Post by studentfrombc on Nov 28, 2006 14:18:39 GMT -5
I just wanted to start another quick thread about another snake trait. I have heard that some corn snakes are born with a kink in their tails. Is that a trait that is genetic, or is it just a congenital defect, and will the snakes grow out of it? I have a picture of a motley snow with a kink in its tail as an example. It isn't much of a kink, but I was wondering what is the prognosis for this snake, breeding-wise. Is the kink in the tail due to excessive inbreeding? I assume a snake would have to be heavily inbred to get a motley snow (which I have learned is a combination of three recessive genes).
Ok now I just have to figure out how to insert the picture ???. Help?
As for the kinked tail...I have heard some people say that it is due to incubation problems, while others say that it's due to inbreeding...I could easily see both causing deformities, but I don't really know...
Either way, I would personally stay away from a kink tailed as a breeder, but maybe there isn't really a good reason for that....Maybe someone else knows the REAL cause??
Kinks in the tail are minor and could result from trama too - unless it is seen to have the kink when it hatched. I would think of trauma as the most likely cause - pinched in a cage door or lid when very young and not related to inbreeding or incubation - though either could possibly be a cause.
Kinks along the body are more significant as they can interfere with digestion and internal function and these can be a result of temperature spikes during incubation. Snakes can survive, often with very severe kinks - we had a Mexican black kingsnake that we got as a rescue that was severely kinked and did not have any health problems.
Inbreeding is not uncommon in the reptile hobby as people strive to get new recessive mutations produced as quickly as possible. The case has been made that it takes more generations of close inbreeding to see the depressive effects in reptiles than mammals. If you have a snake that is triple homozygous for some of the more uncomon genes, it is certainly possible that it is highly inbred. With a snow motley, those genes are well established and quite widespread in the corn population, though the motley is less common, so it is possible that a snow motley could result from an outcross. Best to contact the breeder to see if you can get more details on the background of yours,
Last Edit: Nov 29, 2006 14:29:33 GMT -5 by vanderkm
Post by Shawn(snakebite) on Nov 30, 2006 19:20:23 GMT -5
In my opinion a kinked tail is minor and should have no effect on the vigor of your corn.I know incubation temps , especially drastic spikes in temp can cause kinks and this is very common in the Indigo snakes , that I've heard. In all my breeding ventures I have not had a baby with a kinked tail....yet? I am guessing it was due to some physical trauma , yet I do believe that heavy inbreeding can cause weakness in certain areas of a corns physical developement.
This is interesting...that both of you consider a kinked tail minor...even though you acknowledge that it could be genetic or incubation problems...(I agree that a kink from an injury would be inconsequential). I understand that it is less serious for the snake than a body kink, but I still think that the animal should not be bred...
IF there is a possibility that this is a heritable defect - why risk passing it on by breeding? Also, IF it is a congenital defect from incubation problems - why risk that there isn't something else wrong too?
Maybe I adhere too strictly to my dog/livestock thinking of "only bred the best to the best"...I just don't see why you wouldn't pass up breeding a kinked snake, and search for a "perfect" one instead...it's not like corns are rare or anything...
Also, maybe my mind has been tainted by our one experience breeding a kinked snake. She was a large, beautiful reverse okeetee, and she double clutched for us her second year of breeding...she refused to eat after the first clutch, and lost piles of condition. It was only after she lost piles of weight that her two body kinks became apparent...and one of the babies in that second clutch had a kinked tail - the first and only kinked baby we ever had...
Do you guys have any experiences breeding kinked (not from injury) snakes that had good results?
Kaley - I guess I wouldn't say that I would never breed a snake with kinks - but I would be very unlikely to - I tend to select breeding stock based on a series of criteria and not many of them are 'all or none' they are mostly gradations toward what I consider best. I have used less than ideal individuals in the past (one corn I have has abnormally shaped ventral scales - a minor defect but something I am not crazy about) when I plan to select strongly against that characteristic in the line and I need other genes that snake may offer - so I guess I would never say never. But I agree - I would look for an alternate if I could. Even though corns are common, some of those with the less common genes are hard to get and expensive, so sometimes you take the bad with the good and use stiff selection through several generations to pay the price.
I have only owned two kinked snakes - one a rescue mexican black where the kinks were presumed due to trauma but could have been from incubation - and one corn that was a kinked hatchling I got in a group of non-feeders so I could practice getting snakes to feed. It had a very distinctive, short, thick bodied look that is very similar to the motley snow in the photo. I wonder if there may be some association between the visible kink and some underlying problem even though the only visible kink is in the tail. I did not like the body shape (short and thick) on the guy I had and he was placed in a pet home once I got him feeding. I would be cautious about breeding a snake like the one pictured - other issue is that if it is a male the kink is in the tail where the hemipenes are located and there may be some interference with function.
Actually Kaley I am a big believer in the importance of selection pressure. In most discussions of breeding it is all about what the genes are and how you can get the right combinations of recessives and I think there isn't nearly enough attention paid to how important it is to apply selection pressure in order to make progress in a breeding program. For so many people it tends to be about breeding to produce the morph and then keeping them all back to create more of that morph.
I still have trouble deciding on what features to use in setting priorities for selection of offspring and I change my mind about criteria too often I think, but I believe it is important to emphasise that selection pressure has as big an impact on future generations as the genetic potential from a breeding.
Post by Shawn(snakebite) on Dec 14, 2006 0:08:29 GMT -5
I agree that alot of breeders have the mentality of just pumping out the numbers and not putting in the quality. I know for myself as of next year I am putting my efforts into specific projects and am going to produce less of the usual types of snakes such as your basic corn morphs.I usually produce around 200 babies each year varying a bit each year, and they are quality animals, and no where near the numbers of larger breeders.I am probably going to have a smaller % of hatchlings next year , but what I do produce will be of a good variety and hopefully have some very unique stuff if all goes well and if not , at least it won't be just for the fact of pumping out numbers of common things , just because I can.Sorry , got a little off trail there, but what I was saying is that it's great to find a breeder that has a specialty or breeds in small numbers , because it usually means they are really fond of that particular specie and put alot of attention into it.