Gwee Sia Meng
    AKA 08742
    SAA 163
    Fish List

  9. #9
    Join Date
    Jun 2002
    Location
    singapore
    Posts
    42
    Feedback Score
    0
    Country
    Singapore
    Thanks for sharing the information, Guys.
    Didn't know the best looking Male is also the Strongest!
    Seem like this analogy doesn't apply to Human.

    Eric Ng

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •