Inherited factors in Pelvicachromis pulcher

[ed seeley]

Hope the title wasn't too off-putting but I couldn't think of a more succinct thread title!!!

Basically Ste (Ste1200) and I had a little scheme to breed some kribs and improve his Albino fish and work with the Super Red form too. Unfortunately our plan has hit a little road bump as the female Super Red has died. However I have a male that is colouring up nicely despite a bit of a death wish (he's already been into the filter and been mixing it a pair of Wild scalare!!!).

My question is how is the extra red colouration of the Super Red strain inherited? Has anyone bred this strain or tried crossing it with another strain? If it's a dominant/recessive feature (which I don't think it will be, but I'm hoping...) then I can simply cross it to another nice spotty strain and then cross the F1 to get the extra red back. Otherwise it's going to be a more tortured affair I know!

Also the albino strain Ste is working with (I hope he'll add his experiences and maybe even some of his excellent photos here) seems to throw up a few interesting results suggesting it's not a straightforward albino with a single gene locus. Has anyone any experience of that and any unusual observation too?

I'm hoping we might be able to get a better idea of how the genetics work of the three factors I want in a krib strain. I'm looking whether we can cross Super Red with albino to get a white krib with a much stronger red colouration. I'm also hoping that we can breed more spots back into the Red strain and the albino strain too. I think a red, very spotty albino krib would look amazing!

 

[apisto-nut]

dont mean to high jack your thread But....

I would like too know this also as I have young from a super red male .

the male was breed to a colorful normal female and I would like to increase the red in further generations .

What would the best plan be to accomplish this ?

1 . breed a young male back to the mother
2 . breed siblings together
3 . ????????

any help would be great

 

[tjudy]

I love this topic...

Every physical feature is heritable. Some specific traits are controlled by the presence or absence of a single gene. What we see as the finished product as a fish is the collection and interaction of all the traits. In some cases the expression of a trait will mask another, while in other the expression of a trait will enhance another.

Color expression in general... there are cells in the skin that control the color of a fish. Pelvicachromis are highly variable in the number and type of color cells (chromatophores). Different types of color cells have different names, but the basics are

• color cells (different cells for different pigment induced color... usually yellow, green, brown, sometimes red (more on red in a moment), orange and others)
• iridiophores - cells that control a pigment that causes irridescence
• melanophores - cells that specifically control the expression of black pigment

Some traits have an affect across the entire body of the fish, such as albinism, amelanism, melanism or leusticism (is that a word?), all of which affect the expression of the black and/or color pigments throughout the fish in some way.

Other traits may only affect the expression of one specific part of the body. Such as the genes that control the type of black mark in the caudal peduncle of a platy... 'mickey mouse', crescent or none. Or, specific to Pelvicachromis, the number and size of caudal ocelli in males.

When we are dealing with inheritance of color traits in non-albino/amelanistic/leusistic (whatever it really is) kribs, the problem is that there are too many different chromatophores. It would be very difficult to concentrate of selecting fish for red bellies and not also end up affecting the number and size of ocelli. What most of us do is picture the perfect krib in our minds and pick the males that most closely resemble that phenotype out of every generation.

In order to enhance the phenotype faster the best thing is to breed offspring back to parent or at least sibling to sibling. Why? If the genes are present in the offspring, then they have to be present in the parent. If the pheotype is recessive, then breeding a recessive offspring to its parent increases the ratio of recessives that will appear in the next generation.

Red in kribs.... there are two things that control red. The red edges of fins are controlled by chromatophores with red pigment. That may also be true to some extent for the belly (especially in males), but that area of the body is also flushed red with blood flow near the surface of the skin... especially in females. Choosing a female because its belly gets really red when courting may not result in an enhancement of red on the abdomen of males.

A few observations of mine associated with tank strain kribs:

The 'super red' strain of kribs is highly variable even within a group of siblings. What we need to do is sell fish based upon their individual phenotype... not the phenotype of their parent. Just because a krib had a super red dad does not mean it will be super red. Grow them out. If they are super red then they can be sold as super red. I have been shown fish that are supposed to be super red, but even when they are all lit up the fish is not any more red than an average tank-strain male krib. Here is a good example. BEAUTIFUL krib... but is there enough red to be considered super red? The super reds I have had that I think of as super red NEVER lose their red unless they are very stressed. This male is the king of his tank:

This fish is super ocellated and very blue. I definitely came from a strain of fish that throws red males (I have seen others from the same strain that are very red, and the owner of this fish generaously gave me some fry that I hope will look like this male... and a red one or two would be a bonus.)

There are more than one 'white' phenotypes in kribs. I have not been able to figure them all out yet. The most common is usually called 'albino', but that may not be the correct term. (I think I will spend some time today researching this.) This most common gene is a DOMINANT gene and results in the absence of all pigments from the body and eyes. Interestingly the irridiophores still express, though without the supporting color. That is why the fish still shine. The masking of melanin is complete with a single dose of the gene, but the masking of other colors is only partial. That is why there are 'albino' kribs with color. A double-dose of the 'albino' gene results in a lot less color, possibly none at all, because there is no 'wildtype' gene to express the colors. HOWEVER, these double dominnat 'albinos' are very rare, frequently unhealthy and rarely breed successfully.

If you breed two albino kribs together and get 100% albinos, but small spawns (less than 30 or so), then at least one of the parents is probably double dominant. If two albinos produce medium spawns (50 or so) of which 1/3 are not white, then both of the parents are heterozygous. You would expect 75% white to 25% not white, but the homozygous white offspring (25% of the total) are dieing early. By crossing a heterozygote white to a non white you will get 50/50 in the spawn, a normal size spawn and all the 'albino' will be healthy, colorful heterozygotes.

I have never seen a male 'albino' krib with any appreciable red in the abdomen, which leads me to think that red in the abdomen of males is caused by chromatophores. Albino females that spawn get very red bellies, however, so I think that color has more to do with blood flow.

Ste... PLEASE PLEASE PLEASE post images of your intersting 'albinos'. I have seen one or two leucistic kribs (white with a black or blue eye). Got any of those?

 

[ed seeley]

dont mean to high jack your thread But....

I would like too know this also as I have young from a super red male .

the male was breed to a colorful normal female and I would like to increase the red in further generations .

What would the best plan be to accomplish this ?

1 . breed a young male back to the mother
2 . breed siblings together
3 . ????????

any help would be great

Hijack away mate - all info is good info!

Can I ask you how red are the young?

Personally I'd try mating an F1 female back to dad if he's the Super Red one. Failing that I'd breed with the two most colourful siblings.

 

[ed seeley]

Cheers for all that Info Ted. I'll take a photo of my little Super Red male. He seems to colouring up nicely to me and I think I'm going to mate him with one of Ste's Albino offspring.

As they aren't true colourless albinos (well as far as I'd call them that anyway) I'm hoping we can add some red colouration by the cross. The spots will take more work unless I can find a gorgeous spotty male like the one you pictured to throw into the mix!!!! I'm gonna need more tanks... :biggrin:

 

[georgedv]

I wish I could help more. The only thing I can present here is my experience on breeeding a female albino krib and a regular male. I got about 30 fry that survived and they are all white. I will check them tonight to see if their eyes are pink like their mothers or another color.

I started a thread 2-10-08 on another topic ("Are These Apistos") and a picture of the female slipped in. Check her out there.

So far the fry (3 months old) show no coloration....just attitude! They are lively, aggressive and healthy.

In the next few weeks I am going to try for another spawn with this pair just to see if the results stay the same.

g

 

[tjudy]

George... The female you bred to produce 100% albino fry is most likely a double dominant fish. P. pulcher spawns are usually much larger, so I suspect that the low number of fry is due to the females relative low fitness compared to heterozygote or wildtype females.

I was digging a bit today and found several references to 'dominant albimism' in many creatures. With kribs, and other animals, the relationship is pretty much considered to be one of incomplete dominance where a single dose is less white than a double dose. THis is true in P. pulcher. In horses this is called the 'creme' gene.

In trout an incomplete dominance has been discovered that also affects eyesight, with a double dose of albinism gene imparting blindness and a higher frequency of cancer in the eye. Interestingly there is a very similar gene that affects humans, and the trout are used to stidy that disorder. I have not seen any indication of problems with vision in albino kribs, so I do nto think that this is the same gene.

 

[georgedv]

I do not know how relevent this is. This is the females first spawn. When I counted I quit after 50 because I was not sure if i was counting some fry twice.

When she spawns again I will take a more carefull count.

Ed, I like this thread...here is where you learn things where text books make them complicated.


g

 

[ste12000]

Morning chaps, Interesting thread Ed, Ted....im good at keeping/breeding dwarfs but the whole genetic thing usually tends to go straight over my head, ill supply the pictures and experiences of my fish and then learn a bit about genetics from you guys..
Firstly i must say i dont own the pair pictured below anymore, my fishroom only holds 35 tanks, 10 of which are breeding tanks the rest are growout...as you can imagine there is a rotation policy so i can breed new species...The kribs were spawned twice before making way for a pair of A.elizabethae. I do however still have juveniles of both the albino and normal coloured fry so plenty of fish for you to work on Ed...
The albino juveniles are currently stalled at around an inch? the normal coloured are almost half grown and showing the most stunning reds and yellow colours iv seen in a long time! they dont show a red stomach ie Super red, i mean the colour on the top of the dorsal and caudal fins, The slower growth of the albinos is likely to be linked to the coller temps over winter, the bottom rack of tanks has been sat at 74f for a good few weeks now while the normal fish are on the top shelf at 80-84f..
The adult albino kribs were bought as adults from a local guy, he also gave me a bag of fry so i was already aware they had split broods, obviously being Pulcher they were not difficult to spawn so i bred them almost immediatly, broods were split 70-30 in favour of albino in the first brood and then 50-50 in the second..
The albino? parents were not true albino as far as i can tell!!The male showed yellow and a washed out red/blue while the female showed pink pelvic fins and the red stomach..i was under the impression that abinos showed a complete lack of colour?? Pics are below so you can see for yourself..

 

[ed seeley]

Cracking pics as usual mate! And gorgeous fish. We'll have to sort getting some down to me once the weather improves as I have a clear 2ft tank they could go into.

George is there any way you can try spawning the offspring of that pair? It seems to me you must have two homozygous fish; the female with two 'albino' genes (nn), the male with two 'normal' genes (NN). All your offspring then should be heterozygous (Nn) albinos and if you cross them you should get roughly 25% normal coloured fish (NN), 50% heterozygous albinos (Nn) (which should be more coloured) and 25% homozygous albino (nn) like the mother. This would prove the co-dominance of the gene!

I reckon my way to go is going to be to cross as colourful as possible female albino with my lone Super Red male. This should give me 50:50 albino and normal (assuming the colourful female albino is heterozygous). In that brood I can then select for colour in the belly of both types and if I find some nice red fish cross those back with the original male or each other. I might be able to set up my own normal red strain as well as getting a good albino strain. The thing is I imagine only the heterozygous albinos will ever show any extra colouration - if any do!

 

[ste12000]

Thanks Ed, ive just been out looking at the normal coloured offspring, ive got someone picking most of them up on sunday to clear the tank but i will go through them very carefully to pick out my future breeders...I have one male out of 50+ that is showing signs of a red stomach, several have a few ocellii but nothing like the amount that Teds stunning picture shows..By the way Ted that fish is my definition of the perfect Krib! Stunning!!..
In most other respects under proper lighting some of my adult males will look similar to Teds pic..
It will be interesting to breed brother to sister of the normal strain to see if the albino gene is still present and in what ratio...also interesting will be the oppurtunity to breed brother and sister in the albinos to see the results there!
After you first suggested it i completely forgot about this project hence moving on the adults, its now caught my attention again and im looking forward to learning(both first hand and from you guys) about linebreeding!!

 

[ed seeley]

Well it nearly didn't when I thought I'd lost the Super Reds!!!! I'm going to have to keep my eyes peeled to see if any of the LFSs have some heavily spotted kribs I think, but perhaps it's best to work on getting the red colouration sorted first! You never know some spottier individuals might crop up after crossing with your albino strain. After all the less new lines we introduce the less other factors we'll have to select out later!

 

[jmtrops]

I had a long reply and lost it before I could post it so here is the short version. It took me 5 - 6 years to get to this point. I will try to post the pic but you can see it on my web site www.jmtrops.com under "West African Cichlids"

Jim

 

[apisto-nut]

This is the best shot I could get of one of the male juvies , he
keeps this red colration all the time and it intensifies when his
mom comes around .

 

[tjudy]

l your offspring then should be heterozygous (Nn) albinos and if you cross them you should get roughly 25% normal coloured fish (NN), 50% heterozygous albinos (Nn) (which should be more coloured) and 25% homozygous albino (nn) like the mother. This would prove the co-dominance of the gene!

This statement is partially true. I am going to change your symbols a bit to better illustrate the genetics here. This is a codominant gene, meaning that in the heterozygous genotype the fish will express a phenotype different that either homozygous genotype. So instead of 'N' and 'n', let's use '+' to indicate wildtype (this is a normal symbol for wild type in genetics) and A for albino. Here are the possible genotypes and phenotype specific to this gene:

• ++ - wild type (not white)
• A+ - white krib that expresses no black pigment, but will express other pigments
• AA - white krib that will express very little color pigment at all; this genotype is semi-lethal, meaning that it imparts a decreased fitness. When competing with other fry they grow very slowly. When they do survive thye are frequently stunted in growth. If they reach adult age they are hard to successfully spawn and produce (females any way) small clutches.

Here are the common crosses and what you would expect to get in the offspring.

• ++ x ++ : 100% wildtype (not white) offspring

• ++ x A+ : 50% ++ wildtype & 50% A+ white offspring. This cross, in my opinion, produces the healthiest and chance for the prettiest albino fish.

• ++ x AA : 100% A+ white fish, but because the albino parent is AA the spawns are infrequent and often small.

• A+ x A+ : The EXPECTATION is 25% ++, 50% A+ & 25% AA. However, because the AA fry are less fit they usually die. So end result of a month of rearing is usaully 33% ++ & 66% A+ (+/- 1%).

• A+ x AA : 50% A+ & 50% AA. Here you are doubling up the difficulty with the AA genotype. First, the AA parent is less fit, spawns infrequently and has small spawns. Second, 50% of the fry that are born are less fit and likely to die.

Albino or amelanistic gene? This is hard to determine, and I have not seen a difinative answer to the question. Based upon my experience with corn snakes, in which the difference is very clear, I side with the idea that the gene is more amelanistic than albino, because even with the AA genotype there is usually some color pigment expressed (though very little).

 

[georgedv]

Ed, I will breed the siblings and see what comes out once they are of age.

By the way all the pics in this thread are incredible.

g

 

[ed seeley]

I look forward to seeing the results George! I'm certainly iching now to see whether we can transfer some of the extra red colouration across to the heterozygous fish. If not maybe we'll just succeed in producing a better, well spotted red form, who knows?!

Apisto-nut my young male 'Super Red' is certainly darker than that, but I don't know if I'd say he was redder (but I am colour blind!!!). He's also got a fair bit of growing still to do as he's barely an inch long. I like the red head and gill cover on yours.

Ted that's true about mortality and I forgot about that factor. I agree this mutation is certainly not a standard albino and maybe leucistic or amelanistic would be a better term. As long as it's not xanthic and we can't get any red pigments!!!! :wink:

 

[jmtrops]

Another try at posting a pic.

Jim

This is what I have after 6 years of work.

 

[ed seeley]

I had a look at your site Jim and was intrigued by your reference to two forms of red pulcher. Were they the domestic one and the wild collected Nigeria one? Have you tried using the wild strain in breeding the domestic one?

 

[jmtrops]

I have not used the wild form for this. That form I got from Ted and there was no real location but it is not like the one posted on this thread as they don't get the red up into the face and only have it in the belly. I used the strain like the one posted to try to get the red all the way to the face in the albino like the pic I posted. I have a group of fry from that male and I have to see what they turn out like.

Jim