The myth of feeding marine predators fresh water fare

[lion king]

I don't feed goldies or rosies, but all of my 10 predators get a combo of fresh water ghosties, guppies, and mollies. While there may be a foundation of how bad it is to feed goldfish and possibly minnows to your lions, scorps, and anglers; I know people that do and keep their preds for years. On the other hand, the gang that teach "train your pred" to eat dead food; never keep them more than a year to year and a half. So go figure, there's got to be something there.

The fresh water ghosties that most of us have access to, are actually a variety of shrimp that live in fresh, brackish, and salt water. They are cheaper, easier, and live longer in fresh water. Gut load them and enhance them with multi vits and efa's and you have a very nutritional food that can be the staple of your pred's diet. If you have to keep the marine version of a feeder shrimp; expect to spend more and incur greater losses, as well as if not kept in "no fish" symptom, the possibility of spreading disease.

Feeder guppies are nice for smaller guys, you can house them with your ghosties and enhance them similiarly. You get some bones and guts that I believe are very necessary to the long term health of preds. If you have a lfs with a high volume fresh water business, you can likely find mollies of all sizes available. I've gotten baby mollies for as little as 5 or more for a $1 and I get large ones for a $1 each. It's also easy to breed your own mollies, but growing out for larger preds may not be worth it. Feeding any salt water prey would require qt and deworming/parasite treatment, and consider any treatment could contaminate the food, just as mercury does for human; so no fish from copper systems as well.

This diet has served me well, I have had some of my current crew for over 7 years, a fu manchu coming up on 8 years. I'm posting in response to still seeing post in regards to not feeding marine preds fresh water food and still running into people at the lfs that repeat this teaching. While it may not be the perfect diet, it is this best we can do. Most people that continue to teach not feeding fresh water food or training to dead food don't have the long term success these guys deserve, at least in my experience.

 

[reef lover]

Interesting....

 

[Squeaky McMurdo]

You know, if you look at the live food as the vessel for transferring the nutrients, it doesn’t matter where it comes from. It’s just a pill pocket and what you gut load with is what really matters.

That’s probably the real reason goldfish and feeder minnows straight from the store aren’t a good dietary option. They’re likely fed the cheapest goldfish flakes that are 90% flour because they aren’t expected to live long anyway.

 

[lion king]

Some additional nutritional info; I'm sure everyone has heard of thiaminase and how deadly it can be. What thiaminase does is bind thiamine(vitamin B1) and as a result your fish could get a B1 deficiency. This deficiency could prove deadly after several months.

The problem with rosies and goldies is that they contain thiaminase. Silversides in the form of rainbow smelt also contains thiaminase as well as as krill. Feeding any of these exclusively or just a combination of these exclusively over the long would prove deadly. But having these as a part of a diet is not going to kill them, as long as the dominant part of their diet will have an adequate amount of vit B1.

A varied diet with supplementation and gut loading paying special attention to thiamine(vitamin B1) could be very beneficial. Since vit B1 is water soluble you can't really od on it, maybe even researching a specific B1 supplementation. Finding completely thiaminase free food may be near impossible, one report will say ok while another will warn against the same food, Salmon is one example, the reason I see no problem feeding salmon is that it is high in B1, so basically balancing out the negative effect of thiaminase.

Mollies and guppies have never been associated for containing thiaminase. I couldn't imagine gut loaded ghosties being a problem either. I have kept many fish prone to vitamin B1 deficiencies like lions, puffers, and eels well over a decade. I have included foods known to contain thiaminase like krill and various forms of smelt, but the key was to not feed these foods exclusively, and supplementation.

 

[Squeaky McMurdo]

I didn’t know that lion king, but I happen to know that you can buy a large bottle of injectable B complex for around $6 at any feed store like Tractor Supply. Many antibiotics and anti-parasitics bind thiamine so I wonder if they’re throwing those at those little farmed fish. Side note: My TSC has fish medication because of aquaphonics becoming popular.

 

[lion king]

One thing you have to be aware, a molly is not a true fw fish, they are brackish. many of them live and breed in sg as high as 1.017. The ghosties we get are a variety of shrimp that also lives in fw, brackish, and salt water. While the fresh water feeder guppy is fresh water, you can acclimate guppies to salt. So there may be be something that sets this combo of fw feeding apart.

With that being said another repeated bit of info is that fw fish don't contain the proper fats and that marine fish can't digest them properly. Partially true in the case of rosies and goldies, most of what you may read is likely based on info passed on from the days when rosies and goldies were the only live feeders being used.

Let's talk supplementation, efa's(essential fatty acids) and a good multivit. Using an efa like Selcon or Brightwell Aminomega may address some concerns with the proper type of fats. Selcon is the gold standard while I really like the added elements in the aminomega, like vit C and thiamine. I put a few drops on my feeder's food and use a Brightwell technique of dosing a feeder container 20-30 minutes before feeding ghosties. A few drops in the feeder container is suppose to tissue absorb and the ghosties may actually nibble on the droplets. Mollies likely carry an abundance of proper fats already.

Multivit; Vita-chem marine formula and Brightwell Vit M. I've used Vita-chem for likely 30 years, it's gotten even better, supposedly an advanced tissue absorbing method. I like the analysis of the Vit M but really hate the smell. I dose thisa multi vit into my feeder tanks.

I feed dead minimally and try to add a few drops of efa and vits to a feeding. Choices, choices; there's alot of good products out there, these are just the ones I use. Using an efa and a good mutivit is likely a good benefit, I beleive you can get an all in one today.

 

[Terri Caton]

Wouldn't Silversides work? I know they are dead and can't be gut loaded naturally but they can be stuffed with vitamins and Selcon.

I read that you feed yours on a long, stiff stick. What do you mean? You spear the live fish and then feed it to the fish?

 

[El_Guapo13]

 

[lion king]

Wouldn't Silversides work? I know they are dead and can't be gut loaded naturally but they can be stuffed with vitamins and Selcon.

I read that you feed yours on a long, stiff stick. What do you mean? You spear the live fish and then feed it to the fish?

Silversides is a good food to feed, but all the predatory fish Im talking about dont always eat dead food, or not enough to sustain long term Siversides is a type of smelt and so.e brands use a variety that is high in thiaminese, so they need to he fed sparingly. Hakari brand is thiminase free. Silversides is a good addition. When Im talking about using tonggs or a stick, Im using dead food.

 

[solitude127]

@lion king Would frozen anchovies (like the ones used for bait) be a good source of nutrition anglers?

 

[lion king]

@lion king Would frozen anchovies (like the ones used for bait) be a good source of nutrition anglers?

Off hand I can't answer that as I have never used them. One thing search and find if they contain a large amount of thiaminese. You have to also see if there are other ingredients. If you are using frozen you would be better of using Hikari silversides from the lfs. I'm also not sure of their structure, as rosies will lodge themselves in the gut and cause bloat.

 

[ctopherl]

I don't feed goldies or rosies, but all of my 10 predators get a combo of fresh water ghosties, guppies, and mollies. While there may be a foundation of how bad it is to feed goldfish and possibly minnows to your lions, scorps, and anglers; I know people that do and keep their preds for years. On the other hand, the gang that teach "train your pred" to eat dead food; never keep them more than a year to year and a half. So go figure, there's got to be something there.

The fresh water ghosties that most of us have access to, are actually a variety of shrimp that live in fresh, brackish, and salt water. They are cheaper, easier, and live longer in fresh water. Gut load them and enhance them with multi vits and efa's and you have a very nutritional food that can be the staple of your pred's diet. If you have to keep the marine version of a feeder shrimp; expect to spend more and incur greater losses, as well as if not kept in "no fish" symptom, the possibility of spreading disease.

Feeder guppies are nice for smaller guys, you can house them with your ghosties and enhance them similiarly. You get some bones and guts that I believe are very necessary to the long term health of preds. If you have a lfs with a high volume fresh water business, you can likely find mollies of all sizes available. I've gotten baby mollies for as little as 5 or more for a $1 and I get large ones for a $1 each. It's also easy to breed your own mollies, but growing out for larger preds may not be worth it. Feeding any salt water prey would require qt and deworming/parasite treatment, and consider any treatment could contaminate the food, just as mercury does for human; so no fish from copper systems as well.

This diet has served me well, I have had some of my current crew for over 7 years, a fu manchu coming up on 8 years. I'm posting in response to still seeing post in regards to not feeding marine preds fresh water food and still running into people at the lfs that repeat this teaching. While it may not be the perfect diet, it is this best we can do. Most people that continue to teach not feeding fresh water food or training to dead food don't have the long term success these guys deserve, at least in my experience.

So there are no concerns of parasites/worms from FW fish/invertebrates? How often do you feed the live foods (specifically for dwarf lions)?

 

[lion king]

So there are no concerns of parasites/worms from FW fish/invertebrates? How often do you feed the live foods (specifically for dwarf lions)?

I have never encountered a disease transferred from a fw fish or invert. I have fed as many 13 predators from the same source and have never seen it. I have been advised from some that the fish can carry parasites that can transfer, but again, in 20 years have never encountered it. Inverts, as in ghost shrimp, I would say a hard no way. But, the problem with feeding marine inverts, is that suppliers will keep their inverts connected to the same system as fish, and fish disease can hitchhike on the bodies of the inverts. I keep my lions and scorps in captivity close to the full lifespan they could achieve in the wild by feeding this diet.

 

[Axelrodi202]

Do you have any experience or thoughts on the use of freshwater Neocaridina or Caridina shrimp as food for lions and other saltwater predators?

Also for something small like a fu manchu lionfish, what amount of live food animals would one need to feed per week, if feeding a mix of live and dead? I have plenty of experience keeping and breeding freshwater livebearers but wonder how many it would take to keep a small lion like that going. As I understand it they don't eat particularly frequently to begin with?

 

[lion king]

Do you have any experience or thoughts on the use of freshwater Neocaridina or Caridina shrimp as food for lions and other saltwater predators?

Also for something small like a fu manchu lionfish, what amount of live food animals would one need to feed per week, if feeding a mix of live and dead? I have plenty of experience keeping and breeding freshwater livebearers but wonder how many it would take to keep a small lion like that going. As I understand it they don't eat particularly frequently to begin with?

I personally have never used Neocaridina shrimp, for me the volume I need it would not work, so I've never fully researched them. My concern would be digestibility, are their shells hard or soft. I don't know anyone that has kept a predator long term offering them neo shrimp. It would be interesting if someone did a project with neo shrimp, a small planted tank could also include breeding guppies or endlers. I would think a small tank breeding guppies/endlers and neo's could supply a small predator as part of a diet with dead food. A baby or juvi may eat every other day and an adult would eat a couple times a week, but they eat alot at each feeding. An adult fu manchu could eat about 15 neo's and 4 guppies a week, that's on the low side.

Here's one of my 10g planted tanks, the neo's do breed like crazy, and I don't even try.

 

[lion king]

UPDATE to my analysis on the choices of live food I recommend. I get challenges to my recommendations of ghosties, guppies, and mollies. 1st off it is based off of more than 20 years of feeding dozens, over a hundred different predatory fish. This hobby is not absolute and anyone can find fault with anything, I have just determined that these are the safest choices that will provide the necessary nutrients to provide a very long life. Sometimes you just have to include live foods, whether the pred just refuses to accept live foods, or species which notoriously don't live long on a dead only diet. You have to make the "best" choices, maybe not the only choice, but the best. I strongly suggest not using feeders from marine sources, unless you are getting shrimp from a source that does not plumb their invert systems with fish. Although inverts will not be affected by fish diseases, fish diseases will hitchhike into other tanks and infest your fish. While I have been repeatedly warned about internal parasites from guppies and mollies, I have never seen it in over the 20 years I have used them. As a high recommendation, I do strongly suggest you breed your own. Today the sources of guppies and mollies are highly compromised by poor and polluted waters and heavily dosed with med cocktails.

The species of ghost shrimp that many find available are euryhaline species that kept in freshwater systems. They seem to travel better, live longer, and are easier to maintain in a home tank. I have found absolutely no marked difference to using a marine species, they are just more expensive, harder to find, and more maintenance for your home tank. Ghost shrimp are a balanced nutrition with a shell which is concentrated nutrients including minerals and protein. while I likie to include a fish source whether it be live or dead, I have had some preds which lived many years mostly exclusively on ghost shrimp. Ghost shrimp is a good staple and inclusion in the live diet.

Guppies and mollies are actually brackish fish and they are related to the some of the same species of fish that would be consumed in the wild, like the true saltwater silversides. The fat and protein profiles are similar and after feeding many predators for a decade I believe they are safe. When people talk about fresh water feeders, the real reference is to rosies or goldfish, whether they know it or not. Both rosies and goldfish contain a high amount of thiaminese, which binds vitamin B1 and is verydetrimental. Guppies and mollies do nose would be a matter t contain thiaminese. Rosies will also bind in the gut and cause bloat, which always causes death. The fat profile of goldfish is about 10x that of guppies and mollies and contains an improper balance of omega 3 to omega 6. I can get more technical but you get the point. I do not know any other fish that has proven to safe and nutritionally sound, so don't experiment with other species unless you do your own research. While under no circumstance would I recommend feeding marine fish, introducing disease would just be a matter of time. Some have experimented with breeding their own marine fish like cardinals, but I have never seen a long term project succeed, for one reason or another. I also can't attest to the nutritional value of cardinals, just because they are a marine species, doesn't mean they are better.

 

[Gp!]

UPDATE to my analysis on the choices of live food I recommend. I get challenges to my recommendations of ghosties, guppies, and mollies. 1st off it is based off of more than 20 years of feeding dozens, over a hundred different predatory fish. This hobby is not absolute and anyone can find fault with anything, I have just determined that these are the safest choices that will provide the necessary nutrients to provide a very long life. Sometimes you just have to include live foods, whether the pred just refuses to accept live foods, or species which notoriously don't live long on a dead only diet. You have to make the "best" choices, maybe not the only choice, but the best. I strongly suggest not using feeders from marine sources, unless you are getting shrimp from a source that does not plumb their invert systems with fish. Although inverts will not be affected by fish diseases, fish diseases will hitchhike into other tanks and infest your fish. While I have been repeatedly warned about internal parasites from guppies and mollies, I have never seen it in over the 20 years I have used them. As a high recommendation, I do strongly suggest you breed your own. Today the sources of guppies and mollies are highly compromised by poor and polluted waters and heavily dosed with med cocktails.

The species of ghost shrimp that many find available are euryhaline species that kept in freshwater systems. They seem to travel better, live longer, and are easier to maintain in a home tank. I have found absolutely no marked difference to using a marine species, they are just more expensive, harder to find, and more maintenance for your home tank. Ghost shrimp are a balanced nutrition with a shell which is concentrated nutrients including minerals and protein. while I likie to include a fish source whether it be live or dead, I have had some preds which lived many years mostly exclusively on ghost shrimp. Ghost shrimp is a good staple and inclusion in the live diet.

Guppies and mollies are actually brackish fish and they are related to the some of the same species of fish that would be consumed in the wild, like the true saltwater silversides. The fat and protein profiles are similar and after feeding many predators for a decade I believe they are safe. When people talk about fresh water feeders, the real reference is to rosies or goldfish, whether they know it or not. Both rosies and goldfish contain a high amount of thiaminese, which binds vitamin B1 and is verydetrimental. Guppies and mollies do nose would be a matter t contain thiaminese. Rosies will also bind in the gut and cause bloat, which always causes death. The fat profile of goldfish is about 10x that of guppies and mollies and contains an improper balance of omega 3 to omega 6. I can get more technical but you get the point. I do not know any other fish that has proven to safe and nutritionally sound, so don't experiment with other species unless you do your own research. While under no circumstance would I recommend feeding marine fish, introducing disease would just be a matter of time. Some have experimented with breeding their own marine fish like cardinals, but I have never seen a long term project succeed, for one reason or another. I also can't attest to the nutritional value of cardinals, just because they are a marine species, doesn't mean they are better.

I was just reading about thiaminase and happened back across this list of fish with/without: http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm

I noticed it specifically mentions that Largemouth bass (Micropterus salmoides) and Blue gill (Lepomis macrochirus) do not contain thiaminase. I have an unlimited supply of these. Have you ever used these as feeders? Do you think they would be good to mix into a varied feeding routine?

 

[lion king]

I was just reading about thiaminase and happened back across this list of fish with/without: http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm

I noticed it specifically mentions that Largemouth bass (Micropterus salmoides) and Blue gill (Lepomis macrochirus) do not contain thiaminase. I have an unlimited supply of these. Have you ever used these as feeders? Do you think they would be good to mix into a varied feeding routine?

I did a quick nutritional analysis as thiaminese is not the only concern, fat profile is also important, they do contain a good amount of protein. I would be tempted to include the largemouth bass as they seem to have a decent amount of fat and high in omega 3. One problem with the wrong fats are omega 6 will be much higher than omega 3 and that causes an issue, for humans as well just for your own info. The bluegill on the other hand seems to have a high amount of saturated fats, which would cause alarm to me, I likely would not offer those. Just be reminded there is no long term history including these fish in the diet of marine predators. I know these are fresh water fish, so I'm not sure of the relationship the largemouth may have with the sea bass, but the sea bass is an excellent food. Anything to be include should always just be a part of the overall diet, and especially with an unproven food, used sparingly.