Like most things in the rabbit world, there are some basic terms that most breeds use, but there is always room for a breed to pick their own specialized terms, just like you could have a black agouti, chestnut agouti, or a castor--they're all the same color.
I'm sure there are many variables to coats, many unnamed modifiers. As I see it, there are a few basic coat groups. One is for length of coat. According to
Fur Type | rabbit-gentics, the average normal coated rabbit has hair 7/8 to 1-1/2" long, with about 14 hairs per follicle. The guard hairs typically extend beyond the down fibers.
Rex causes plush short coats, with guard hairs the same length or shorter than the down hairs. Rex may have 3-4 times the fiber density per hair follicle, giving the coat that dense, plush feeling. The rex mutation eliminates the longer guard hairs, all of the fibers are of uniform short length, 1/2-7/8" long. The description of the fiber is often 'plush' or 'velvety'. The
angora mutation lengthens the hair to 3-5" long before molting. There are variations on this as well, English Angora has finer and more uniform fiber; French Angora has longer and coarser guard hairs that give Angora yarn the high fuzzy spike. German and Giant Angora (and some of the show lines of English Angora) don't molt, they need to be sheared every three months to keep up with the 1"/month growth rate of the fiber.
There are also straight vs. curly traits. The variations are rex with a curl, the
wavy gene, once raised as a breed called 'Astrex; and a longer haired curled rex version with more angora traits, called 'Opossum Rex'. You can see some of the Astrex photos at
Welcome to Astrex Rabbits There are even recessive genes for
furless rabbits.
Another coat variation would be fiber translucency.
Satin refers to the recessive trait of the fiber to have a thinner, more translucent hair. The light reflects back giving that satin shimmer and sheen.
On top of that, there are several different coat types found, depending on breed. Some, like Rex, have the straight up, dense, plush-feeling coats; here the
hair stands straight up. Other variations are the fly-back and roll-back coats found on 'normal' coated rabbits. When you brush your hand the 'wrong' way up the coat from the rump towards the head, what does the coat do? If it immediately returns to lying flat, it is a
'fly-back' coat. If it takes a while to return, does it slowly over time, it's a '
roll-back' coat. Check your breed's
Standard of Perfection to see what type of coat your rabbits should have. Often, you'll have kits born with the wrong coat type. My husband had to constantly check his Silver Fox kits for this. There's a forum about this,
Fly back? Roll back? Fat back??
According to the
Standard, Rex should have a coat 1/2-7/8" long, with 5/8" considered ideal; straight, upright, dense, springy and even length and texture throughout the coat. Satin is listed as having a coat 7/8 to 1-1/4" long, with 1 to 1-1/8" ideal; hair should have a finer diameter and translucent shimmer, silky, fine, with a very dense undercoat. Guard hairs should extend 1/8" beyond the down fibers. The standard calls for a roll-back coat, and faults a fly-back coat that snaps back into place. (My guess is that the coat the snaps immediately back lacks the extreme density the standard calls for.)
It does sound as if your one rabbit does have more of the Rex traits. It doesn't necessarily mean the kit comes from recently cross-bred stock, there are always a lot of hidden recessive traits that can pop up with the 'right' (or wrong if it's a bad trait for your breed) parent. I've been breeding several generations of black to black rabbits, trying to get a genetically homozygous black breeding pool. I sent one very dark doe to a friend as a gift. She told me yesterday the black doe threw 'polka-dotted' (her words, not sure what pattern she is referring to) kits. I have no idea which buck she was bred to, as the does are in a colony, but there is indeed a booted tricolor harlequin way back in the pedigree of this doe. I've had nothing but self-colored rabbits, no sign of harlequin in several generations of breeding, yet crossed with her buck, up it pops. I'm guessing her fawn buck did the deed, as fawn is recessive to harlequin, and any kits that got the recessive harlequin from mom, would express it. If it was a broken fawn buck, she may have indeed had tricolor harlequin kits. It does raise a concern about my black line though, I thought it was free of the harlequin recessive, but apparently not. I'm probably going to have to start a new black line with different genetics.
I guess this is where you are with your Satins. You see some things that don't seem to meet what you expect from Satin rabbits, like the odd-coat. Now perhaps it simply has even more density than your original rabbits, and it is a good thing. Is the coat perfectly straight, or does it eventually roll back? One thing that the forum link noted, was that different colors seem to have different coat traits. I noticed this when I raised sheep. I had a weird spotted breed called Jacob sheep, white with patches of black. The white always grew longer and crimpier than the black, which was shorter and more wiry, all on the same sheep! They looked quilted when in full coat, so funny. Since you have three blacks, and only one of them is having this 'plush' issue, it isn't due to the color.
At this point, I'd select kits that are closest to the breed standard, ones that are the proper weight/size for their age, have good sheen to the coat, proper roll-back texture, proper coat length. . .and use them as your new breeding stock, and keep breeding towards the
Standard. If the stock that you have is just not genetically capable of being the standard Satins you intended, you may need to pick up a new bloodline of Satins that reflect the traits you are looking for. So sorry that this purchase just didn't live up to its promise, I hope you'll be able to find enough good offspring to breed what you really want.
