Rearing Mbuna fry parameter questions

[jcarson]

Hey MFK

In the past when I have bread mbuna I was taught to raise the temperature and superfeed.

So my temp in the growout tank is about 83 degrees and I feed about 4 times a day
They have grown very rapidly over the last couple weeks going from just released from mother to most being over a quarter of an inch and a lot of them already approaching the half inch mark.

Water parameters are still easy to maintain with my nitrates at 10-20 ppm.
Water changes are more gentle in the tank maybe a gallon or 2 once a week and I know this will change as they continue to grow and produce waste.

Using prime for water changes, safe seems like overkill with only a 20 gallon tank volume.

What are your methods for rearing fry quickly?

 

[tlindsey]

Hey MFK

In the past when I have bread mbuna I was taught to raise the temperature and superfeed.

So my temp in the growout tank is about 83 degrees and I feed about 4 times a day
They have grown very rapidly over the last couple weeks going from just released from mother to most being over a quarter of an inch and a lot of them already approaching the half inch mark.

Water parameters are still easy to maintain with my nitrates at 10-20 ppm.
Water changes are more gentle in the tank maybe a gallon or 2 once a week and I know this will change as they continue to grow and produce waste.

Using prime for water changes, safe seems like overkill with only a 20 gallon tank volume.

What are your methods for rearing fry quickly?

james99

 

[james99]

Clean water and good food. I'm not sure about the raising the temp. The higher temp should increase their metabolism, requiring more for and more water changes.

 

[RD.]

I agree, no need to raise temps, and feeding 3 times a day is plenty. In fact in some species of juvenile fish feeding too often becomes counter productive.

 

[markstrimaran]

Water temp 70 to 72
Feed 1/8" pellets, 2x day.

The center jar has fry ,still with yoke sacks.

The mini 2 gallon tank sits on top my sump, with T from the main pump. Every couple of days I stuck up any detris.

The stand tube, over flow drains into a sump chamber, it is normally fitted with a strainer.

 

[RD.]

This was the paper that I was thinking of earlier.....

https://www.researchgate.net/public...d_Body_Indices_of_Goldfish_Carrassius_auratus

While the paper is regarding goldfish, several species and optimum feed frequencies (x per day) were mentioned.

 

[punman]

markstrimaran I am not sure what type of fry you are showing there, but a temperature of 70-72 seems low for most tropical fish. Can you elaborate?

 

[markstrimaran]

Yes, they are Acie and yellow labs, few dragons bloods. They are kept at the ambient temprature of the house, for mostly logistical reasons. This is the 5th generation that have grown out and spawned in 68 to 74 degree water.

They can survive down to 55 F as my basement tank got cold a few times as my old heater broke.

My house is old and I can not sleep at night, having 900 watts of tank heaters, on a 15 amp circuit along with lights, pumps, and accessories, enouph for all four 75 gallon tanks. Adding a new circuit is not an option.

 

[duanes]

Although the average few inches of surface water temp in Lake Malawi ranges between 75 to 84"F depending on the season, the temps at depth average a constant 72'F.
I believe most aquarists keep tanks way too warm, and that Mark has a much more reasonable approach. Especially with species that come from large stable temp lakes, Lake Arenal in Costa Rica where Parachromis dovii are common, sometimes has months of seasonal temps in the mid to high 60sF.
Here in Panama water temps drop significantly at night, not approaching what might be considered warm, until almost noon.

I also believe many of the bacterial infections we see in the disease section posts, have to do with the currently popular warmer temps. Many pathogenic bacteria and fungi become much more virulent in 80+' water. Columnaris is especially virulent at temps 82'F and above.
Sure warmer temps speed growth and metabolism, but the bacterial counts and diseases conditions they create, are often not worth the trade off.
I'm also convinced that too many "large" feedings are problematic.
I feed many very small feedings throughout the day, and allow fry to graze on algae I don't discourage between feedings.

 

[RD.]

Yes, I agree with Duane, with the exception of temps for growing out fry. For mbuna I think that 70F is as extreme as 83F. Fry growth is partially dependant on water temp, as it affects their metabolism, and also their immune system. My mbuna fry have always done well with good growth at 76-78F. I have never had any bacterial infections in any of my African set ups over the years. Also, while many mbuna species tend to be more herbivorous in nature, yellow labs are most certainly not. Once past the fry stage I feed all my fish once day, and skip feeding at least one day a week. A hungry fish is a healthy fish.