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Marten sable

Written by Sarah Yeomans, Blackthorn Mice
PictureMarten sable bred by Sarah Yeomans
Genetically, marten sables are sable combined with the chinchilla gene: Ay/at cch/cch. In other words they are genetically a red fox, but the chinchilla gene bleaches all red pigment. They are a very rare variety so if you wanted to take them up, you would probably have to make them from other varieties.To make marten sable you need to cross a sable or red with a black fox, which results in sables and black tans carrying the chinchilla gene. The sables from this litter are bred back to black fox and marten sables will, mathematically speaking, make up 25% of the resulting litter, the other 75% being sables, black tans and black foxes.

In reality this beautiful variety is extremely difficult both to breed and to show. Firstly, it has the problems of the Ay gene; a tendancy towards obesity and poor type. For some reason, the chinchilla gene lessens the effect of the Ay gene in these respects, but the problems are still there. Secondly, this variety does not breed true and black foxes occur in every marten sable litter, which reduces the breeder's choice for the next generation of breeders. The foxes thrown by marten sables are unlikely to be of show quality. Thirdly, marten sables are prone to all of the faults of the sable, which makes it a particularly difficult variety to show. Sables of any kind are prone to moulting into distinct patches of colour and pale faces are a common fault.

PictureMarten sable bred by Sarah Yeomans
I have found that, like with marked varieties, marten sable litters are extremely variable in appearance; in most cases there was only one marten of show quality in the litter. When I say "show quality", I mean of sufficient quality to enter, not necessarily win! If you are lucky enough to have a good one, you only have a short time to get the mouse to the show bench before moult sets in. I remember I had three stunning bucks kindled in October, the best I'd ever bred. By the time they were weaned in late November, the next show was eight weeks away. Six weeks later the moult started and, by the time the show rolled round, my previously beautiful bucks were unshowable as each one had a very dark brown 'cap' between the ears. Breeding stock can't be selected for some weeks after weaning as the colour and contrast deepens with age. It is also helpful to wait for the first mice of the generation to start to moult, so that you can avoid breeding early moulters in the hope of breeding marten sables that can be shown for a longer time.

When outcrossing the marten sable the only real option is black fox and the marten sable breeder is best off keeping a stud of exhibition quality black foxes alongside the marten sables. Good quality black foxes (at/at cch/cch) need to be used regularly to improve the contrast between the dark brown top and the pure white belly of a marten sable. If marten sables are bred together for too long the top colour pales and the belly becomes yellowy cream. For improving size and type a PEW (a/a c/c) can be used, which results in a litter of old-style creams (Ay/a c/cch) and unstandardised sepia/mock chocolate foxes (at/a c/cch). The foxes are useless, but the creams can be bred back to black fox to get back to marten sable.

PictureMarten sable bred by Sarah Yeomans
Varieties to avoid breeding into marten sables include everything but black fox and, if needed, PEW. A fox of any colour other than black will introduce diluting genes that will make the resulting marten sables too pale in the case of chocolate and unstandardised in the case of blue. Using a tan variety ruins any work already done to make the marten sable bellies pure white, and using a non-tan or non-fox variety results in martens with only one tan gene. If martens with only one tan gene are bred together, creams and self blacks will appear in the litters, none of which would be good enough to show. Introducing the pink eyed gene, say from a self silver or an argente, results in pink eyed creams (Ay/* cch/cch p/p) and pink eyed cream foxes (at/at cch/cch p/p) in subsequent litters.

For showing purposes, bucks are usually better. The short cycles of hormones in does means they are prone to moulting much more often and more dramatically than the bucks. Because the Ay gene causes weight gain (and because bucks are generally lazy animals) bucks should be run together for as long as possible and then, when fighting starts to break out, kept constantly in with does to keep them fitter.