I have fed my Garter/Ribbon Goldfish for 13 years. Is Thiaminase a problem?

[Stefan-A]

While I was out Herping yesterday I came across a field mouse. I was able to catch it and kill it. The whole time I thought my Speckle or JW (my two biggest girl) would love to have a full grown mouse. On the way home I knew I was going to freeze it for a couple of months just to make sure parasites weren't an issue. At one point it hit me, I had no idea what this rodent had be eating or what other problems could occur with feeding it to my snakes. Out the window it went. Better safe than sorry. I have a very difficult time losing any of mine. I don't want it to happen because of something I did or didn't do. Safe foods all the way here at the T.r adix Ranch

Yeah, that's a major reason why I don't want to use wild rodents. They will chew and swallow just about anything.

[DrKate]

They put some additive that contained some copper compound or something.

I'm pretty sure what you're talking about is copper sulfate. It's a *very* common anti-protozoal (e.g. kills "Ich") treatment for fish, available over the counter and commonly used in overcrowded/stressed situations to prevent disease in the fish. I have no personal knowledge of its effects on snakes, but I'm sure that's the compound you're thinking of.

AND...

My question about the frozen thawed aspect of thiaminase is - if my silversides didn't have it in them when they were alive, surely I don't see it spontaneously appearing when they are frozen and stored

You are exactly right. I'm sorry I wasn't clearer about that. Different species (and populations) of fish naturally contain different levels of thiaminase. Some fish contain enough to be a problem even when very fresh (e.g. live). When *any* fish is dead and stored for some time, whatever thiaminase is present has time to break down the thiamine in the tissue of that fish. (Poor storage, e.g. too high a temperature, is also an exacerbating factor.) The stored fish become deficient in thiamine and lead to nutritional deficiency in the predator.

So it's not that thiaminase spontaneously appears, or even becomes more potent, in stored fish. It just has more time to do its job. And the more thiaminase that's there to start with, the more thiamine will be broken down during storage. The fish we talk about as "safe" are the ones that have extremely low levels of (or maybe no?) thiaminase, so not much (or no) thiamine is lost during storage. There are other fish (like herring for marine mammals) that have low enough levels to be safe when fed fresh/live, but cause problems if stored a long time. And then there are those species - like goldfish apparently, given the range of personal experiences here - that just vary so widely we can't really trust them.

If we knew exactly what it was about diet/environment that caused a particular population to have high or low levels of thiaminase, then presumably we could just raise low-thiaminase feeder goldfish. But without doing biochemical testing on each batch I don't know that there's currently a way to be sure that any particular batch happens to be safe.

Whew! Sorry for the long-winded reply. There just seemed to be some lingering confusion that I thought I could help clear up...

[MasSalvaje]

Excellent topic and discussion, thanks to all that are involved.

One question, I know I have seen a link posted on this site for a list of "safe" fish, does anyone have that link? Is it complete/the best one to use?

-Thomas

[ssssnakeluvr]

here's the link....

Nutrient Requirements of Mink and Foxes, Second Revised Edition, 1982
Nutrient Requirements of Mink and Foxes, Second Revised Edition, 1982

how are the babies doing?? the female I got is getting huge!!!!

[bkhuff1s]

I would scent the pinky w/ the fish

Step 1. Drain all but a tiny bit of water from the fish bag
Step 2. Place the thawed pinking into the corner of the bag (remaining water and all the fish should be there
Step 3. Swish around (I usually do it about ten times)
Step 4. Dump all of the contents into the snake enclosure or feeding tub
Step 5. Watch as the snakes goes into "OH MY GOD FISH" mode

[Millinex]

I would scent the pinky w/ the fish

Step 1. Drain all but a tiny bit of water from the fish bag
Step 2. Place the thawed pinking into the corner of the bag (remaining water and all the fish should be there
Step 3. Swish around (I usually do it about ten times)
Step 4. Dump all of the contents into the snake enclosure or feeding tub
Step 5. Watch as the snakes goes into "OH MY GOD FISH" mode

I've also found taking a single fish and using it to rub down the mouse excessively works very well, incase you didn't want to buy a bag of fish

[bkhuff1s]

That's true I used guppies, so a bag of goldfish would probably be excessive. A bag of guppies, being 10, was only a dollar.

[Millinex]

In my stores minnows (guppies some call them) are the same price as goldfish, goldfish are such garbage feeders though ;*O

[jitami]

Welcome

I'm also in Sacramento and also have two wild caught adult garters just like yours. They're Thamnophis elegans elegans. In my experience, and everything I've read, they're pretty easy to switch to rodents. Just scent it heavily with fish the first couple of times or put it in the bowl with one or two live fish. When I switched my male I scented the pinky mouse with a frozen minnow the first couple of times and now he prefers mice to anything else. The female that showed up in my driveway last summer was even easier. I 'brained' a frozen thawed pinky(stuck the knife through it's skull until some fluid ran out) and she took to the pinkies right away. They both like the occasional live fish, but really prefer frozen thawed mice over frozen thawed fish fillets(tilapia/trout/salmon) and neither likes worms. What you're doing obviously works for your snake, but I'd try to move away from the goldfish if you can.

I'd love to see/hear more about your snake, too I have pics of my guys here: http://www.thamnophis.com/forum/gene...amis-kids.html

[DrKate]

In my stores minnows (guppies some call them) ...

Sorry, my inner biologist is refusing to let me just let this go... Guppies and minnows are really completely different things. Minnows and goldfish are both in the Cyprinid family (along with carp and barbs). Some minnow species can have high levels of thiaminase just like goldfish ("rosy red minnows" are often mentioned on this forum as an example). Some minnows may be safe to feed, I'm not sure, you'd have to check that list linked to a few posts back.

Guppies on the other hand are in the Poecilid family and do not have high levels of (or perhaps any) thiaminase. In most pet stores you're more likely to find fancy guppies, meant to be kept as pets (and selling for $2 each). But some stores sell plain guppies (usually less than an inch long) as feeder fish. I've found that at least in my area, a tank of "feeder guppies" often actually contains a mix of guppies and a related species, the Endler's livebearer. Doesn't matter from the snakes' point of view, both are safe to feed - and equally yummy, judging by my boys' reaction to them.

Anyway, I'm sorry Millinex, I don't mean to be rude in the least, but since the distinction is actually important when it comes to feeding snakes, I thought it was worth correcting the mistake.