Thiaminase

[d_virginiana]

I wouldn't say that feeding thiaminase-containing fish is a good idea as part of a 'varied diet'. It's more like something that is okay as a last resort (like a garter that won't eat pre-killed fish and all you can get are rosy reds), or something that isn't fatal if you accidentally give them the wrong type of fish for a couple feedings. Kind of like giving a dog chocolate. It won't kill my dog if he gets to that chocolate-chip cookie I dropped before I can pick it up, but I don't know where the 'threshold' of safety for that is.
It's a risk to the snake's health. They don't benefit at ALL from getting thiaminase-containing fish. If you can provide safe food that they will eat, then do that instead.

And if I lived somewhere that I could find no other food than goldfish or rosies, I would go dig worms out of my yard and supplement calcium.

I know you were just making an example, but unless you are VERY certain of what's in the runoff water that flows through your yard during rainstorms, digging up worms can be bad business for garters as well

[d_virginiana]

They don't benefit at ALL from getting thiaminase-containing fish.

Just to clarify; as opposed to fish that do not contain thiaminase

[Greg'sGarters]

I would recommend for you to try your hardest to stay away from thiaminase based foods. I mean they might come across some in the wild, but just because they eat them in the wild doesn't mean it's good for them.

[thamneil]

Makes sense. Just want to make it clear that I absolutely do NOT feed thiaminase containing fish! Just became curious after looking at water snakes.

[Steveo]

This is a bit off topic but I wanted to share this anecdote.

I've been thinking about getting back into breeding Betta splendens, which was both an old hobby and the subject of my thesis. The idea that groups of immature bettas grow more slowly than smaller groups or individually-housed bettas has been around for decades, always attributed to some unknown growth inhibiting factor excreted or secreted by the largest of the group to maintain their size advantage into adulthood.

Well, it had been a few years since I looked at any of the literature, but some people smarter than me are beginning to suspect that thiaminase is the culprit. The growth inhibition phenomenon has been researched in a few species and one of the common themes is that all species involved produce thiaminase.

[Steveo]

Now I'm wondering if adding thiamin to the water would increase growth rates. Here I am, 5 years out of school and still thinking up new experiments.

[guidofatherof5]

Now I'm wondering if adding thiamin to the water would increase growth rates. Here I am, 5 years out of school and still thinking up new experiments.

I think the effect would be neglishable. I would also be concerned about overdosing. I would think a varied diet would be best.
Just my opinion.

[chris-uk]

Now I'm wondering if adding thiamin to the water would increase growth rates. Here I am, 5 years out of school and still thinking up new experiments.

For the snakes or a batch of bettas?

[Steveo]

The fish. I suppose I should have stated that on a snake forum

[guidofatherof5]

I think the effect would be neglishable. I would also be concerned about overdosing. I would think a varied diet would be best.
Just my opinion.

My comments were snake related.
Sorry, I wasn't following close enough.