Feature Archive 5 - 1st quarter 2001
New varieties in Shaded Mice
The himalayan colour pattern is one of the oldest mutations among fancy animals the world over. Not to mention one of the favourites. This variety is found in cats, rabbits, mice, cavies, rats, Hamsters & gerbils.
Himalayanism is a colour pattern almost instantly recognizable, even by those people who have never themselves kept any type of 'fancy' animal as a pet..
The characteristic look most people think of when you mention the words himalayan/siamese, is one of pale body with darker points. However there is much variation as to expression, between the different species. The rabbit, displays with pink eyes, coloured points and a white coat, as does the Cavy, yet the cat affected with this gene, the Siamese, has blue eyes, coloured points, but a pale sepia shaded body.
In some species not all of the points are coloured. In the Hamster only the skin of the ears is pigmented, and expression is even more limited in the case of the Himalayan affected gerbil, where only the tail displays some coloured hairs.
The Rat & mouse both have two separate expressions of this gene. Siamese and Himalayan. Both these varieties have colour in all the respective points areas. Siamese have a shaded body, whereas Himalayans have a White body. This difference in body colour stems from the Himalayan variety being heterozygous for albinism.
The age at which colour develops on the points is very different in each species. About the only characteristic that all of these do have in common, is that they all have a complete lack of pigmentation at birth.
Carawatha have had Siamese mice from the very beginning. In fact it was a little seal pt. Siamese girl who started us off on the whole mouse craze. When we obtained little "Thai" from a friend, she was pregnant to one of the seal pt. Siamese males in the group we were re-homing for him. We ended up keeping a pair from her litter, "Carawatha Siam" & "Carawatha Zhar", and these two started the line of Siamese we have to this day.
While we have bred a small number of Himalayan mice along the way, I personally prefer the look of the Siamese mice. While we only had seal pt..'s for a few years there, It's been a rewarding challenge breeding the different colours in. We now have siamese in Chocolate, Blue, Lilac & all of those in Agouti point too (Pic A5.1). Not too long ago, we bred a very different looking points colour, that we believe to be Silver. This silver pt. male "Carawatha Silvano"(Pic A5.2) will need to be testmated to prove if he is indeed silver.
A few years into our mouse breeding, we were eager to try and develop a new variety if we could. Having had a lot to do with the cat fancy for most of my life, we decided to try and breed a 'Balinese' type of mouse, like found in the cat..(Pic A5.3) This was to be the single simplest variety we have ever attempted. Two litters later, we had our first Balinese (Longhaired Siamese) mice.
We bred our longhaired self black female "Carawatha Inca" to our specially selected, longhair carrying seal pt. Siamese Stud male, "Carawatha Rha", and were very pleased to find two Balinese males in the litter. "Carawatha Rookie" & "Carawatha Tenderfoot". These were the start of our Balinese line today.
Since this first accomplishment, we have gradually bred the Siamese type into, and mixed it with, other breeds and varieties of mouse. Siamese Tan (Siamese Fox) (Pic A5.4)
Marked Siamese(called Trimese in some places)looking like tricolors.
Together with our purebred lines, and because we had pretty much every variety of mouse available in Australia, we did a fair bit of cross breeding between the varieties, to break up patterns, and to create attractive looking 'pet' mice. Along the way we came across some exquisite looking mice, that could only best be described as having the same look as a Burmese cat. (pic A5.6)
After looking around for any similar mice, we found a site on the web that had a pic of a mouse that looked identical. These were in the US and being called Siamese Sable. Since then we've bred many litters like these in a range of colours.
It wasn't long before we started getting these Burmese with longhaired coats. So because we were the only Rodentry breeding them, we applied to ANRA to have them standardised, and they were named Javanese. Again this name is after the cats of similar appearance.
Because one of the main genes responsible for Burmese and Javanese mice is the ch or 'himalayan' gene, the pigment expression in these varieties is slightly less in intensity, than the full strength expression of the self colours. This is recognisable in that each colour takes on a subtly paler tone. This also effects what appears to be a slightly paler undercoat, when in actuality, it is a darkening of the tips of each hair. This is in keeping with the similar effect on points. Thus Burmese and Javanese mice exhibit darker toned nose, ears, tail-root and to a much lesser degree, feet. These points are more noticeable on younger animals, tending to fade with age.
Because of the paling effect on colours, a genetically black burmese, will look very dark brown, thus it was decided that to call it a black burmese would be misleading because it doesn't look black. In the cat fancy this type are called brown burmese, but the name brown was also found to be misleading, as people's mental picture of a 'brown' mouse was that of standardised chocolate. So the name Seal Burmese was chosen because of the very similar colour and hue to the self seal mice.
This is the only name difference though, with all the others, chocolate, Beige, Blue, etc. being called the same as their self counterparts. Burmese & Javanese mice have not as yet been bred in any agouti varieties, only on the non-agouti(or self) background.
Seal is a colour only recently standardised by ANRA. Although Seal behaves as black genetically when bred, the phenotype is most distinctly different. Being a deep velvety sepia brown colour, it's believed this variation is either caused by polygenes, or heterozygosity for albinism. The latter is a possibility, given the fact that himalayan variety mice, are affected this way.
We have thought about trying just one mating with an agouti based colour, to see what type of pattern/colour differences the burmese type would cause on an agouti background. It could be exquisite or it could just be a messy pattern. Whatever the outcome, it's almost a given that they'd be an unusual looking variety. & If they did turn out to look messy, then we'd just have to keep every single one of the bouncy little babies. In fact, now that I think of it, maybe we'd need to try this with all the agouti based colours, just to see if maybe a different colour wouldn't show up completely differently, and if they all turned out the same, then I guess we'd have to keep all those babies too.*grin*
Written by Y. Hemberg.