Feeder Fish without Thiaminase?

[guidofatherof5]

With live or freshly killed fish thiaminase is not a problem. The above posters have discussed other issues regarding using fish as prey.

What?

[joeysgreen]

Coincidentally, I found out while researching this topic that thiaminase is used in cancer therapy. Who knew?

This first one is a lame reference for this topic, but mentions that some fish have more thiaminase than others, and that feeding frozen fish of any species is more problematic than raw.
Wilkinson, Stacey Leonatti. "Reptile Wellness Management." Veterinary Clinics of North America: Exotic Animal Practice 18.2 (2015): 281-304.

This reference is an example of a specific fish species that can cause vitamin B1 deficiency when fed to alligators. With reference to wild populations I "assume" they are talking about feeding fresh raw fish and not frozen.
Ross, J. Perran, et al. "Gizzard shad thiaminase activity and its effect on the thiamine status of captive American alligators Alligator mississippiensis." Journal of aquatic animal health 21.4 (2009): 239-248.

This reference states that certain fish, namely those related to herring or smelt (potentially ignoring fish species not used in aquatic bird management) are richer in thiaminases than other species. It also refers, and this perhaps refines my understanding of the issue, is that there are certain bacteria that produce thiaminase (which concurrs with my literature search but I previously thought was an unrelated tangent). How this relates to fish is that fish goes rancid very quickly, and even in the freezer (one paper recommended -18C storage and even then there was progressive increase in thiaminase), thus this bacteria produces thiaminase very quickly. To further the problem, fat soluble vitamins (like vitamin E) are destroyed very fast as the fish breaks down which adds another nutritional deficiency to the problem.

Pokras, Mark A. "Captive management of aquatic birds." AAV Today (1988): 24-33.

...

So in the end, I'll be completely up front and say that I ignored one issue by attending another. Some fish do have enough thiamine to cause problems. Are rosy red minnows and goldfish these species? Likely... I've seen more information on the goldfish than the minnows but none that has come from the primary literature.

My original point should not be lost however as it is equally valid. Any fresh fish species is nutritionally superior to frozen fish, and this is regarding thiaminase and other nutritional components. Of course the caveat to that is concerns over parasitism. However knowing that frozen fish is less nutritious should give you the advantage while developing a menu for your pets.

I think that it is important to see that the specifics are unknown and not many people are looking for answers because the problem has been solved. Zoo's supplement thiamine in true piscivorous species, garter snake keepers feed a variety of prey to counterbalance any deficiencies of any one item. So nothing ground-breaking here, but a lot of food for thought

[d_virginiana]

I think it's worth mentioning that supplementation in piscivorous species (such as orcas) is only a bandaid, and that a deficient diet composed solely of frozen fish will eventually take its toll, leading to a lot of early and unexplained deaths as well as other indicators of poor health (in this case collapsed dorsal fins are probably the most obvious).

This is very unscientific, but I tell people to avoid the colors red and yellow (and any species that can easily produce those colors) if they aren't sure and absolutely have to use something 'unorthodox' as a food item. This includes all carp species like goldfish and rosy reds. It's actually the reason I initially told someone to stay away from silk worms for frogs, and only afterwards did I do some research and find out that they actually contain thiaminase.

I don't remember for sure, but didn't someone on here run into fresh fish that had been treated with a preservative to give it a longer shelf-life that ended up being fatal? Or was that frozen stuff? Hopefully someone who remembers that thread will read this.

[Herp Derp]

I do not have any snakes, but I would suggest using convict cichlids as a food source. They breed fairly often(takes less than a yr for babies to breed themselves), depending on tank size, temp, water quality etc. They are interesting to watch as they actually take care of their babies(break up food and spit it out for them, keep the babies close together and later on herd them around the tank). DO not have any other fish in the tank with them as they will defend and kill most fish in the tank when the eggs have been fertilized. they are pretty hardy fish too so no heater is required(room temp will be fine). Female convict will have a red/pink hue on her belly the males will tend to be bigger and have longer fins. A simple 20g(bigger is always better though) would be good for breeding with a 5" ceramic pot . Do some research first on cycling an aquarium as well. Thiaminase is usually talked a lot more in the aquarists forums for larger predatory fish.

[d_virginiana]

I really don't mean to be as contradictory as I seem to be being in this thread. Maybe I shouldn't visit forums while putting out job applications; I think it makes me a bit meaner lol.

But as I see it the cichlids have quite a few strikes against them; they can't be housed together in large numbers in a small space as I imagine one breeding pair would attack another if they couldn't stake out individual territories and fry would be too small to feed off until they got older; also they require tank parameters that may be simple for an aquarist but are complicated for someone looking for an easy feeder (as compared to something like guppies that can basically thrive in a still tank of tap water).

Additionally we don't know anything about their thiaminase content other than speculation. They don't share a natural range with garters so we have no evidence from the wild of how they'll affect them as a feeder, and they aren't commonly used feeders, so we don't have anecdotal evidence from other keepers either. Several times I've gotten the question of whether it's okay to feed small species of African frog that aren't known to be toxic, and I always caution against it because of those very reasons (for example just offering prey that had been touched and then refused by one of my South American frogs that are considered non-toxic was enough to cause a regurge for one of my garters).

It sounds like these cichlids would be a really interesting species to keep, but IMO too much trouble and too much we don't know about them to recommend as feeders when there are cheap, easy to find, safe alternatives. You're probably correct and they'd be perfectly safe to feed, but we just don't have any evidence for it either way.

[joeysgreen]

I'd have to agree with Lora. Herp Derp, I've bred cichlids before and it was fun, but another drawback is they simply don't produce enough to make a valid feeder colony. The amount of pairs you'd have to have to keep just a few snakes happy would be a lot of work. Just as CB wood frogs would be the perfect feeder, breeding them and raising all those tadpoles to meal size would be an absolute tonne of work.

To add to my previous posts, I do admit to cringing when people say they feed primarily frozen fish; even moreso when it's not whole-body fish. Your snakes may be living, but you're likely walking a very fine line with a nutritionally related disorder.

Lora, I think we can agree that there's a lot more wrong with captive orca's than nutrition. They are perfect example of a species that shouldn't be kept in captivity. With other piscivorous species supplementation is much more successful; be it they supplement more than just Vitamin B1.

[edit] I think the other toxic thread was BlueSirtalis that had the problem. This can be a worry for anything bought that's intended for human consumption. So often there are salts and misc. preservatives and flavors added that we don't see or think about.

Ian

[d_virginiana]

Oh, I agree there is much more than diet wrong with captive orcas. You'll never catch me attending SeaWorld. I just recalled that in Blackfish the diet was cited as being wildly insufficient.

When I got my first garter (now 15 years old) I was 12 and didn't even have access to the internet, so he was fed a diet of primarily fish. Luckily he refused to touch rosy reds and ate minnows. But that and the occasional nightcrawler was all he ate until he was probably about ten years old (I think around the time I found this forum). I often wonder if that contributed to his going blind, or if that's just the result of extreme old age as he's otherwise quite healthy. I know that in turtles vitamin deficiencies can cause problems with eyesight, so I imagine it could be true for snakes as well.

I have to say I think having a little guppy colony is a great idea. Not for adults of course, but it can be a real lifesaver for non-eating scrubs. I put literally zero effort into them other than sprinkling food in and they are thriving.

I've never liked the idea of feeding meat intended for human consumption for that exact reason. I know some people like to be more adventurous in their feeder choices in the name of variety, but I prefer to stick to the most basic diet for all my herps that can supply all their nutritional needs because I'm afraid of running into some unforeseen problem with a feeder that appeared safe.

[Herp Derp]

its all understandable, breeding, culturing your own food for pets takes a lot of extra work. I was just giving the O.P. something to think about.
Even fish need a variety of diet rather than just one simple brand of fish flake. Its all relative to the owner, some owners make sure the food they feed their pets are well taken care of as well(some people gut load crickets and some people dont).
What I think is most important is a varied diet.

[Albert Clark]

Thanks for that information. Well taken.

[d_virginiana]

Just tossing this out there, but since we're talking about raising food, nightcrawlers are by far the easiest and cheapest food to raise yourself. Plus you don't have any of the potential health concerns that come with fish.