Lionfish nutrition study

[Jay Hemdal Verified Community Expert]

A study was just published regarding captive versus wild lionfish nutrition (specifically fatty acid profiles). I had some difficulty understanding much of the data, but the abstract and conclusion had some interesting items.

https://www.mdpi.com/2673-5636/3/3/28
@lion king @Lionfish hunter

Jay

 

[lion king]

Interesting, kind of curious how the molly is a benthic omnivore, as well as related fish like guppies. The molly has been my recommended live fish food and this may be one part to the long term success for those that choose to feed live mollies to their predators. I'm sure the high thiaminese diet is another major contributor to a short captive lifespan.

https://fishkeepingfolks.com/sailfi...olly. Origin and descriptions Species profile

 

[lion king]

Silversides is also a major part of many predator's diet, silversides is a common name for many species. Curiously the Hikari brand silversides(Pseudohemiculter dispar) that I recommend is a benthopelagic species, while many of the other brands are Osmerus mordax, a pelagic species. The Pseudohemiculter dispar also does not contain thiaminese, while the osmerus mordax does.

 

[lion king]

Some of the other issues discussed in the study may be due to overfeeding. It's sometimes difficult to get people to understand the concept of feeding their adult lions or other ambush predators no more than twice a week. They turn their predators into grazers rather than gorgers, which screws with their natural metabolism.

 

[Jay Hemdal Verified Community Expert]

Silversides is also a major part of many predator's diet, silversides is a common name for many species. Curiously the Hikari brand silversides(Pseudohemiculter dispar) that I recommend is a benthopelagic species, while many of the other brands are Osmerus mordax, a pelagic species. The Pseudohemiculter dispar also does not contain thiaminese, while the osmerus mordax does.

I've never heard of rainbow smelt, Osmerus mordax being sold as "silversides". The smallest I've ever gotten from my suppliers are about 3" long. Is there a special fishery for smaller ones?

I thought silversides were Atheriniformes, usually Menidia sp.

Jay

 

[lion king]

I've never heard of rainbow smelt, Osmerus mordax being sold as "silversides". The smallest I've ever gotten from my suppliers are about 3" long. Is there a special fishery for smaller ones?

I thought silversides were Atheriniformes, usually Menidia sp.

Jay

My understanding is the most commonly used species called silversides is the rainbow smelt. I emailed every silverside company to find which species they used, Hikari was the only one that responded with the actual species that was not rainbow smelt. V2O was very vague and would not confirm the species and when I followed up asking about rainbow smelt, they did not respond. None of the other companies would give me an answer to the actual species used. For as long as I can remember I've seen warnings about feeding silversides.

 

[Jay Hemdal Verified Community Expert]

My understanding is the most commonly used species called silversides is the rainbow smelt. I emailed every silverside company to find which species they used, Hikari was the only one that responded with the actual species that was not rainbow smelt. V2O was very vague and would not confirm the species and when I followed up asking about rainbow smelt, they did not respond. None of the other companies would give me an answer to the actual species used. For as long as I can remember I've seen warnings about feeding silversides.

That's the problem with common names. The old saying goes: not all gold fish are goldfish and not all goldfish are gold fish.

True silversides have two dorsal fins - a spiny and a soft. Smelt have a single dorsal and a tiny adipose fin behind that. All of the silversides I've seen for sale have been the true silversides (but I don't think I've seen the Hikari ones).

My understanding was always that true silversides (Atherinids) are not high in thiaminase, but true smelts (Osmerus) are.

Jay

 

[monkeyCmonkeyDo]

Good reading. Ty guys. Glad lionking chimed in as I was curious on his input.
D

 

[lion king]

That's the problem with common names. The old saying goes: not all gold fish are goldfish and not all goldfish are gold fish.

True silversides have two dorsal fins - a spiny and a soft. Smelt have a single dorsal and a tiny adipose fin behind that. All of the silversides I've seen for sale have been the true silversides (but I don't think I've seen the Hikari ones).

My understanding was always that true silversides (Atherinids) are not high in thiaminase, but true smelts (Osmerus) are.

Jay

That's a good point, I'll check out some of the other brands of silversides. I started using and recommending only Hikari, since they were the only ones to varying which species they used. At the time my only concern was thiaminese and I did know rainbow smelt was the most used, at least at the time I did my research. I believe the species of fish you are mentioning are more common in Australia, which is where you are from, right. The Atherinids you speak of also live in fresh, brackish, and marine waters; but I for sure the species we get here in the States come from fresh water lakes.

 

[Eagle_Steve]

That's a good point, I'll check out some of the other brands of silversides. I started using and recommending only Hikari, since they were the only ones to varying which species they used. At the time my only concern was thiaminese and I did know rainbow smelt was the most used, at least at the time I did my research. I believe the species of fish you are mentioning are more common in Australia, which is where you are from, right. The Atherinids you speak of also live in fresh, brackish, and marine waters; but I for sure the species we get here in the States come from fresh water lakes.

You now have me curious about this. I only feed live mollies, ghost shrimp, and hikari SS . Although I do also feed greenbacks that I catch in Fl and freeze. I am now wondering about the greenbacks….. are the good or not?

 

[lion king]

You now have me curious about this. I only feed live mollies, ghost shrimp, and hikari SS . Although I do also feed greenbacks that I catch in Fl and freeze. I am now wondering about the greenbacks….. are the good or not?

Since they are related to salmon, I'm going to go out on a limb and say they are a fine food. I also recommend those feeding dead food to include a fatty fish like salmon, trout would also suffice. I'm sure you also using them fresh or in small frozen batches, so thiaminese would likely not be an issue. I did a quick search and couldn't find out if they were a benthic species, but did find out they feed on benthic crustaceans. Since it's also included with other known good foods, I'd say good.

 

[Eagle_Steve]

Since they are related to salmon, I'm going to go out on a limb and say they are a fine food. I also recommend those feeding dead food to include a fatty fish like salmon, trout would also suffice. I'm sure you also using them fresh or in small frozen batches, so thiaminese would likely not be an issue. I did a quick search and couldn't find out if they were a benthic species, but did find out they feed on benthic crustaceans. Since it's also included with other known good foods, I'd say good.

That good to know. I have been digging as well, as we call them greenbacks, but they are a mix of small thread fin hearing and scaled sardines.

Opisthonema oglinum And Harengula Jaguana respectfully.

I do give them some fresh ones from time to time and some even make the 12 hour ride back alive lol. Don’t do that much though.

I have also thought about glass minnows as some are actually silversides and others are anchovies. I cannot tell the difference, but those also appear to be ok from what I am finding.

 

[lion king]

That good to know. I have been digging as well, as we call them greenbacks, but they are a mix of small thread fin hearing and scaled sardines.

Opisthonema oglinum And Harengula Jaguana respectfully.

I do give them some fresh ones from time to time and some even make the 12 hour ride back alive lol. Don’t do that much though.

I have also thought about glass minnows as some are actually silversides and others are anchovies. I cannot tell the difference, but those also appear to be ok from what I am finding.

Minnows do contain a good amount of thiaminese. I warn against feeding the rosies that lfs sell as feeders, because they also bind in the gut causing bloat and death. I've dissected lions with twisted guts and undigested rosies. I can't say if the minnows you catch could do the same thing. I've seen enough to know it's a big risk feeding rosies. I'm not sure if they live long enough in the gut to twist and cause a problem or there's something in the bone structure to bind.

When you said greenbacks, I was thinking of Oncorhynchus clarkii stomias. I'm not familiar with the herring or sardines but have read success in some of the Nordic Countries feeding these to lionfish. Maybe not the same specific species but related.

 

[Eagle_Steve]

Minnows do contain a good amount of thiaminese. I warn against feeding the rosies that lfs sell as feeders, because they also bind in the gut causing bloat and death. I've dissected lions with twisted guts and undigested rosies. I can't say if the minnows you catch could do the same thing. I've seen enough to know it's a big risk feeding rosies. I'm not sure if they live long enough in the gut to twist and cause a problem or there's something in the bone structure to bind.

When you said greenbacks, I was thinking of Oncorhynchus clarkii stomias. I'm not familiar with the herring or sardines but have read success in some of the Nordic Countries feeding these to lionfish. Maybe not the same specific species but related.

They are just called minnows. They are saltwater and are a mix silversides (I know these are ok) and anchovies (those I do not know if ok)

 

[Eagle_Steve]

They are just called minnows. They are saltwater and are a mix silversides (I know these are ok) and anchovies (those I do not know if ok)

Well, these types. Some do contain it and some do not. I cannot get a positive yes or no on the types found in FL, so why I never fed them.

 

[Jay Hemdal Verified Community Expert]

That's a good point, I'll check out some of the other brands of silversides. I started using and recommending only Hikari, since they were the only ones to varying which species they used. At the time my only concern was thiaminese and I did know rainbow smelt was the most used, at least at the time I did my research. I believe the species of fish you are mentioning are more common in Australia, which is where you are from, right. The Atherinids you speak of also live in fresh, brackish, and marine waters; but I for sure the species we get here in the States come from fresh water lakes.

No, I live in Michigan.
There is a freshwater silversides in the US, but it isn’t harvested for food.
Jay

 

[lion king]

Here's an article from 2017 that makes it even more confusing, I wonder if Hikari even still uses the species of fish they were using when I initially researched this more than 10 years ago. I guess I need to do some updating, my initial research did find many "silversides" used for food was from lakes.

https://reefs.com/brief-word-silversides/

 

[Eagle_Steve]

Here's an article from 2017 that makes it even more confusing, I wonder if Hikari even still uses the species of fish they were using when I initially researched this more than 10 years ago. I guess I need to do some updating, my initial research did find many "silversides" used for food was from lakes.

https://reefs.com/brief-word-silversides/

Well, makes me wonder if I should switch to San Fran bay. I have easy access to both. Although, I do not feed them much, except to my nems at this point. But still, would rather the nems eat sw fish lol.

 

[lion king]

Since one of the main points of the study was pelagic fish vs benthic, and silversides is likely the most common fish fed to predators in captivity. Regardless of the species, it may be likely for these to pelagic, so that is the consideration.

 

[Jay Hemdal Verified Community Expert]

Here's an article from 2017 that makes it even more confusing, I wonder if Hikari even still uses the species of fish they were using when I initially researched this more than 10 years ago. I guess I need to do some updating, my initial research did find many "silversides" used for food was from lakes.

https://reefs.com/brief-word-silversides/

Joe is a good taxonomist. His info is more up to date than mine (I rely on Nelson's Fishes of the World" from 2010. You can still use the dorsal fin structure and the presence/absence of an adipose fin to place the fish in basic taxonomy.

In the end, because of the confusion, I supplement all predatory fish food with thiamin and Vit. E.

The fatty acid profiles is a whole other issue though.....

Jay