Quote:
Originally Posted by tikichick
Interesting question. Is thiaminase naturally present at a high level in goldfish, or is it a result of captive fish-flake diets?
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From my research, all goldfish have it. I can think of one main argument against goldfish, aside from the thiaminase *which is supposedly in larger amounts in goldfish as compared to rosies*: Goldfish are native to Asia, and rosies are native to many of the areas where garters live. Rosies, AKA fat head minnows, are natives of the US and the gold strain is simply a cultivated variety. In the wild, I have observed many aquatic and semi aquatic snakes eating fatheads, which are on the list of thiaminase containing species. Some of the other American species of fish, such as sunfish, do not contain thiaminase, or at least not in noticeable levels. However, from personal experience, I have never seen a garter go after sunfish, except by accident when the young school with baitfish minnows, such as rosies. Also, sunfish spines are VERY sharp, and my old snake Cremepuff could barely fit down a 3-inch bluegill, and he/she was around 3 feet. So, my conclusion is that minnows and other cyprinids are a common part of garter snake's diet, but are not their exclusive choice. Therefore, I conclude that a staple diet of rosies, combined with a scheduled rodent or amphibian, is a healthy and natural diet for these snakes.