This article is from the Fall 1999 AFRMA Rat & Mouse Tales news-magazine.

By Nichole Royer

Beth Signor, Rio Rancho, NM
Q I’m a member of AFRMA who breeds mice, and I’ve had a color turn up that doesn’t fit any of the associated descriptions, so I was wondering what it might be. It usually crops up when I cross Fawn with Golden Agouti. I’ll get Fawn, Argente, and Agouti, and a color that is golden with a bluish undercoat only along the spine, and eyes are black. It’s really rather attractive, especially in Satin, and I wondered if it had a name or if anyone else had been raising these.

A Unfortunately, it’s very difficult to figure out the color of mice without seeing them in person. Usually, I would suggest sending us a picture, but the orange group of colors never come out right, and I still couldn’t see the undercoat. Taking a guess (and a wild one at that) I would say you have Fawn mice with some colored undercoat. I’ve seen a few of these, but they aren’t really common since most people breeding them are selecting for no other colors. One other option is that you have some sort of Sable mouse. They can range from a sooty Fawn color with just a little bit of dark color on the spine, to a good Sable with dark along the spine that gradually fades at the belly. I asked around to see if anyone else had any ideas and no one could really think of any. Perhaps if you send me detailed info on your breedings, I could figure out genetically what is going on.

Karl D. Bailey, e-mail
Q The question I have is about my proposed next breeding pair. I was wondering what type of colors and markings I might expect from a Cinnamon Hooded male and an English Irish Champagne female.

A Without knowing a more extensive background on your rats, you should get mostly Agouti babies out of this combination with a few Blacks possibly thrown in. If your male or your female are carrying other recessive genes, you might get a few other oddball colors as well.

Marking-wise they should run the gamut . . . everything from English Irish to Berkshire all the way to Hooded. Probably nothing marked well enough to show, but a fun mishmash of cute markings none-the-less.

Are your male and female related? If they are, you may well get more Cinnamons and Champagnes as well as Lilac and Silver Fawn.

Shannon L. Nilsson, Jacksonville, OR
Q I am trying to stabilize a Seal Point Siamese line of mice. Unfortunately, my foundation male is quite old, and I’m not sure I’ll ever get a useable buck by him. The best youngsters I have by him out of a Seal Point Siamese doe are just 3 weeks old and are not showing any ear/nose markings yet. How long does it take for young to show Siamese markings if they’re going to?

A Young Siamese mice often do not show their points for some time. The Siamese pattern is temperature sensitive resulting in fur that comes in darker on the coolest part of the mice. When born, of course, the mice have no hair. As their hair grows in it usually comes in all one color since the baby mice are kept at a constant temperature in the nest. Usually, they range from off white/ivory to beige in color. It is not until they moult for the first time at 5–6 weeks that you see the points, and often the color darkens with every moult for several months. If the babies are born during the summer, or if your mousery is warm, they may appear to be white for some time.

Getting more Siamese from your does should be easy. The best thing to do would be to breed them to a really nice Pink-Eyed White male. The resulting babies will be Himalayans. Breed these babies together and back to their mothers and you will have more Siamese.

If you have one, you can also breed a good Black Self male to your females. The resulting litter should contain a number of nice Black Selfs. Breed them together and back to their mothers and you will get more Siamese.

Q Some time ago I acquired two black and white rats from a pet store. One of them is very shiny, so it must be a Satin. The other has a normal-looking coat.

Recently, I bred these rats together and they produced a lovely litter of 10—5 black and white and 5 cream and white. Strangely, only one of the black and white babies is shiny and none of the cream ones are. Why didn’t I get any cream colored Satins? Are these even really Satin rats?

A Satin rats are rather rare, and they really haven’t gotten out into the commercial pet market (thank goodness). Their distinguishing feature is a coat that is made up of long, fine, almost translucent hair which is a true genetic mutation. This hair gives the rat a shiny appearance all over, both on top and on the belly. This type of hair can be found on any color rat, light or dark. Almost always it will cause light or white animals to take on a yellowed or off-white appearance.

Unfortunately, it is very easy to mistake dark colored rats with beautiful healthy coats for Satins. Though these rats are almost stunningly shiny (often as much or more so than true Satins), their stomach never develops the shine. Their hair feels and looks normal (just shiny) and is not particularly longer or finer than other rats. Also, the trait is not passed along to their offspring in a normal recessive fashion, and light colored offspring never develop it.

The best way to tell if you have true Satins, is to watch the babies when they are very young. At about 1 week of age, Satin rats will have kinky or wavy whiskers (very different from the curly whiskers on Rex babies).

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