Proof that soaking frozen food works

[myerst22]

I got a Rhinopias today and am very excited. Pics below. The survival of this fish over a long period of time by any keeper that I have heard has been 2 years at the most. So I wonder if any of those supplements, (i.e selcon, garlic etc.) are actually being absorbed by the frozen foods we add them to? I personally can't see a viable amount of lets say selcon being absorbed by a thawed out silverside. When feeding predatory fish we're always told to stay away from live foods (parasites etc). Maybe that's where we are going wrong when feeding marine predatory fish, and not feeding live foods. If we feed live food to our predatory fish and have fed "food" with high quality nutrition; then this will undoubtedly be passed onto the fish that is being fed. Sorry for being long winded. So any proof that frozen food actually "soak up" all these expensive supplements? Regards Tim

 

[Snowboarda42]

Wow I thought I was up late lol.


Personally, I think it can't hurt. There's got to be some sort of way that the Selcon gets absorbed in the food. If anything, the fish always come up to the net and get the food while its in the "cloud" of food and selcon that gets dropped in my tank. So they're getting a little at the very least, and it makes me feel a little better.

Since you're feeding a bit bigger food, consider getting a syringe, and injecting the silverside that you're going to feed the Rhinopias with Selcon right before you actually feed it. It will sort of "gut load" the silverside.

As far as proof/documentation goes, I know of none. Most advice on these boards comes from other people's experiences and hearsay from other aquarium owners. How you choose to take thus said advice is up to you.

 

[Snowboarda42]

BTW, awesome fish!

 

[Anonymous]

I can tell you that Selcon is used extensively by the staff aquarists/biologists at the Long Beach Aquarium of the Pacific. It is not diluted, and is applied to foods that have been properly thawed (they utilize human, food grade foods only kept in conditions dictated by state and federal regulations for human consumption).

I think that injecting the silverside (you might want to consider including other foodstuffs in this so as to ensure a good variety of diet) is an excellent idea.

 

[jhemdal1]

Tim,

Soaking foods has long been a source of contreversy. Until somebody runs nutritional studies, it is unlikely to be answered accurately. We did have a nutrition analyst work out uptake rates for food soaked in thiamin and vitamin E - but how fast this rinsed off once the food hit the tank was never measured.
Regarding Rhinopias longevity - I keep hearing that "two year" mark and it sure jibes with what I think I've seen, but I checked my records just now to see for sure and we've had quite a few live two+ years, and one lived three years and 8 months...still not what I suspect their natural livespans would be. The only ones we've had live less than two years died from environmental issues that we then resolved. BTW: we never keep Rhinopias in mixed-species tanks, always just them by themselves. Makes me nervous to see all those fish that might out compete it for food....

Seamaiden, you wrote: "I can tell you that Selcon is used extensively by the staff aquarists/biologists at the Long Beach Aquarium of the Pacific" - I bet you meant they are using Selco. Different product.


Jay Hemdal

 

[Anonymous]

Maybe I misread, I'd have to contact my former super on that. Smelly yellowish liquid?

 

[jhemdal1]

Selco (and Super Selco) contains HUFAs and is a smelly thick orange/yellow liquid that needs to be kept refrigerated and has a shelf life after you open it of around 12 weeks. It is made by INVE and is vacum packed in nitrogen. Most public aquariums use this. SELCO stands for: Self-Emulsifying Lipid Concentrate

Selcon is a non-refrigerated, more watery liquid that is reported to contain HUFAs, but since a mechanism to keep pure HUFAs from turning rancid without refrigeration seems to be unknown,(Or INVE would be using it!) it is suspected that this product is more of a vitamin mix. I was originally told that Selcon was re-packaged from Selco but this does not seem to be true. Most (if not all) hobbyists use Selcon because there is no way anyone is going to open a $80 packet of Selco and then throw out the 95% they didn't use after 12 weeks....public aquariums use more of it, so they tend to use it up before it goes rancid.

Jay

 

[Anonymous]

Well, I sure do remember the smell, that's for sure! :lol:

That being said, I wonder if it might act as a brine does, or if it could act as a brine does (we do a lot of brining of fowl before cooking here at home). If that were the case, then we could be fairly assured that the product would be taken up into the tissues/flesh/cells of a given feed, not to be washed off incidentally upon feeding. That said, brines are different in many ways from nutritional supplements, and in at least one important way -- no brines ever use fats (lipids), and as far as I know you can't get fats to be absorbed into feeds merely by soaking as one would in brine.

I'll have to ask my mother (R.D./food scientist) about that one.

 

[myerst22]

Thank you everyone for your input, especially Jhem. Jhem your input was very informative. As far as competition for food with the rhino's other tankmates. All the other inhabitants are fed frozen till satisfied. The rhino is then fed damsels which I put in a net and keep it contained until he takes the fare.

I have read different opinions regarding supplements, especially pertaining to scorpions whether true or false. First is that scorpions don't digest fats and will eventually cause liver failure, which has been seen in necropsies of 3+ year old lions who have dies in captivity. If this is true than soaking foods in HUFAS would be out of the question. Second. Most ambuse predators when caught in the wild have empty stomachs. This would leave me to think that overfeeding could be an issue. So as of now I'm going to feed well nurished damsels to the Rhinopias 3 times a week and only to the point where the stomach is slightly raised above the overall body. Any reaction or continued input is greatly appreciated!! Some new pics of the Rhino and one of a cool shot of my melatremus.
Regards, Tim

 

[Anonymous]

Thank you everyone for your input, especially Jhem. Jhem your input was very informative. As far as competition for food with the rhino's other tankmates. All the other inhabitants are fed frozen till satisfied. The rhino is then fed damsels which I put in a net and keep it contained until he takes the fare.

I have read different opinions regarding supplements, especially pertaining to scorpions whether true or false. First is that scorpions don't digest fats and will eventually cause liver failure, which has been seen in necropsies of 3+ year old lions who have dies in captivity. If this is true than soaking foods in HUFAS would be out of the question. Second. Most ambuse predators when caught in the wild have empty stomachs. This would leave me to think that overfeeding could be an issue. So as of now I'm going to feed well nurished damsels to the Rhinopias 3 times a week and only to the point where the stomach is slightly raised above the overall body. Any reaction or continued input is greatly appreciated!! Some new pics of the Rhino and one of a cool shot of my melatremus.
Regards, Tim

Tim, are you sure that it's that they don't digest any fats (lipids) at all, or is it particular to the types of lipids? I have been under the impression that the issue is with the lipid types. I can't imagine how they would feed normally and get no fatty acids/lipids at all, as at least the livers of the vertebrates they consume might be assumed to have some fats.

I think they're all pretty much an ambush-type predator (generalizing here). They may have empty stomachs for a number of reasons, but my first question is how this might be determined. Are they flushed for stomach content assessment, or what? How do we know that they don't do as many other animals (snakes come to mind) and regurgitate when stressed? That could account for an empty stomach. Overfeeding absolutely could be an issue, but in my own opinion it has more to do with variety of foods, as well as what those animals consumed have been feeding on themselves. If your goal is to mimic nature, then the fish will not be limited to eating one type of fish or food, and it gets it as it can. That may be daily, or it may go a few days.

I would be VERY careful to feed the fish something like live damsels, my primary concern being introduction of parasites or other unwanted organisms. Of course, this is just my opinion.

 

[Anonymous]

I agree that feeding live damsels is a very risky move, unless you're quarantining and treating them in large groups beforehand.

You should be able to train your Rhinopias on to frozen meat pretty quickly with a feeding stick. You can start with live freshwater ghost shrimp or guppies to train the Rhinopias to associate the stick with food. Be patient and eventually it will strike at dead food. You can then inject prawn meat with whatever vitamin/HUFA supplement you decide is approriate.