GigantaBabies?

[Snakesitter]

At Living Gems, we keep very detailed records of weights and growth over time. Accordingly, I have a pretty good idea what babies normally weigh -- according to those records, ranging from a low of 24 grams to a high of 36 grams over the 83 babies for which I have records, with an average of 30.1 and a standard deviation of 2.8.

Last December, Agate surprised me by dropping a litter of only a few very large babies. These “little ones” ranged from 41 grams to 46 grams, with an average of 43.6.

In statistics, “…nearly all values lie within three standard deviations of the mean in a normal distribution” (Wikipedia). All prior experience seems to suggest such a normal distribution, with babies (excluding split-sack twins) falling closely grouped around their average.

These babies, however, weighed *4.8* standard deviations about the norm.

To illustrate this, I pulled two baby drawers: Baby #A-07 from our first litter of the year, and Baby #C-07 from this new litter:



Here they are side by side:



And, in closer shots:




Note they were almost the same size…even though Litter A was 5.5 months old at the time…and Litter C only less than two weeks old.

Even more mysterious, Agate seems to have dropped early. Her POS to delivery time was only 108 days, and the babies visually supported this by their distended bellies, less developed colors, and the fact that one was born with a small unabsorbed yolk sack:



I spoke with several other breeders, none of whom could recall a litter like this. Thus, I’d like to cast a broader net: have any other rainbow breeders seen results like this?

Thank you for reading,

[dbank999]

Very interesting...

..that's about all I can offer. lol

In statistics this would be called an outlier, I believe.

Wonder if this litter will end up averaging on the larger end of adult size range?

You should track the growth of this litter, although perhaps difficult if you sell these animals, but maybe the buyers can be convinced to give you the figures throughout the growth process.

[Kid Boa]

That's impressive Cliff.

[Mr. Bacon]

Interesting indeed, the color difference is striking yet theyre almost identical in size. I suppose its not out of the realm of possibility for any animal to have a later delivery such as occurs in humans.

[Starbuck]

very interesting... i don't know much about the development process of BRBs, but in mammals, depending on the type of placenta (and thus nutrition they are able to get) they are severely limited in their size before parturition, horses rarely have twins because their placenta requires complete contact between maternal and fetal membranes. While i know these snakes rely heavily on their yolk for development, does anyone know if there is any degree of placentation/maternal investment (as seen in some skinks?)?

Was the mother a virgin? It could be that she throws especially large yolk sacs, if not, it would be interesting if you could look at the statistics of clutch size (including slugs) vs average weight of that clutch...


very cool in any case, its really great to see a breeder keep such detailed records!!

[Snakesitter]

Thank you, Derek!

I am planning to carefully track their weights as they grow. I'm not sure if they will end up bigger than normal adults or not, but we will find out!

[Snakesitter]

The credit is all Agate's...I've never seen a Mom look so relieved to be done. ;-)

[Snakesitter]

The color difference is due to age. These snakes do not reach their full color untl 18-30 months old, and the first few sheds make the biggest difference. As these were early, we may even be a shed back before we see their potential....

[Snakesitter]

I've already noticed that the litter's total weight (= baby count * baby weight) was in line with other litters. Still, interesting the way this one went.

No idea about placentation/maternal investment.

The mother was indeed a virgin...or at least a first-time Mom. (She was bred to the same male last year, but nothing came of it that time.)

Good records are key.

Thank you!

[dbank999]

Interesting to say that the litter is in line with others..

So therefore my conclusion would be that the species BRB can produce X amount nutrients to supply the fetus' with. This mother obviously produced a lower number of sacks than the average, no?

We also know that the rate of growth for a snake is dependent on the availability of food and the size of the food item.

If the X amount of nutrient was divided over a smaller sample size of sacks, that means each individual baby obtained more nutrients than say the average litter would.

So with the faster growth rate due to an abundance of nutrients in the sack, could that explain the earlier birthing date, from a result of larger babies at an earlier stage?

Just some food for thought...

[Starbuck]

Originally Posted by dbank999

Interesting to say that the litter is in line with others..

So therefore my conclusion would be that the species BRB can produce X amount nutrients to supply the fetus' with. This mother obviously produced a lower number of sacks than the average, no?

We also know that the rate of growth for a snake is dependent on the availability of food and the size of the food item.

If the X amount of nutrient was divided over a smaller sample size of sacks, that means each individual baby obtained more nutrients than say the average litter would.

So with the faster growth rate due to an abundance of nutrients in the sack, could that explain the earlier birthing date, from a result of larger babies at an earlier stage?

Just some food for thought...

With only one litter i think it is hard to draw any conclusions, but it would be interesting to see this litter compared to other unusually small and large litters. as for the gestation time, from what i know of mammals, they ar e'programmed' to give birth when certain stretch receptors are stimulated, and hormonal signals from the baby. i imagine they just grew larger because there were fewer of them to compete for space, and mom didn't 'kick them out' until those stretch signals were activated. I agree that they could have developed faster (come to term earlier) due to greater quantities of yolk per ovulation.

[KORBIN5895]

Cliff already mentioned that these didn't developed fully and were born premature.

Pm mykee about the odd pos as he had a female royal do something similar.

[Snakesitter]

Actually, this was a slightly smaller litter than average. Our other two litters this year had 20 and 22 babies, respectively; and 15-16 has been touted as a long-term average for the species.

Other breeders have had smaller litters as well -- smaller than this even -- but none recall a result like this. So there is something else going on here.

Excellent logic though!!!

[Snakesitter]

No other small litters of our own to compare to. However, I've purchased babies from other breeders' small litters before, and they were never this big at birth.

Great background on mammal birth, BTW. Good stuff!

[Snakesitter]

Thanks Korbin, appreciated!