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Panda larvae deaths

Posted: 16 Feb 2006, 00:25
by tjudy
I have been collecting and hatching C. panda eggs for a couple weeks now, but all of them have dies a few days after hatching. I have tried leaving them in the containers I am hatching them in, and placing them in a grow out show box. How do you go about rearing larvae to free swimming?

Posted: 16 Feb 2006, 04:59
by housewren
I am no expert, but I do have over 60 panda fry from my 3 females, ranging in age from just hatched to almost 2 months old and have only lost 2 in the process so far. Some things that need to be considered are:

How you are feeding the fry, how many fry and how big of a container you have them in, how often and how much water you change, the water parameters (pH, temperature, etc.) in your container compared to the water that you add for water changes.

Here's what I have been doing. I hatch my eggs in small plastic containers floated in the aquarium. When the eggs start hatching I add a bit of java moss to the container (I don't rinse the moss out because I want all the little organisms to be attached to provide microscopic first food for the fry), and then I start feeding microworms to the fry 2 days after hatching.

I leave them in the hatching container with the newer unhatched eggs for several days before moving them to a larger container, also floated in the aquarium. Currently, those older than two weeks are all together in a critter carrier. All containers get a 90-100% water change once (or twice a day, depending on how dirty they are) with the change water coming from the aquarium where the eggs were laid. (They will be moved to their own aquarium with a filter soon so that the water changes won't be quite so critical. Also they are getting to the size they need a little more space). I do not use those hang in the tank nets because I think the fry would starve--the microworms would go right through the mesh of the net and the fry would not be able to get to them.

After a couple of weeks, I start giving an occassional feeding of pulverized flake food, and I remove any left over food with a turkey baster after a couple of hours.

Hope that helps some

Cheri

Posted: 16 Feb 2006, 16:38
by tjudy
THanks Cheri.

Mine are dying before the are eating. They are not gettign to the free swimming stage.

Posted: 16 Feb 2006, 17:01
by housewren
Another possibility I have just thought of--where did you get your pandas from? They may be very highly inbred, especially if they were produced by a hobbyist. If a hobbyist got the fish originally from a club auction, they were probably siblings. He bred them and distributed the offspring to other hobbyists and LFS's. Another hobbyist comes along, gets a bunch of these siblings, raises them and breeds them, and the pattern continues--multiple generations of sibling matings. Inbreeding often leads to high fry mortality.

Of course, I you purchased them from an LFS, it may be hard to find out what their ancestory is.

I am currently looking to replace all my males with fresh stock from out of my local area, even though I don't have high mortality or deformities. I just want to prevent it from happening.

Perhaps someone with more experience will chime in here with some helpful information.

Cheri

Posted: 16 Feb 2006, 22:25
by Kana3
Tjudi:
How long from hatching do you begin feeding?
What are you feeding?
How much?

Do you have adequate water circulation?
What is the temperature?

Posted: 17 Feb 2006, 03:52
by tjudy
Not feeding yet... yolk sacs are less than 1/2 absorbed when they die.

Posted: 17 Feb 2006, 05:42
by skids
I currently hosting my first 4 eggs in a plastic floating container, 7 days now no hatch , but it looked at first I saw an embryo inside.

Could you perhaps post the water parameters for what worked (housewren) and what didn't (tjudy) ?

kH, gH, temp, NO3, NO2, pH, TDS if you have a meter

Posted: 17 Feb 2006, 15:01
by housewren
skids,

I understand pH can be very important in hatching cory eggs. If it is too high (my guess is above 7.8 ) the "shells" become to hard and the fry cannot escape.

My breeding tank, which I use for water changes in the egg and fry containers has the following parameters:

temp = 70 F
pH = 7.0
dGH = 5, which I think works out to be about 90 ppm
ammmonia = 0 ppm
nitrate = 10 ppm

I checked my "dirtiest" fry container just before changing its water
ammonia = 0 ppm
nitrate = 20 ppm, this is higher than I like, so I am adding more java moss to the container.

Because my water is so hard and alkaline (pH > 8.4, dGH = 18 ), I collect rainwater and snow melt and mix it 2:1, rainwater:tap water, to bring it into line for my breeding tank. The way I did it at first was to cover the bottom of the aquarium with dead oak leaves--that worked, too, to get them to breed, but it made a mulmy mess, and I could never find the eggs to rescue them--just every once in a while I would see a few week old fry.

Hope you have better success next time (I would think they should still be breeding on a fairly regular basis--mine are anyhow).

Cheri

Posted: 18 Feb 2006, 00:10
by tjudy
pH 6.8 - 7.0
KH 2-3
conductivity 160 mS (80 ppm TDS)
dish temp 74-75F (room temp in my fishroom)

I have some eggs that have hatched in the shoe box that I had planned to grow the fry out in. We will see if they make it longer. One difference is that there is no meth. blue in the shoe box, but there is in the hatching dish.

Posted: 19 Feb 2006, 18:53
by FelineFishGuy
As i am at my max with tanks i have raised many pandas by placing collected eggs (usually on plant leaves or breeding mop yarn)in a net breeder with a very small sponge filter and some floating plants right in a very stable main tank. Several days after the eggs hatch i sprinkle in crushed flake or pellets - they do just fine on that.

I never use meth blue and I have never had panda eggs fungus in my water (pH 7.5 and moderate hardness. I think the youngins are susceptible to nitrates above 20ppm - much more so than aeneus corys. Suggest excellent circulation in the hatching vessel and early fry vessel and lots of water changes if the hatchery is not connected to a stable water body.

Regards and good luck
FFG