Amphibian Inbreeding

[alex]

Does anyone have an opinion on this topic? Inbreeding is a serious problem with mammals, but is it such a problem in reptiles and amphibs. With mammals, inbreeding can cause mental retardation or mutation because of a recessive allele grouping, but since retardation and other mammalian problems don't exist in amphibs, is it a problem. Obviously it could result in albinism, luecisticism (sp?), size change, etc. Do you think there is any serious detrimental effect, it might actually have a positive effect by adding new animals. Just wondering, Alex.

 

[mark]

Alex it takes a long time for inbreeding problems to show up in amphibians and reptiles. To begin with they generally don't have large home ranges and in the case of pond breeding amphibians usually breed in the same pond year after year.If inbreeding was a real big problem parthenogenetic species wouldn't exist. (For those that don't know parthenogenetic animals are all female species that reproduce without male.)Some out crossing can be beneficial but if the animal is not from the same vicinity you may lose the traits that make that animal unique to that locality. Some animals only exist in captivity,axolotl come to mind,and the lack of fresh genetic stock hasn't seemed to have hurt them yet. Mark

 

[kyle]

http://home.hetnet.nl/~dresens/engelscarnifex.htm

Interesting white T. carnifex as well as some information about weakened genetics after some simple inbreeding.

 

[edward]

To put it bluntly it depends. It depends if there is a lethel gene available that can become isolated within the population.

If you read through the link Kyle listed there is also a method in there that through line breeding (a form of inbreeding) that looks like it allows you to breed the gene out of the population...

Many amphibian and reptiles in captivity have come from limited breeding stock (some population less than 7 founders) and yes in some of them there have been issues via massive inbreeding (such as San Fran garters in Europe) however in others there has been little or no problems seen despite large amounts of inbreeding (Brazil nut poison dart frogs).

Ed

 

[alex]

If you think about it, it must happen in the wild. Most mammals have the ability to recognize their young to some extent, but amphibians don't raise their young, so how would they. Like it was said above, sals always return to the same pond in which they were born, so that would certainly create a possibility for inbreeding. Like Ed said, some of the breeding populations are just to small for their not to be inbreeding. Alex.

 

[mike]

There are several examples of inbreeding in wild amphibian populations associated with small, fragmented populations. Some of the clearest examples are work by Trevor Beebee on Bufo calamita and B. bufo populations. Small, isolated populations have been shown to have both reduced genetic diversity and reduced individual toad growth rates and survivorship. This highlights the importance of protecting not just single ponds and some adjacent upland habitat, but larger areas encompassing many smaller populations to maintain large overall populations.

Mike