English Blue - the colors of the Rat

Kathrin Guttmann Colors, Knowledge, Breeding & Genetic

The color English Blue with pet rats than most other colors turn out differently in many different tones. Confusingly, there are then at certain shades blue rats even different names, he knows z.B. Slate Blue, Sky Blue, Powder Blue etc.

The origin of the "blue" rat is not fully understood, since the American Fancy Rat and Mouse Association (AFRMA) otherwise reported as the National Fancy Rat Society (NFRS)

The blue rat in England

According NFRS appeared the first English Blue Ratten 1990 in England, wo Joan Breanton, a member of the NFRS, Hooded three Mismarked rat babies in a pet shop discovered, the clear, bright blue color would have, as it had never before been described in pet rats.

The blue rat in the US

According AFMRA became the first blue rats (English Blue is in the United States as American Blue designated) from the AFRMA Mitlglied Sheryl Leisure 1990 also discovered in a pet shop (Report the discovery of the American Blue). this girl, the was named Tinker, was mated with a Lilac Silver Bock bred by Karen Robbins. This mating, together with some other blue rats, that appeared in pet stores, the basis for American Blue Zucht. The first American Blue rat was on 19. May 1991 shown on a AFRMA Show.

The blue rat travel

Interestingly, both sources reported a similar discovery history. Since it is not impossible, but is very unlikely, that the same mutation in two different places occurs almost simultaneously, is suspected, that either British Blues in the United States or American Blues (are genetically the same) had been sent to UK. The AFRMA not reported by the time Import blue rats from the UK, while the NFRS certainly indicates, in the early 1990s blue ratn to have exported to the US. There are American breeders, which are not associated with AFRMA, who report, British Blue rats from the UK to have imported. So it is quite possible, that this color variation actually first appeared in England and then landed in an American pet shop. This theory is also supported, that Sheryl Leisure reported, the Zooladenverkäufer have the rat, she found, as one "Special grey fancy rat variety" (special gray color rat species) touted.

The standard of "blue" rat

Since Blue can occur in many various shades which, can not speak of a standard for the blue rat you. In the following, there are different standards, the circumstances only a specific expression of British / describe American Blue.

Blue (American Blue, AFRMA)

The AFRMA describes the Farbe Blue the standard of 12. April 1992 as a slate gray, that should be as dark as possible and must not have any brown spots or silver hair. The eyes must be dark red or black.

Powder Blue (AFRMA & NFRS)

The Farbe Powder Blue with pet rats was on 7. March 2015 added to the standard of the AFRMA. The color should correspond to a very light powder blue and no rust, contain shades of gray or silver hair. The eye color is dark red or black.

THE NFRS describes Powder Blue as pale, powder blue color with a pale silvery fur base. The abdomen should be pale silver. The color is clearly different from that of a British blue rat. It should be as uniform as possible and no gray haze, having white hair or spots. The eyes are black or dark red.

Sky Blue (AFRMA)

Sky Blue is According AFRMA the original color of the American Blue, as without appropriate selection to Hell (Powder Blue) or dark (Blue) occurs. The color was on 4. April 1998 standardized. It is located between Blue and Powder Blue. The animals must not have any brown spots or silver hair, The eyes are dark red or black. A bright undercoat is a mistake.

British Blue (NFRS)

The NFRS standardizes the dark variant of the blue for pet rats under the name British Blue as a dark steel blue without brown hues. The color should be uniform and match the color of the belly of the top. The coat should be evenly colored blue-gray to the skin.

The genetics of "blue" rat

English Blue is a recessive trait, this means, a English Blue Ratte must homozygous (reinerbig) be for the English Blue Allel.

The locus is in German with d (for English Bue) or. D (for non-English-Blue / Wild form) abbreviated. Confusingly or the abbreviation d. D used in the US to designate Russian Blue. English Blue is there with g (English for Blue) or. G (for non-English-Blue / Wild form) abbreviated. The abbreviation g is however in Europe again for Graphite, the like Russian Blue looks, used. It is therefore advisable, asking exactly in doubt again, what kind is meant by Blue.

Also needs a English Blue Ratte be homozygous for the non-Agouti-(„Black“)-Allele at the locus and, d.h. it must be genetically aa rbrb. In addition to all the other dilution effect, of course, the color English Blue out, so that English Blue den Gencode aa B- M- dd Rb- M- C- P- R- etc. must have, So there must be the dominant allele of the wild type for all other dilutions.

The genetics of different shades of blue

The special feature of the feature English Blue is, that it occurs in so many very different variations. Therefore, some experts assume, that there are one or more modifiers on a different locus, that affect the expression of the characteristic. This assumption is supported by the fact, that a mating of Platinum with American origin and Powder Blue was with British origins in the union, surprisingly, also descendants in darker blue.

Another option could be, that the different tones are caused by different allele at the same locus. However, in the case is still elusive, in which dominant-recessive ratio are the alleles. This theory would explain, why some American Blue Linien No way darker shades of blue to produce, while some dark lines in the UK constantly come up with lighter rats. Nichole Royer z.B. approved, that brighter rats also occur in the United States in litters of dark blue again. The British breeder Ann Storey bestätgit, that results in two pet rats with bright blue never dark blue offspring.


Bluedark, intensive Variante von Blue
UK (all associations

recessive trait
UK dd
USA gg
Powder bluebrightest variant
UK (Unstandardised)

light variety of blue, Possibly. another allele or Modifier
Slate Bluewie Blue
wie Blue
Sky Bluemedium shade
wie Blue
English Bluewie Blue

wie Blue
American Blueis used to describe various Farböne

UK (unstandardised shades between Powder and standard Blue).
wie Blue
Australian Bluemedium and darker shades
Recently discovered.
unknown, probably as Blue
Russian BlueDark Blue Grayall Verbänge worldrecessive Marlmal
UK rbrb
USA dd

Many thanks to Sabine Presche for the image!