Is this beautiful kit chinchilla? Ghost chinchilla? Something else?

[ingers]

I hope there's room in your lives for another rabbit coat color question! It comes with cute photos.
Seven kits were born on the 12th of February to a sire where I have four generation pedigrees and a dam where I have... a few anecdotes about her line. They are part of my "mini-angora" project to develop more pet-sized, clean-faced, fiber animals.

Genetics I know about:
The sire is (or appears) self-black. He carries chocolate and non-extension. I thought he was aaBbCCD?Ee. Now I'm not so sure about the C genes. This is a baby photo, but conveys the coloring. His eyes are a nice deep, clean brown. No marbling. He was pure black as a newborn.



I'm not really interested in the exotic c genes, and I had assumed you have to try hard and pay extra to get shaded/chinchilla to show up. But assumptions and recessive genes are funny stuff, aren't they?

I see that both his dam and his sire each have one REW great-grandparent and one chinchilla great-grandparent.

The dam (Charlotte) is a chocolate agouti Rex/French Angora mix. She's the one in my profile photo.



Her dam is Rex x French Angora and was described "silver-tipped chocolate." I don't know exactly what that is genetically (other than chocolate), but several of Charlotte's kits appear tipped or ticked. I don't have a photo of Charlotte's mom.

Her dad is (I think) a very red-tinged chocolate agouti. Here he is:

I know that there is chinchilla in Charlotte's line, and a cousin or half-sibling is a silver marten. This breeding was in part to figure out Charlotte's A gene - does she carry self, otter, or is she AA? The answer there is clearly otter.


Here's the main kit in question. I think she's beautiful. Is this chinchilla? She appears exclusively black and white. I see no red/yellow color on her at all. It just seems more white-dominant than other chinchilla rabbits I've seen photos of.




Since I have space for one more photo, is there a name for this ticking on an otter? In person, it does look "gold" as opposed to silver.

 

[Alaska Satin]

Genetics I know about:
The sire is (or appears) self-black. He carries chocolate and non-extension. I thought he was aaBbCCD?Ee. Now I'm not so sure about the C genes. This is a baby photo, but conveys the coloring. His eyes are a nice deep, clean brown. No marbling. He was pure black as a newborn.

View attachment 45522

I'm not really interested in the exotic c genes, and I had assumed you have to try hard and pay extra to get shaded/chinchilla to show up. But assumptions and recessive genes are funny stuff, aren't they?

He could either be a self black <aaBbC_D_Ee> or a self chinchilla <aaBbC_D_Ee>. And no, you don't necessarily have to try hard to get shaded <c(chl)> or chinchilla <c(chd)> to show up. Both of those can (and did, in my barn) lurk undetected for along time, only popping out when the carrier rabbit was bred with the "right" mate. Given the chinchilla kits he produced, it's certainly possible that he is self chin.

Her dad is (I think) a very red-tinged chocolate agouti. Here he is:View attachment 45519 View attachment 45520

That buck looks like it may be a harlequinized castor or possibly harlequinized amber (aka chocolate agouti); note the variegation in the body color, the partial ear lacing, and especially the light side (his right) under his nose versus the orange side with a darker spot (his left):

In the full photo, the partial ear lacing looks black on my screen. If he has black anywhere at all, he's not a chocolate agouti; the harlequinization could be resulting in the lighter ticking which suggests chocolate agouti. But you'd have to look at the rabbit in person to decide whether he is black-based or chocolate-based; ear lacing is often the first place I check.

Since I have space for one more photo, is there a name for this ticking on an otter? In person, it does look "gold" as opposed to silver.

View attachment 45530

In otters it's just called "ticking" in the SOP (Mini Satin, Satin, English Lop, French Lop) or "orange tipped guard hairs" (Holland Lop, though the hairs are all orange, not actually orange-tipped).

Here's the main kit in question. I think she's beautiful. Is this chinchilla? She appears exclusively black and white. I see no red/yellow color on her at all. It just seems more white-dominant than other chinchilla rabbits I've seen photos of.

View attachment 45525
View attachment 45526View attachment 45527View attachment 45529

Yes, she looks chinchilla. There can be a lot of variation in the heaviness of the ticking in chins, but another possibility is that there's wideband <ww> influence here. Wideband alleles extend the width of the intermediate ring (in chins, that's the pearl ring), and sometimes also increase the extent of the agouti "trim" on the belly, inner legs, around the eyes and jawline, etc. The overall effect is to make the surface color of the rabbit appear lighter relative to a typical chinchilla (or chestnut, as the case may be).

 

[ingers]

@Alaska Satin thank you! Does c(chd)c(chd) look different than c(chd)c? It's possible that Charlotte is contributing the c(chd) and the sire is Cc, right? I don't know of any REW in Charlotte's line (doesn't guarantee it's not there, of course.) Or is it only c(chl) where the partner c gene matters? (Seal vs. sable)

I was thinking there might be a wide band influence on the chinchilla too. Does that also affect the coloration on otters? We have other otters (adults) but none with the level of orange extra in the ears, snout, chin, and tummy lines that the black otter kit seems to have. I think the orange is on the chocolate otters too, but it's less apparent.

 

[Alaska Satin]

@Alaska Satin thank you! Does c(chd)c(chd) look different than c(chd)c? It's possible that Charlotte is contributing the c(chd) and the sire is Cc, right? I don't know of any REW in Charlotte's line (doesn't guarantee it's not there, of course.) Or is it only c(chl) where the partner c gene matters? (Seal vs. sable)

In my experience, a rabbit with homozygous chinchilla <c(chd)c(chd)> alleles doesn't look different than one heterozygous for chin and REW <c(chd)c> or chin and himalayan <c(chd)c(h)>, but of course that may not be true in every case. @reh may have some more information about that on the excellent color page http://rabbitcolors.info/. I have only had a few rabbits that I knew to be homozygous for chinchilla, and I would not have been able to tell them visually from their heterozygous chinchilla relatives. So yes, from everything you've posted, it seems to me that either Charlotte or the buck, or both could be contributing a chin allele.

I was thinking there might be a wide band influence on the chinchilla too. Does that also affect the coloration on otters? We have other otters (adults) but none with the level of orange extra in the ears, snout, chin, and tummy lines that the black otter kit seems to have. I think the orange is on the chocolate otters too, but it's less apparent.

View attachment 45547View attachment 45548View attachment 45549

That's a very pretty bunny! I l-o-v-e black otters!

I don't know if wideband alleles would affect color or pattern expression on otters or not. In my experience, the intensity of the tan on an otter is strongly related to modifiers called rufus factors. (Several times, I have used a good red Satin, rufus factor ++++, bred to one of my otters to intensify the tan markings in the otters). The wideband alleles increase the width of the orange intermediate ring, so the orange coloration on the otter "trim" might take up more of each hair - on an otter, the orange trim is only orange with a light base and sometimes a faintly lighter tip- there's no ring color, but there's no dark tipping on the hairs, either. It's an interesting question.

What I have noticed is that otters which are homozygous for tan <a(t)a(t)> usually seem to have better/more extensive tan markings than those heterozgous for tan and self <a(t)a>. The heterozygous individuals have much-reduced or sometimes absent eye rings, and more minimal markings elsewhere.

The tan on chocolate otters is quite often less apparent than on black otters, due to the lower contrast between the chocolate and orange hues. This very richly-colored chocolate otter Satin, for instance, had wonderful tan factor (yes, he had a red progenitor). You can even see it quite distinctly along his belly; but it's still not as striking and highly-contrasted as a good black otter's tan.

 

[ingers]

I see what you mean about the lower contrast in the chocolate otter, but that's a very pretty rabbit! I can see the satin sheen even in the photo.

@reh - the rabbit colors website is very cool! I had not seen it before. I am stuck on the fictional photo of the satin-angora-rex and I want it to exist. Maybe that's my next project... (Charlotte is a long-haired rex carrier, so it's not a million miles/generations away.)

 

[ingers]

Wait a minute, what's up with my "self-black" rabbit? Is he breaking all the rules? The fact that he had a chinchilla kit was interesting and got me wondering if he carries chinchilla or is a self-chin. (As in, for him, aaBbc(chd)_D_Ee, but where that second c allele would have to be c(chd), c(chl), or c.)

But stop the presses, he seems to have an ORANGE chin. What the heck. Maybe I'm just seeing things, but once I started looking closely, I have seen it multiple times in different light.

It's subtle, but... what is it? Just a weird mis-mark? If he has orange, he's less likely to be self-chin, right? Since the chinchilla would repress the orange? The photo below is just for context. He's a nice boy. Good size and good fur.

 

[MsTemeraire]

But stop the presses, he seems to have an ORANGE chin. What the heck. Maybe I'm just seeing things, but once I started looking closely, I have seen it multiple times in different light.

He's just 'rusty' there, the fur has lost some pigment, most likely because of his scent glands under the chin.

 

[Alaska Satin]

Wait a minute, what's up with my "self-black" rabbit? Is he breaking all the rules? The fact that he had a chinchilla kit was interesting and got me wondering if he carries chinchilla or is a self-chin. (As in, for him, aaBbc(chd)_D_Ee, but where that second c allele would have to be c(chd), c(chl), or c.)

But stop the presses, he seems to have an ORANGE chin. What the heck. Maybe I'm just seeing things, but once I started looking closely, I have seen it multiple times in different light.

It's subtle, but... what is it? Just a weird mis-mark? If he has orange, he's less likely to be self-chin, right? Since the chinchilla would repress the orange? The photo below is just for context. He's a nice boy. Good size and good fur.

I've seen stains that color on self blacks (and self chinchillas, and blues); some rabbits get stains there from marking (there's an oil gland on the chin). If this is the only place where there is different color, I'd be inclined to call him self.

Chinchillas don't always have all of the tan coloration suppressed: there are such things as "rusty" chinchillas (that are not sable chins, though I have my suspicions about a recessive sable allele possibly affecting chinchilla coloration). Many chinchillas have rusty coloration as kits, and some of them occasionally retain a bit of rustiness into their adult coats, but that tends to be across the back. I'd still be comfortable calling him a self black or a self chin.

 

[ingers]

Thank you @MsTemeraire and @Alaska Satin! Just rusty, and rusty can happen even on chinchillas sometimes, got it. That makes sense and it's reassuring. I'd rather he not break all the rules! He's still young (7 months) and chin-rubs everything, all the time.

Yes, the rest of his fur runs the full spectrum from white to black, but just in the way that happens on angoras (he's not broken-color).

I'm still learning and when he was younger I got concerned I'd mis-identified him as it looked like rings in his fur . But it's not agouti, that's just different gradients of the same black-to-white color.

 

[reh]

Table from Robinsons, Genetics of the Rabbit, mostly based on work of Sawin and Nachtsheim.
The use of chinchilla alleles hase changed.

A – a d – a chi – a m – a n – a Nachtsheim
C – c ch3 – c ch2 – c ch1 – c H – c Sawin

C – c chd – c chm – c chl – c h – c Robinson

Nachtsheim later omitted a d, Robinson omitted c chm.