Garter Diet Question

[adamanteus]

I thought Xenopus were toxic to snakes, causing oral dyskenesia? You mention in a previous post that most Garters wouldn't encounter trout or salmon in nature.... but Xenopus?

[DrKate]

However I am also not convinced that thiaminase is a problem for fish eating snakes. They are not feeding on trout and salmon in the wild (Ok, T. atratus does), but rather on shad, minnows, etc. Fish that are high in thiaminase.

OK, so, I don't necessarily want to get all into this again, but it seemed worth making a small point... I used to think thiaminase was a problem only with frozen/stored fish, too, for all the reasons you stated. But there are quite a lot of studies on thiamine deficiency in wild salmonids feeding on alewives in the Great Lakes. (Alewives are invasive; the native fish that were the natural prey of the salmonids have low/no thiaminase.) So it does seem that a high enough thiaminase level can actually cause a problem for some predators even when consumed live. I don't think we know where typical feeders such as goldfish, rosy reds, shiners, etc. fall with respect to how *much* thiaminase they contain, so I think it's overly simplistic to say that there's "no problem" as long as the prey is live.

I do agree that a single high-thiaminase meal is unlikely to kill any garter that is otherwise on a varied and adequate diet. My baby Puget ate seven small rosy red minnows ten days ago and is perfectly fine, but he's also eaten guppies, silversides, and pinkies both before and since. But you'll never catch me recommending that to anyone directly, because I don't want their snake's death on my head if I'm wrong.

[adamanteus]

I think the consensus is that a varied diet is the key...... Garters are after all opportunist feeders (there are numerous pics/videos on here of Garters eating all manner of road-kill!) What we need to bear in mind is what is actually readily available to the average keeper.

[GradStudentLeper]

I thought Xenopus were toxic to snakes, causing oral dyskenesia? You mention in a previous post that most Garters wouldn't encounter trout or salmon in nature.... but Xenopus?

*looks up literature..* Why yes. Yes they do. Amend. Do NOT feed Xenopus to snakes. Granted until I saw how dirt cheap lab raised Xenopus were, it never occured to me to even think of using them for the very reason that the snakes might not even recognize them as food. So, I stand corrected there. The rest of the point stands however. Even the bullfrog tadpoles that you can get in bulk are cheaper than mice, and more palatable to just about any natricine (some fish specialist nerodia need not apply)

[jitami]

Breeding guppies in huge numbers is easy...

While it's not difficult per se, it it is a royal pain in the arse! I longed for guppies... I looked everywhere for guppies... I found guppies and started a tank... I would never do it again.... so time consuming for what little you get out of them. Anyone want a tank full? Kidding, but I've thought of freezing the whole lot and being done with them many many many times!

[GradStudentLeper]

OK, so, I don't necessarily want to get all into this again, but it seemed worth making a small point... I used to think thiaminase was a problem only with frozen/stored fish, too, for all the reasons you stated. But there are quite a lot of studies on thiamine deficiency in wild salmonids feeding on alewives in the Great Lakes. (Alewives are invasive; the native fish that were the natural prey of the salmonids have low/no thiaminase.) So it does seem that a high enough thiaminase level can actually cause a problem for some predators even when consumed live. I don't think we know where typical feeders such as goldfish, rosy reds, shiners, etc. fall with respect to how *much* thiaminase they contain, so I think it's overly simplistic to say that there's "no problem" as long as the prey is live.

I do agree that a single high-thiaminase meal is unlikely to kill any garter that is otherwise on a varied and adequate diet. My baby Puget ate seven small rosy red minnows ten days ago and is perfectly fine, but he's also eaten guppies, silversides, and pinkies both before and since. But you'll never catch me recommending that to anyone directly, because I don't want their snake's death on my head if I'm wrong.

If you have references to those studies, I am interested (particularly as it relates to the mechanism of the deficiency). Bear in mind as well that different organisms have different thiamine needs. The prey fish in question (Alewives) may not contain enough of it to provide for the needs of Salmonids, irrespective of the amount of thiaminase, as that WILL be broken down by digestion and not go into the animal's system to destroy what thiamine it has in system.

I certainly agree with the varried diet. If for no other reason than because the snakes get bored. But also because of nutrition. You need a staple diet that provides for most of their nutritional and caloric needs without supplimentation, but chances are you WILL be lacking in some nutrient. So variety is your friend. If you have the capacity to feed a wide variety of food, do it. I live in a place with a LOT of native fish and amphibians that have nice stable populations, and a lab that soon will produce WAY more tadpoles than I need (one female bullfrog will lay up to 47 thousand eggs... I have 4, and only need 5 thousand eggs per experiment...), and can easily breed guppies and can buy annelids if I want to give my garters some boneless treats... others might not be able to do this, but there are ALWAYS options for that sort of variety.

[Zephyr]

If it's an eastern garter snake, it may be adapted to eating worms, fish, or frogs.
What species do you have?

[DrKate]

If you have references to those studies, I am interested (particularly as it relates to the mechanism of the deficiency).

If you've got access to Aquatic Sciences & Fisheries Abstracts through your university library, use "thiaminase" and "alewife" as search terms and set the fields to "Anywhere." There are loads of studies, I only read enough of them to convince myself the salmon had thiamine deficiency and were eating the alewives live. If you don't have access to ASFA, PM me and I'll send you a list of the search results. Since the OP asked a very practical question, I don't want to further clog the thread with academic nonsense.

[adamanteus]

I don't want to further clog the thread with academic nonsense.

I'm sure the original poster will appreciate that, Kate.
That said, the discussion between yourself and Benjamin on the question of thiaminase is fascinating and relevent, and obviously you have both researched the subject. Perhaps one of you might consider starting a thread devoted to this topic?

[DrKate]

Perhaps one of you might consider starting a thread devoted to this topic?

Haven't we already got several?

I'm not being flippant, really. I feel like I've been looking up thiaminase info and making posts about it for weeks, anyway. In particular there's the recent "I have fed my garter goldfish for 13 years" thread. Unfortunately I think the really crucial pieces of information - what exactly is the garter snake's dietary requirement for thiamine, and how thiamine-deficient (or how variable in thiamine/thiaminase content) are goldfish/rosy reds/shiners as a diet - are simply not known, which is why all we ever come up with is "avoid thiaminase-containing fish" and "feed a varied diet."