Feeder Fish without Thiaminase?

[d_virginiana]

As a biologist, I'm well aware that thiaminase isn't a toxin and how nutritional deficiencies work.

However, I'm trying to give practical advice, not debate the molecular workings of thiaminase. The fact is we've had members on here with snakes experiencing severe neurological symptoms after only a few feedings of thiaminase-containing species. Do we know for sure that this was due to thiaminase? No. Were these snakes experiencing known symptoms of B12 deficiency after only a few feedings of a thiaminase-rich species? Yes.
In seeing over four years' worth of posts about potential thiaminase-related symptoms and deaths it really seems that it affects different individuals differently, and seems to have the greatest affect on immature animals. Some people can feed thiaminase-containing species for years with no problems. IMO it is not worth the risk and should not be done just for variety's sake.

As I said, rosy reds are certainly better than the animal starving, but IMO it's plain irresponsible to recommend feeding a species known to contain high levels of thiaminase so long as the rest of the diet contains B12, and even moreso to just recommend that a typical hobbyist try to use a B12 supplement as most people have no way of measuring the vitamin content of their snakes' food or knowing what the appropriate dosage would be. You can overdose on B12, and a B12 shot is a risky procedure for deficient garters even when administered by a vet due to their small size. Also, I'm unaware of any B12 supplement marketed for reptiles or amphibians that is available without a prescription.

Also, I haven't had time to read the papers you linked to earlier, but do they provide comparisons in thiaminase levels between simple cell breakdown due to freezing and what is present in species such as goldfish that produce high levels of it naturally? I would wonder if a low-thiaminase content species would have a comparable amount after freezing to a high-thiaminase content species prior to freezing. My gut feeling is that the content would still be lower in the frozen 'safe species'.

The point here isn't whether or not it would be hypothetically okay for the snake's diet to include rosy reds due to their thiaminase content, but to recommend the safest possible diet to another keeper.

[d_virginiana]

Also all minnows are in the family Cyprinidae so I doubt the "silver ones" are much different then rosy reds. Thanks for the input Ian.

Actually, yellow color has been shown to be linked to thiamine degradation (and by association, thiaminase) in wild fish eggs and fry, and is common in species high in thiaminase. Yes, all members of the carp family can produce thiaminase, but my recommendation to try a silver versus yellow colored species was based off of this, not just pulled out of my rear. If you want the source, I'll provide it later as I don't feel like digging for it right now.
Getting him to take other species of fish within the same family may also make him more willing to transition to new foods including mice.

[joeysgreen]

Lora, then stick to practical advice and not scare tactics. Calling it toxic IMO is as far out as how you think my suggestion of using rosy red's is. If people are smart enough to follow this crazy thread, they are smart enough to make sensible choices with the information provided.

Vitamin B is water soluble so is very unlikely to be overdosed. Nonetheless if someone were to try supplementing and had questions, I'm sure they'd ask; for instance, injecting it into the prey item instead of the snake seems a little safer and more practical.

I do know and respect that you are a biologist; you have mentioned it before. A botanist if I recall correctly?

Ian

[d_virginiana]

Please, show me where I called thiaminase toxic? I called it deadly. Which, if you use the search function, you will see I have ample anecdotal evidence to back up. That isn't a scare tactic, it's a recommendation not to feed something we know can be deadly. I said to avoid rosy reds except as a last resort feeder. That is practical advice. There is a reason we have a 'safe fish' list on this site, and refer people to it when they are looking for feeders rather than telling them to try and balance an unsafe food source with supplements and other foods.

Advising that someone feed a diet so deficient in B12 that it needs to be supplemented with a product that isn't even on the market for reptiles is not practical advice. And if they did ask about how to supplement B12, are you a vet that can tell them the exact amount they should be injecting into a young snake's food to keep it healthy and not overdose? Are you seriously recommending that someone go to a vet, get prescription B12 to inject into feeders, and then try to get the exact amount correct for a very small snake rather than just feeding a known safe species?

[joeysgreen]

No, I recommended that he can safely use rosy reds, which are better then it not eating at all, until he can switch it to something else. If this process takes so long that the owner is concerned about vitamin deficiency, then supplementing is an option. That would be a bridge to be crossed if we get to it.

Ian

[d_virginiana]

Or instead of just trying guppies (which are too small for most adult garters to view as a serious food item) and rosy reds, he could try any species of fish on the safelist. Most garters that will take rosy reds will take other types of whole fish, but trying just guppies and rosy reds is not enough to say 'this snake will only eat rosy reds' IMO.

[guidofatherof5]

I've never seen a species specific fish eating Thamnophis.
If it flips and flops it's Gone!

[AntTheDestroyer]

I guess I got a picky one, he won't even look twice at a guppy, earthworm, or split pinky. I tried to tong feed him the guppy and he was afraid so I put it on a plate, left him all day, and nothing. I don't see the difference in supplementing calcium and b1. Unless you have actual proof that the silver minnows are in fact better, then it might be unwise to suggest one over the other. Not to mention all the shops that sell feeders that I have been to so far only sell guppies, goldfish, or rosies. Denver does not have many bait shops as there is not a lot of water. What other easily available, affordable species do you suggest I try and where is this safe list? Keep in mind that if it does not eat them I wasted a life. I already feel bad enough about the guppies.

[AntTheDestroyer]

Also I would like to be able to breed them in a five gallon tank I already have set up. If they are nice to look at then all the better.

[d_virginiana]

I don't have concrete proof that silver minnows are better than species that produce red/yellow pigment other than thiaminase being associated with the ability to produce those colors (this can be seen in fish, but also species such as silkworms). I do have the anecdotal evidence of having fed my 15 year old garter (average lifespan is somewhere around 8 to 10) nothing but silver minnows for the first ten years of his life with no issues. I stopped once I found this site and realized it was potentially dangerous, but if given the choice between a species of cyprinid that cannot produce red/yellow pigment and one that can, I would choose the one that does not. You are right though, it's difficult to find anything that isn't a goldfish or rosy red in pet stores.

Once they get any size on them at all most garters won't look twice at a guppy. They're just too small for them to really care about. Have you tried silversides? Despite what was said earlier about freezing increasing thiaminase content in cells, there is no scientific or anecdotal evidence showing that this is enough to make f/t silversides a harmful feeder source for snakes, and f/t silversides are generally considered to be a thiaminase-safe feeder. I am not aware of a single thread on this forum where people reported seeing symptoms of B12 deficiency after feeding f/t silversides, and I think it's kind of illogical to recommend live species we KNOW contain thiaminase over a frozen species that does not because of one study that doesn't even put the thiaminase levels in absolute terms.
There have been problems with both fresh and frozen fish from pet and grocery stores that seem to be related to some sort of toxic contamination (that's as concrete of a reason as we can really gather from the info in those threads). These issues are pretty rare, but I'd still try scenting mice to get them used to eating other foods as soon as possible.

Finally, supplementing B12 is different than just supplementing calcium. Calcium substitutes developed for reptiles are available at almost every pet store. I'm unaware of any way of supplementing B12 other than a vet-prescribed injection (someone correct me if I'm wrong) which is usually only done if the animal is already showing neurological symptoms, and can be risky for something as small as a garter.

Also, you can definitely breed guppies in a five gallon tank. Useless as feeders unless you have babies, but neat little animals to have around. I started out with about five guppies I couldn't bear to just flush down the toilet left over after I got two of my babies eating last year, and now I have about fifty.