Astrex Mouse


One of the main qualities that make mice such great pets is how cute they are, so when you add curls into the equation, their cuteness-quotient flies through the roof. 

Astrex mice stand out among fancy mice for precisely the above reason: you’ll be hard-pressed not to coo at the natural waviness in the Astrex coat, which is a by-product of a gene mutation.

In this article, you’ll learn what makes these cute little critters so unique. Additionally, you’ll find out why they’re renowned among breeders and desired as pets by mouse lovers. 

What Is an Astrex Mouse?

Astrex mice are one of the rarest breeds of curly-coated mice that mouse-lovers keep as pets. The distinguishing feature of these mice is their curly coats and (depending on if they carry the gene) long hair, compared to other mice. For this reason, they’re a variety of fancy mice that tend to be highly sought after for breeding and keeping as pet mice. 

Varieties of Astrex Mice

There are four types of Astrex mice. Each one is categorized based on the length of its hair and the quality of its coat. It’s worth noting that breeders try to meet breeding standards for organizations like the American Fancy Rat & Mouse Association (AFRMA).

Short Hair

The short hair variety of these curly-coated mouse breeds is also the rarest due to how difficult it is to breed them correctly. What makes them challenging to breed is the tendency for the coat to straighten as the mouse ages (around ten weeks of age), to the point where the coat in older mice has completely lost its curls/waves, and only the curliness in their whiskers remain.

The ideal kinds have a short, curly coat, though you’re more likely to come across breeds with short and shaggy hair.

Short Hair Satin

The short hair satin variety is easier to breed to standard than the short hair Astrex because its hollow satin hair curls are easier than non-satin hair. The satin in its name comes from the fact that its coat has a satin sheen or metallic gloss to it due to the “sa” gene. Additionally, you may come across white ones called ivory.

Long Hair

Ideally, you should immediately be able to tell that you’re looking at a long hair Astrex when you see one. The feature that’ll give it away is its dense, long fur. The bucks (males) in this category usually have longer coats than the does (females). 

If a breeder forgoes features like type, size, quality of color, and variety of markings when breeding, they’re more likely to have the desired coat length. 

Long Hair Satin

Out of all the Astrex varieties, these mice are the easiest to breed to the standard. That’s because the hairs that make up their coat are longer and have more space to curl. When you add that their coat has that satin sheen to it, these mice are a sight to behold.

Breeding Astrex Mice

When breeding Astrex mice, it’s best to keep the genetic pool within their own line or a line of mice that have shorter hair, as breeding them this way helps make the coat become curlier generations down the line. As a result, their curly hair should last a little longer as they mature.

In particular, homozygous mice tend to have more curl, especially when young. Also, remember that Astrexes have no fur when they’re still babies, but expect to see their curly hair come in when their eyes open.

What’s Responsible for the Curly Coats on Astrex Mice?

Astrex mice have curly coats due to their genotype. For example, short hair Astrex mice have the Re/* gene, with the scientific name of rex. All Astrex mice have this dominant gene, giving them their distinctive curly coat. 

Additionally, other genotypes combine with the dominant rex gene to make up the different varieties of Astrex mice. For example, mice with satin coats have the genotype of sa/sa as well, which is responsible for their satin sheen, while long-haired mice have the genotype go/go, which makes their hair long.

Why Do Astrex Coats Lose Their Curliness?

When these mice are born, their hair follicles are constricted, making the hair “crinkle” and giving the coat its distinctive curly look. However, as the mouse grows older, its hair follicles enlarge, and thus the curls straighten out. From curliness to straight hair, the whole process usually happens within a few months.

Final Thoughts

Astrex mice are a rare species of fancy mice that are known for the distinctive curliness of their coats. There are four varieties of these cute mice, and each is categorized by the quality and length of its hair.

This fancy mouse is a great pet and best bred within its own line to preserve the curliness in its coat for much longer. That’s because its coat loses its curliness as it gets older.