Is size genetic?

[silverbill]

Here's my little girl who's sitting at just over 200g at 4 months old. She's from a mojave/killerbee pairing. The mother is a whopping 3500g, while the father is a more normal size of 1500g. I'm just wondering, should I expect her to be a large adult as well? I'm not sure if ball python size is genetic. She feeds very well and is growing fast so I'm curious.

[Ba11er]

Size in lots of species is hereditary, i don't see why it wouldn't be in snakes. Breeding for size is something more common in larger snakes, to get them to more manageable proportions but large ball pythons could be done in time.

[zina10]

I absolutely believe it is !

If fed appropriately and healthy, a snake will reach its genetically predisposed size. Which can vary for each snake somewhat.

There are variables, though. Over and under feeding can also affect size. If you overfeed a snake, it will not get "bigger" then it should, it will however get "fatter" overall.
With underfeeding a snake can end up "stunted" and skinny.

In the wild, different regions can affect size as well. I used to have some WC Ball Python rescues that were HUGE. Not just huge as in weight, but their heads were much bigger, too, and they were larger yet very fit for their size. (not fat) It has since been established that BP's from the Volta region seem to be larger, genetically.

I bought 5 hatchlings in 2010. None were related. All were fed on the same diet and very conservatively. No power or fast feeding, since I wasn't interested in breeding them. There are 3 females and 2 males. One of the males grew far faster and bigger then any of the others. To the point where I thought he must be sexed wrongly. He grew bigger and faster then the females were. So I sexed him this year and yup, he is definitely male. Just a really big one.

So yes, size is genetically predisposed.

[Stewart_Reptiles]

Heredity plays a part in size, yes however like everything there is no guarantee, all my pieds and most hets from my original female het pied which tips the scale at 4000 grams tend to be 3200 grams and over I have an enchi het pied from 2012 at 4000 grams right now (considering the age it's pretty impressive).

Of course age as to do with size as well they continue to grow throughout their life so seeing large older animals is not unusual and the mother of your offspring could have very well be 3500 grams at 15 years for example.