Egg yolk as fry food.

[esoxlucius]

There is a thread on the go right now titled, "hints for grinding up pellet food for fry". Part way through ground up egg yolk was mentioned. I was going to make an observation in that very thread regarding egg yolk but thought it maybe deserved its own thread, so here goes.

I've never fed powdered egg yolk, which seems to be a popular food for fry. Simply because I don't breed fish so i've never needed to feed it.

What I don't understand is that we are led to believe that certain foods are not particularly good for fish, even though they are popular. I'm talking beef heart and terrestrial based plant foods such as peas or broccoli etc etc.

I get that beef heart and terrestrial based plant foods are not particularly good, I mean when would a fish in the wild ever come across these foods?

So....egg yolk!!! WTF!!

And what gets me even more is that it seems to be a go to food for the most vulnerable and needy of fish...fry!!

What is it about dried, ground up cooked egg yolk? It seems, along with beefheart and terrestrial based plant foods, a most unlikely food to feed to fish?

 

[FJB]

All Iva say is try egg yolk for small fry of egg laying fish. It works really well, it is inexpensive, and available anywhere. Just to be clear, I am referring to hard boiled egg yolk, just a small amount disolved in one’s fingers. No, they will not find it nature, but neither will they find Tetris or NLS. Try and report back.

 

[Backfromthedead]

I was thinking along these lines as i read the other thread. Egg yolk is notoriously high in cholesterol...is that really something we should be feeding fish at a critical developmental stage?

But hey, seems to work for those in the know. I dont breed fish so what do i know. I suppose caviar is pretty high in cholesterol too so maybe the cholesterol is why this trick works so well.

 

[RD.]

Old school method from before the days of when more balanced nutrition could be easily sourced from the internet.
oh right, there was no internet back then …….

 

[jjohnwm]

Back in the day I used this a fair bit. The accepted method back then was to hardboil the egg, place the yolk into a handkerchief or nylon stocking, and squeeze a cloud of nearly-microscopic particles into the water. Great stuff; if you listened closely you could practically hear your tank water getting foul. It was mostly reserved for extremely small-sized fry that could not immediately handle freshly-hatched brine shrimp. This was sort of your emergency food if your infusoria or green-water culture crapped out on you.

Its nutritional value is obviously questionable, but it would only be used for the very first few days after fry hatching, after which they would be big enough for baby brine shrimp. Don't forget: people were feeding beef heart to discus and ant "eggs" (pupae) to turtles, and thought they were on the cutting edge of animal nutrition. Times change.

Don't you dare roll your eyes, Esox...you have a wormery, for crying out loud...

 

[phreeflow]

Had a friend who bred lots of discus and he’d put the fry in a floating stainless steel bowl and rub egg yolk on the inner edge of the bowl so the fry could pick at it constantly. Worked great him.

However, whenever I tried it in my fry tanks, it would foul the water and cause a bacterial infection and they'd all get whirling disease and belly crawl and die. I’m sticking with bbs

 

[esoxlucius]

Don't you dare roll your eyes, Esox...you have a wormery, for crying out loud...

My wormery, worm heap, compost heap, bio recycling bin, whatever, is one of the most practical and rewarding aspects of the hobby, for me.

Recycling the waste to prevent it going to landfill is one thing, the resulting masses of worms is an added bonus, given I'm into fishkeeping and angling. And then right at the end I have the nutrient rich compost to surface dress my plants with. Win win win.

My wormery is just as important to me as my little crappy Chinese plastic surface skimmer....which, by the way, hasn't set the house on fire yet! Lol.

 

[Friller2009]

I use it for rainbow fry.
The powdered stuff is like crack.

 

[jjohnwm]

My wormery, worm heap, compost heap, bio recycling bin, whatever, is one of the most practical and rewarding aspects of the hobby, for me.

Recycling the waste to prevent it going to landfill is one thing, the resulting masses of worms is an added bonus, given I'm into fishkeeping and angling. And then right at the end I have the nutrient rich compost to surface dress my plants with. Win win win.

My wormery is just as important to me as my little crappy Chinese plastic surface skimmer....which, by the way, hasn't set the house on fire yet! Lol.

Just to be clear, I am not in any way laughing at the basic idea; I always have a compost heap on the go, and back in Ontario it was large enough, the climate was warm enough and the native worm population was plentiful enough that my compost heap was a reliable source for them all year round. It generated enough heap on its own to stay unfrozen and it was easy to use a spading fork even in the dead of winter and quickly find a dozen big nightcrawlers. Worms are pretty scarce in my current locale, and never get really big, so it's less productive here.

But having one isn't what I find funny; it's calling it a "wormery" that I get a chuckle out of...

 

[duanes]

I had one in the states, I called it a composite heap.

There are certain fish species that have adapted to eating mostly terrestrial plants, so doing a little research is sometimes useful.
The species in the genus Cincelichthys and Etroplus suratensus have made an art of using terrestrial leaves, and fruits, and developed extended digestive tracts for making use of the scant nutrients they provide.
Many Vieja are frugivores, so eat fruit, figs, and waterlogged seeds. Same goes for pacu that are considered major seed distributors in S America.
There are even salt water species that make use of terrestrial plants.


I watched the marine species in the pic on the right, come to that same tree every morning for weeks on end to graze on overhanging leaves in a brackish lagoon in the Yucatan.