New Porcellio scaber color morph

blacksheep998

Arachnosquire
Joined
Dec 8, 2012
Messages
65
So I don't post here much, but you guys really seemed to love my zebra isopods and I'm really excited about this little project I've been working on so I'm going to share it with you.

It was over a year ago that I decided to try crossbreeding my Porcellio scaber 'orange' and 'dalmatian' color morphs.

My orange colony is descended from a wild-caught orange that I found a few years ago, so in breeding them I experimented a bit with the genetics. I found that the orange color is single gene recessive to the wild gray type. Cross an orange and gray and you get what look like all normal wild-type grays, but they're carrying the orange gene. Let that F1 generation inbreed and 1/4 of the F2 generation will be orange.

I suspected that the dalmatian color was caused by a similar mutation of a different gene. But rather than test this by crossing them with a wild gray, I decided to use one of my oranges instead.

My theory was that since both genes are recessive, the F1 generation would be all wild type gray, and then in the F2 generation I'd see a 9 : 3 : 3 : 1 ratio of gray to orange to dalmatian to orange dalmatian. That's a dalmatian isopod with orange spots instead of gray ones.

So I took a baby orange and put it in with some dalmatians and let it grow up there. Luckily she turned out to be female. That wasn't really necessary but did make things a bit simpler, because that way I got to just wait for her to have an egg case and then I could isolate her until they hatched, rather than trying to collect them after they were already crawling about on their own.

She gave me two clutches of offspring, then sadly died. The first clutch was, as I expected, all gray.

p1dJ18g.jpg

The second group of offspring was different. Half of them were gray, but the other half were orange. I'm honestly still not sure what happened there, but I do have a couple ideas.

The first is that there's a male in my dalmatian container who's carrying the orange gene. The second is that some of the orange female's eggs developed parthenogenetically, without being fertilized. I know that Trichorhina tomentosa (dwarf white isopods) normally reproduce this way, but I've never heard of P. scaber doing it.

These unexpected oranges are isolated until I figure out what's going on with them. I should know as soon as they breed.

If their father was just a dalmatian carrying the orange gene then they're all carrying the dalmatian trait and it should reappear in their offspring. If they had no father then they don't have the dalmatian gene and all their offspring will be orange.

But I'm getting sidetracked from the main point.

What I'm excited about is that the first batch of gray isopods started breeding a over a month ago, and some of the F2 generation are starting to get large enough that I can see their colors.

This is a picture I took a couple weeks ago, when they were just starting to show color.

yQU8tHC.jpg

It's a little hard to see, but there's 27 of them there. 15 are turning gray, 5 look to be turning orange, and 7 are white. Assuming that 2 of those whites are going to be orange dalmatians that give me a 15 : 5 : 5 : 2 ratio, which is exactly what I was looking for.

It should also be noted that I didn't try to pick out any particular colors when I was gathering them up. I just collected any I could find.

It's been a little over 2 weeks since that picture, and they're growing nicely. Today though I finally found something that confirmed my original theory!

Check out this beautiful little beast!

20151005_191028.jpg

It's an orange dalmatian! The small black specks are dirt, and the dark line down it's back is of course the guts. I saw a few more that appear to be developing orange spots too, but that was was the largest and the only one I could get to hold still. As an added bonus these guys appear to have red eyes too, though they're still a bit too small for my camera to be able to focus on them well enough to see that.
 

Hisserdude

Arachnoking
Active Member
Joined
Apr 18, 2015
Messages
2,275
Pretty! I do love isopods, and it is nice to see all the new species and morphs that have entered the hobby lately. I have what appears to be a "pied" morph of Cylisticus convexus, and I may isolate them, maybe I can create a pure white morph... Anyway, very nice work, I hope you are able to isolate the Orange Dalmatians! :)
 

blacksheep998

Arachnosquire
Joined
Dec 8, 2012
Messages
65
The orange dalmatians are double homozygous recessive, so they should breed true and isolating them will be no problem.

Also interesting, half of the oranges and half of the regular dalmatians are carriers for the other gene. I'm going to keep them as well and with a little careful culling I should be able to produce a 'rainbow' colony made up of all 4 color morphs living in equilibrium with each other.
 

LittleOddIsopod

Arachnosquire
Joined
Dec 22, 2017
Messages
64
The orange dalmatians are double homozygous recessive, so they should breed true and isolating them will be no problem.

Also interesting, half of the oranges and half of the regular dalmatians are carriers for the other gene. I'm going to keep them as well and with a little careful culling I should be able to produce a 'rainbow' colony made up of all 4 color morphs living in equilibrium with each other.
That’s awesome! There are at least a dozen p. Scaber morphs, it would be awesome to combine them all in one colony to see what whacky morphs show up!
 
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