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.
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.
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!
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.
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.
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.
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!
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.
