Smelt & silversides

[aSnakeLovinBabe]

Remember when I found some "smelt" at my grocery store and was bummed when you guys said they contained thiaminase? Turns out, the "smelt" they have at this store are actually silversides! And they are safe after all! Just wanted to share this information, which I considered to be relatively valuable, it's a group of PM's from a fish keeper on another forum who asked some companies what species of fish they sell as silversides, and he also helps explain the difference between silversides, and true smelt. It really helped me out and assured me that the silversides I am using, with their silver side stripe, one spiny and one soft fin, are the real deal. True silversides don't contain thiaminase, whereas true smelt do. Because of this silversides are the choice food of aquarium hobbyist's predatory fish because the thiaminase issue is just as prominent with them! Just be careful, not all brands selling frozen fish labeled as silversides, are actually using the real silversides. Here is the rather long winded group of messages:


Silversides are a completely different species than true smelts.

They are commonly sold as jack "smelts" in stores but they are not true smelts. They do not contain thiaminase.

The tropical fish community has the same concerns about thiaminase as the reptile community - that's why frozen silversides are a staple for carnivorous fish.

Smelt come from the family Osmeridae. Neotropical Silversides come from the family Atherinopsidae.

Silversides are often called smelt, even though they are not.

The Osmerus smelt that were outlined in the Fox/Mink reference came from the Great Lakes (if memory serves me). There was a big issue at the time with alewives and high thiaminase levels affecting the reproduction of trout and salmon in the lakes. One theory I heard was that the osmerus mordax and the alewives were eating a type of cyanobacteria which harbored the bacteria producing the thiaminase enzymes.

This theory was partially reinforced by the fact that other smelt species tested negative for thiaminase.

Anyway, the problem with the thiaminase charts is that they are outdated and incomplete. Silversides sold as aquatic fish food are considered safe and even enhanced with thiamine and Vitamin B12. They are more often than not confused with smelts when they are young.

The visual differences being that the menidia (silverside) lacks the adipose fin of the smelt as well as the fact that the menidia has two dorsal fins - one spiny and one soft - while the true smelt only has one soft dorsal fin.

I have an e-mail in to several silversides packager to get the info on the actually exact species of atherinidae they use - as well as any thiaminase studies they have used.


Dear Craig,

Thank you for your interest in San Francisco Bay Brand. The species of silverside is the Atlantic silverside, Menidia menidia. If I can be of further assistance please let me know.

Hikari is using pseudohemiculter dispair which is a cyprinid (as are goldfish and other known carriers of thiaminase. My bet would be that they contain thiaminase - the rep even wrote back that they add thiamin to these fish to counteract thiaminase.

That's junk science and doesn't help - Hikari should know better. Hikari silversides are not silversides and should be avoided.

H20 Life Foods says that they use "blue anchovies" from Vietnam. These could be either engraulidae, stolephorus or cetengraulis. The fact that they can't tell me which species it is and the fact that they are - like Hikari - mislabeled as silversides is a big red flag.

Engraulidae are confirmed carriers of thiaminase. So H20 Life Foods also is a no - no.

Unlike SF Bay brands, both Hikari and H20 Life are guilty of selling non-silversides as silversides.

[drache]

thanks Shannon - that is helpful

[MoJo]

Are these fish small enough for baby garters?

[aSnakeLovinBabe]

no, they are pretty big, only a good sized adult or juvenile can eat a whole one, at least in the sizes i buy them. I cut them into pieces for the little guys.

[car24]

Thank you Shannon! I have been feeding them to my lionfish for years. My snake loves these! I buy the San Francisco Bay Brand from my fish store. They come frozen in a flat and the sizes of the fish is a mix from 1/2 to 2 inches.

This is Bugzy my lion!
546

[Stefan-A]

In regards to what Shannon pointed out concerning smelt, European smelt (Osmerus eperlanus) is an exception, it does not contain thiaminase. However, most, if not all other species, do.

[kimbosaur]

Reviving an old thread - I am very concerned that the "Silversides" I have been feeding are not actually silversides. They look very different from some pics I see on this forum and are pretty much completey white. They also are very tiny...small enough for babies to eat whole no probem. The brand is OmegaOne and I contacted them asking what species they use and they responded:
Thank you for contacting Omega One I apologize for the delayed response.* We've checked with our supplier, and to their knowledge, our silversides do not contain thiaminase. In any case, thiaminase is only an issue in very high quantities; therefore, if you make sure to give your fish a variety of different foods, this will never be an issue. I hope this helps. We look forward to your continued support. Please let us know if you have any other questions.....not exactly helpful. Are these safe? They are the only brand I could find.

[d_virginiana]

Reviving an old thread - I am very concerned that the "Silversides" I have been feeding are not actually silversides. They look very different from some pics I see on this forum and are pretty much completey white. They also are very tiny...small enough for babies to eat whole no probem. The brand is OmegaOne and I contacted them asking what species they use and they responded:....not exactly helpful. Are these safe? They are the only brand I could find.

Who are you feeding with them? If you're feeding babies, feeder guppies are always an option, even though they can get expensive if that's all you ever feed. I've never used silversides so idk a lot about how they're supposed to look, but is it possible that they just harvested juveniles or something?
I wouldn't worry about it overmuch right now. The majority of the cases of thiaminase poisoning I've read about are with ribbons who have been fed rosy reds their entire lives. I mean, it's better not to risk it if you can help it, but the occasional fish from the 'bad list' shouldn't hurt your snakes, especially if you're giving them plenty of other food items.

[aSnakeLovinBabe]

I'm pretty sure I've used those fish you are referring to! They are babies which would explain the white color and their weird black eyes. They are very long and skinny too! I always have to cut them in half. I've used them on occasion with no problems... They don't resemble their adult counterparts in any way though, but that is because they are fry.

[snakehill]

I just bought silversides for the first time. Are they extremely smelly or did I get a bad bunch? :confused:

[Selkielass]

The ones I get from petsmart are extremely smelly. I only feed these when I have to due to the smell, fresh and on their way out.

[aSnakeLovinBabe]

If it's just a "fishy smell" then it's fine. Sometimes they do have a pungent odor... they are fish after all!

[snakehill]

They are really bad! My garters wouldn't eat any but my cats were very interested! I'm not sure it's worth the smell! It doesn't seem to go away! :p

[Selkielass]

Extremely smelly, in my experience, but some batches are worse than others.

[RedSidedSPR]

Sally's brand silversides are safe, Kim. That's all I know


I just bought silversides for the first time. Are they extremely smelly or did I get a bad bunch? :confused:

They're pretty bad. lol

[kimbosaur]

I'm pretty sure I've used those fish you are referring to! They are babies which would explain the white color and their weird black eyes. They are very long and skinny too! I always have to cut them in half. I've used them on occasion with no problems... They don't resemble their adult counterparts in any way though, but that is because they are fry.

Actually they do look like fry! Big eyes with white bodies exactly like you described. I've been using them relatively frequently, like every third feeding, so I wanted to make sure.


Sally's brand silversides are safe, Kim. That's all I know
I can't find Sally's here...Only Omega One. Found a pic - you can kind of see how they look.

http://www.reefsolution.com/catalog/images/10587.jpg

[RedSidedSPR]

Actually they do look like fry! Big eyes with white bodies exactly like you described. I've been using them relatively frequently, like every third feeding, so I wanted to make sure.


I can't find Sally's here...Only Omega One. Found a pic - you can kind of see how they look.

http://www.reefsolution.com/catalog/images/10587.jpg

Those looks weird.. i don't know..

Only place I know where to get them is Pet stores, which is why I'm never buying them. Too much $$... but it lasts a long time with a few babies.

[aSnakeLovinBabe]

Yep! That's them! Mine aren't the same brand but those are the fish. My mom calls them gross spaghetti fish. LOL

[RedSidedSPR]

Yep! That's them! Mine aren't the same brand but those are the fish. My mom calls them gross spaghetti fish. LOL

WHAT

Really?? Those look so different

[snakehill]

I bought adult silversides. Do they like the fry better? :confused:

[ConcinusMan]

WHAT

Really?? Those look so different

Those are "baby" silversides Jesse. I've never seen them sold like that. I've always used silversides that were 3-6 inches long and look like this:

http://www.fisheries.vims.edu/ctils/prey2/silversides.jpg

[RedSidedSPR]

I see. Yeah that's what I get too


Those are "baby" silversides Jesse. I've never seen them sold like that. I've always used silversides that were 3-6 inches long and look like this:

http://www.fisheries.vims.edu/ctils/prey2/silversides.jpg

[aSnakeLovinBabe]

The fry are great for baby snakes and I take adults and chop them in half for the big snakes!

[RedSidedSPR]

I wanna find the fry now.:D My adult won't eat em so not having to chop them would be cool

[kimbosaur]

*Sighhh* I've been going around trying to find the adults because all I have are the baby ones...maybe we should just somehow trade. :rolleyes:

[ConcinusMan]

I would think that the fry wouldn't have as much calcified bone as the adults.

[kimbosaur]

Apparently some PetSmarts around here have the Sally's brand. Now I'm annoyed that the three in my immediate area don't.

[ConcinusMan]

I just bought silversides for the first time. Are they extremely smelly or did I get a bad bunch? :confused:

It really wouldn't matter if they are a bit rancid. That won't hurt your snakes at all. If you bought them frozen from a pet store and they are sold as carnivorous fish food, they are the thiaminase-free kind. Arctic Pond Smelt, which really isn't a true smelt, and really doesn't live in ponds. It's a saltwater fish.:rolleyes:

They are thoroughly rinsed in, and sometimes packed in, fresh water. No worries about salt content. SF Bay brand are supplemented with vitamins/minerals BTW so if your snakes are eating that brand, there's no need to give them additional supplements.

[ConcinusMan]

Apparently some PetSmarts around here have the Sally's brand. Now I'm annoyed that the three in my immediate area don't.

I prefer the Sally's flats. They smell fresher, look fresher because they are packed in water, and are not supplemented. The SF Bay brand are merely vacuum sealed dry, and have added supplements.

[snakehill]

The silversides I purchased are "Ocean Nutrition" brand. I got them at Petco. They are sold as fish food.

[nekura]

Can you post pictures of the true non-dangerous ones? I buy the frozen at pet-smart. Its the San Fransisco Bay brand called Sally's 100% Natural Silversides
.

[kimbosaur]

Diagrams from Wikipedia:



http://upload.wikimedia.org/wikipedia/commons/9/99/Atlantic_silverside.jpg
http://upload.wikimedia.org/wikipedia/commons/1/19/Osmerus_mordax_(line_art).jpg


Silverside
Smelt




From the original post:

The visual differences being that the menidia (silverside) lacks the adipose fin of the smelt as well as the fact that the menidia has two dorsal fins - one spiny and one soft - while the true smelt only has one soft dorsal fin.


I feel like it would be really hard to see the difference visually on a frozen fish at the supermarket, but apparently the Sally's brand are safe so you should be good. :)

[nekura]

Okay, thanks =)

[ConcinusMan]

Sally's and SF Bay brand have both been confirmed to be the right kind. Pond smelt - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Pond_smelt) I wrote both companies and got a reply indicating the Latin species name. They are farm raised and so, no mixing of species. They are thiaminase free Arctic Pond Smelt Hypomesus olidus. Not a true smelt. A freshwater fish that inhabits the arctic. They are very high in fat compared to rodents, but other than that, they are very good for your garters. "silversides" from the grocery store, are often in fact, true smelt, which contain thiaminase.

I prefer the Sally's because they are packed in water, and are much fresher. The SF Bay brand are vacuum sealed, and tend to lose vacuum and dry out and/or freezer burn before you even buy them. Check the package to make sure it has a good seal. You shouldn't see air pockets or frost buildup on them. After opening, I suggest you refreeze them in water to keep them fresher, longer.

[kimbosaur]

So I've just heard back from the company (Omega One):


Hi Kim,

I apologize for the delayed response. Brachyrostralis is the species name for the Silversides we use.
Have a great day!

Best Fishes,


Allison

Customer Care

Omega One






When I google Brachyrostralis, barely anything comes up. What's the deal?

[ConcinusMan]

They must mean Hemisalanx brachyrostralis . Like I said, the common name for "silversides" is often applied to any small fish with silvery colored sides, including some species of smelt. Hemisalanx are related to true smelts. Some smelts have thiaminase. Some do not.

SF Bay Brand and Sally's are the only brands that I could confirm as being Hypomesus olidus, which is a species that does not contain thiaminase.

[kimbosaur]

Arghhh, I can't find any other brands. I guess I'll just have to keep looking. Also, aren't SF Bay and Sally's the same thing?

[ConcinusMan]

Yeah, sorry 'bout that. I meant Ocean Nutrition, and SF Bay Brand. They're both Hypomesus olidus. Other brands could be thiaminase containing smelt.

Ocean Nutrition adds supplements and aren't very fresh. SF Bay Brand "sally's" don't have added supplements and are much fresher.

Oh, and BTW, this is the correct illustration/pics for Hypomesus olidus.
http://upload.wikimedia.org/wikipedia/commons/thumb/2/2b/Pond_smelt_illustration.jpg/800px-Pond_smelt_illustration.jpg

http://content61.eol.org/content/2009/09/16/07/82410_580_360.jpg

I stated earlier that they are not a "true" smelt. That's incorrect. It's the other "silverside", pictured in posts above, that is not a smelt. Anyway, even though they are a smelt, the species Hypomesus olidus, / Arctic Pond Smelt, lacks thiaminase.

[kimbosaur]

Oh, I was going by the original post:


Dear Craig,

Thank you for your interest in San Francisco Bay Brand. The species of silverside is the Atlantic silverside, Menidia menidia. If I can be of further assistance please let me know.



The visual differences being that the menidia (silverside) lacks the adipose fin of the smelt as well as the fact that the menidia has two dorsal fins - one spiny and one soft - while the true smelt only has one soft dorsal fin.

[ConcinusMan]

You know what's funny about that is that I wrote them too and they gave me a different answer. They told me they were Arctic Pond Smelt. Hypomesus olidus. And by looking at the fish in the package I had, and comparing I.D. keys in the internet, they were definitely not menidia. And Ocean Nutrition also told me they were Hypomesus olidus. Either way, niether species contains thiaminase. That particular species of smelt doesn't contain thiaminase according to info I could find.

[kimbosaur]

Since I received the reply from Omega One, I have found a few articles on the species "Brachyrostralis" and it appears that they are an "ice fish" native to the Yangtze River of China. The only references I can find to the species are Chinese. I find it very strange that there is so little information on a fish that is mass sold across the world. Could it be possible that there is another name for them?

Nevertheless, I don't feel comfortable with this source of "silversides" and will continue to be on the hunt for some of those other brands.

[RedSidedSPR]

Pet stores should carry Sally's brand. That's what I use.

[Steveo]

Breathing some life into this old thread... are parasites a concern with frozen fish?

[guidofatherof5]

Depends on the temp they were frozen at and the length of time they've been frozen.
Many parasites are killed by freezing. It's the parasite eggs that can survive much longer that are the concern.

http://seafood.ucdavis.edu/pubs/nematodes.htm

[Steveo]

Thanks, Steve. I'm hoping to pick up some silversides this weekend, hopefully the packaging will indicate temperature and length of time.

[ConcinusMan]

It won't, but they are flash frozen (nearly instantaneously frozen at extremely low temperature using liquid nitrogen) before they are packaged, and kept frozen until you buy them. I wouldn't worry about parasites at all, and I've never seen any signs of worms, dead or alive, in the silversides. Can't say that about fish meant for human consumption.

[mibr]

In regards to what Shannon pointed out concerning smelt, European smelt (Osmerus eperlanus) is an exception, it does not contain thiaminase. However, most, if not all other species, do.

Sccording to information on thamnophis.eu (/thamnophis/?page_id=884) the species Osmerus eperlanus does contain thiaminase.

[mikec205]

I catch my own silversides and they are a smelly fish when they are still alive.