What fish fry often incidentally survive in tanks?

eschaton

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Hey all,

I'm aware that - in order to have high numbers of surviving offspring - generally speaking one has to resort to specialized tanks for breeding, or at least grow-out of the fry, and pay particular attention to having live food cultures available of the proper size before metamorphosis. Honestly the level of success that breeders have had with this is stunning, when you consider in the wild it must be the case that even if fish broadcast spawn tens of thousands of eggs, on average each mated pair must have only two offspring which reach adulthood and reproduce themselves.

I'm really not so much interested in breeding for fun and profit at this time. But I am interested, for my next tank, in trying to set up as diverse and mature of a tank as possible, which can generate as many forms of "natural food" for the tank livestock as possible. This likely means letting my display tank mature for a long time with high-quality live rock and a deep sand bed, and stocking in a very minimal manner, so when I do get to adding fish, they can get by with limited supplemental feedings.

I'm curious about what fish can - presuming they avoid getting eaten by other tank residents - survive in low numbers from hatch to metamorphosis within a main tank system - if not in the display tank, then in the sump or fuge, away from munching mouths. It seems this is pretty much limited to saltwater-conditioned Sailfin Mollies and the occasional Banggai Cardinal, but if there are other examples I'm all ears.
 
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I think the biggest issue you'll run into besides predation is having food available for the fry. Most tanks just don't have the necessary foods available. Bangaii cardinals are about the only ones I can think of that MIGHT make it.
 

Halal Hotdog

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Hey all,

I'm aware that - in order to have high numbers of surviving offspring - generally speaking one has to resort to specialized tanks for breeding, or at least grow-out of the fry, and pay particular attention to having live food cultures available of the proper size before metamorphosis. Honestly the level of success that breeders have had with this is stunning, when you consider in the wild it must be the case that even if fish broadcast spawn tens of thousands of eggs, on average each mated pair must have only two offspring which reach adulthood and reproduce themselves.

I'm really not so much interested in breeding for fun and profit at this time. But I am interested, for my next tank, in trying to set up as diverse and mature of a tank as possible, which can generate as many forms of "natural food" for the tank livestock as possible. This likely means letting my display tank mature for a long time with high-quality live rock and a deep sand bed, and stocking in a very minimal manner, so when I do get to adding fish, they can get by with limited supplemental feedings.

I'm curious about what fish can - presuming they avoid getting eaten by other tank residents - survive in low numbers from hatch to metamorphosis within a main tank system - if not in the display tank, then in the sump or fuge, away from munching mouths. It seems this is pretty much limited to saltwater-conditioned Sailfin Mollies and the occasional Banggai Cardinal, but if there are other examples I'm all ears.
Love the idea of live natural food source. I don't believe any fry would make it in our tanks. From lack of food to high flow, protein skimmer and mechanical filtration, there are quite a few things against them. I imagine you might be able to partition a portion of your sump to have low flow and one way access to the return pump. You can add food in that area based on when eggs were laid. Love the idea but can't think of a practical way to make it work.

On a side note, was watching one of the MACNA speeches and he started it with showing a predator tank being fed small clownfish that were meant to be culled. What a great use of nonviable fish.
 
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eschaton

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Love the idea of live natural food source. I don't believe any fry would make it in our tanks. From lack of food to high flow, protein skimmer and mechanical filtration, there are quite a few things against them. I imagine you might be able to partition a portion of your sump to have low flow and one way access to the return pump. You can add food in that area based on when eggs were laid. Love the idea but can't think of a practical way to make it work.

On a side note, was watching one of the MACNA speeches and he started it with showing a predator tank being fed small clownfish that were meant to be culled. What a great use of nonviable fish.
Thanks for the input.

On my older tank, I had an HOB refugium. Still have the box, although the return cracked off, so I'm not sure I'm going to use it on the new tank. Regardless, while it was mostly a chaeto reactor, it had a thriving mini-ecosystem, with tons of copepods, amphipods, mysis, etc.

I'd have to think that if this microfauna could avoid getting whooshed back into the main tank, some fry would be able to as well. Also, there isn't a tremendous difference in terms of size between copepods and BBS - and I'm guessing a well-developed fuge would have all sorts of smaller microfauna that we can't see that fry can eat.

On the other hand, fry are so small and fragile that the average fuge probably has things that can predate on them, albeit not as adeptly as fish and LPS coral in the main tank. Mysis probably couldn't take a living fry down, but I have to assume that a bristleworm or small brittle star (both of which tended to be common in my fuges) could. And simply navigating through the thicket of macroalgae would probably be hard for planktonic fry suited to open water. And food clearly isn't in heavy enough concentrations in a standard-sized fuge to support a decent-sized clutch of fry. But is it enough to have a small handful survive until metamorphosis? That's what I'm getting at.
 

8ptspike

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Hey all,

I'm aware that - in order to have high numbers of surviving offspring - generally speaking one has to resort to specialized tanks for breeding, or at least grow-out of the fry, and pay particular attention to having live food cultures available of the proper size before metamorphosis. Honestly the level of success that breeders have had with this is stunning, when you consider in the wild it must be the case that even if fish broadcast spawn tens of thousands of eggs, on average each mated pair must have only two offspring which reach adulthood and reproduce themselves.

I'm really not so much interested in breeding for fun and profit at this time. But I am interested, for my next tank, in trying to set up as diverse and mature of a tank as possible, which can generate as many forms of "natural food" for the tank livestock as possible. This likely means letting my display tank mature for a long time with high-quality live rock and a deep sand bed, and stocking in a very minimal manner, so when I do get to adding fish, they can get by with limited supplemental feedings.

I'm curious about what fish can - presuming they avoid getting eaten by other tank residents - survive in low numbers from hatch to metamorphosis within a main tank system - if not in the display tank, then in the sump or fuge, away from munching mouths. It seems this is pretty much limited to saltwater-conditioned Sailfin Mollies and the occasional Banggai Cardinal, but if there are other examples I'm all ears.
I had Banggai cardinals breed a year ago. I managed to save five fry who made it thru the night.
4 months later I discover one in my refugium. It’s a thick forest of caulerpa with tons of different pods. She managed to survive all that time on her own with a healthy diet of pods and whatever else is in there. She was the healthiest out of all of them. My next batch I think I am putting some in there and forgetting about them for 6 months. It’s sure easier than hatching brine shrimp non stop.
 

Dempsey941

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I had Banggai cardinals breed a year ago. I managed to save five fry who made it thru the night.
4 months later I discover one in my refugium. It’s a thick forest of caulerpa with tons of different pods. She managed to survive all that time on her own with a healthy diet of pods and whatever else is in there. She was the healthiest out of all of them. My next batch I think I am putting some in there and forgetting about them for 6 months. It’s sure easier than hatching brine shrimp non stop.
This.
 

Gareth elliott

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Getting fry to survive predation can be a tall order, Even in fw. In my 1000gal pond ny gold fish spawn thousands of young each year. Occasionally I get 1 or 2 that survive to size that will make it on its own. This is a very large system with many places to hide and food is not a limiting factor as there are insect larvae always available.

Only forget it and leave it spawners i have kept are live bearers and cichlids. All other fish its an effort to get fry on any reliable time frame.
 

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