low survival rate of clown larvae-any ideas?

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lizardlady58

Guest
My percula and maroon clowns have been breeding on a regular basis for quite awhile now, but for some reason, I never seem to be able to raise more then six to ten babies per brood. the broodstock get fed three to four times a day with frozen food consisting of brine shrimp, bloodworms, reef green, shrimp and marine fish meat. Also once a week they get squid and one feeding of hufa soaked high quality flake food. The fry usually hatch out a bit thin, most die within three days. My light is about seven feet up from the tanks, (I put the eggs in ten gallon tanks with about three gallons of parent tank water initially) the tanks are covered on all sides with black mac tac and the bottoms are white. I lower the salinity by dripping fresh water into the tanks the day after hatching to bring it to 18. The temp is 80 and I feed rotifers three to four times daily, the rotifers are fed nano. algae paste (diluted of course). I add a teaspoon of this diluted algae past mixed with water to the tanks the day of hatching to bring the water to a light green shade and continue to add a bit every night before lights out. I use minimal air movement and the rotifers usually multiply in the larvael tanks. The ammonia is usually very low. I use ammonnia badges to keep an eye on the levels. I change 20 to 50 percent of the water daily as needed as well as siphoning the bottom daily. I leave the lights on for 14 hours a day and the larvae swim around normally so I don't think lighting is an issue. I am wondering if the parents are missing something in their diet. they produce a lot of eggs, could I be feeding them too much? Any suggestions would be appreciated. thank you
 
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lizardlady58

Guest
thank you for the tip, the coral vital may help. I forgot to mention that I powerfeed my rotifers with hufas and nanochloropsis eight hours before I feed to the babies and I also powerfeed the artemia with hufas once they are a few days old.
 

bang guy

Moderator
Do all of the eggs hatch?
Is there a preservative in the algae paste? (What brand are you using?)
What kind of light are you using?
At what age are you introducing the Artemia nauplii?
 
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lizardlady58

Guest
I take the eggs late in the afternoon that they are due to hatch, I do take them out of the water momentarily to transport them to the fry tank. I have noticed that the eggs, especially lately hatch a day later then they would if I left them in their parent tanks. Even then, usually about half the babies hatch and then the rest hatch the following night. .I am using rotigrow nano, from reed mariculture. It comes in frozen slabs and I take pieces off as I need them. The stuff is quite concentrated so a teaspoon in a 8 ounce bottle cooled boiled water lasts about a week. I am using two fourty eight inch vitalites that are set about five feet above the tanks. I introduce the artemia around the third day.
 

bang guy

Moderator
Just a few things that I would do, right or wrong. They may make no difference but it's worth an experiment if you're having trouble.
First is harvesting. Try harvesting them earlier in the day. Then place the eggs high in the tank. My best success is when the eggs are only 1/4" below the water surface. There's more O2 there and the surface agitation closely mimics the parents fanning. Make sure there is absolutely NO light anywhere on the night of hatching. They do best in pitch black in my experience.
Next is lighting. Your lighting is probably fine but I prefer a point source because I believe it makes the shadows look more natural. A 20 watt halogen over each tank would create a more natural look for the rotifers and might make them easier targets.
Last suggestion is the Artemia. IMO day 3 it too early. If they grab an Artemia and have to fight with it for a while to eat it then they have expended more energy than they need to. I would wait for day 5 to start Artemia. For the first few days I would only use freshly hatched Artemia, nothing older than 24 hours. Newly hatched Artemia larve are not nutritionally complete but at that age the larvae will also be eating Rotifers.
Also for the Artemia, only use the "Premium" or "Gold" , whatever is the highest quality of eggs. The lower quality eggs are lower in nutrients and higher in contaminants.
They also need some waterflow for exercise. My best results are with a circular pan with constant circular water flow where the Larvae need to swim constantly on the edges but can rest in the middle if need be.
 

teresaq

Active Member
i dont want to interup your thread, but Bang, have you ever used
Decapsulated Artemia Cysts GSL strain

This is what i hatch for my baby seahorses. No shells.
T
 

bang guy

Moderator
I have decapsulated Artemia on my own just using bleach. It's convenient in that the hatch rate is a lot higher and there are no shells.
 
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