High first night mortality in Ocellaris

[Francisco Andrade]

Hi everyone,

The larvae do hatch correctly, but by the early morning when I start feeding most of them are lying dead on the bottom of the tank . Afterwards, 90% of the remaing larvae survive till juveniles. I do think the broodstock diet is adequate, they are fed with a gelatin mix of salmon, squid, shrimp, lobster, crab, clam and Ulva algae, plus fish roe and Tetra Spirulina.

What can I do to increase survival ??

Thanks for any help.
Chico

 

[Acro-Head]

Francisco Andrade
I think you have either a nutritional problem with the parents (the reason I say is that of your larva are starting to die by the first moring then they have either used up their yolksac or are possible suffocating due to poor air exhange) the diet of the adults sound nutritional, but may be lacking some of the key elements that a prepared diet may contain, like extra fat for energy)
There is another post about eggs not being colored when layed or dissappearing after a day or two.
By the sound of that I would defintely say nutrition is a main focus to stress. You may have a good balanced diet, but the other thing is the quantity you feed. You really need to keep mom nice and fat. If she eats then she is usually hungry.
Just my two cents
Hope it helps

 

[Dman]

Another possibility, one that I've had problems with, is with the aeration. If it's too strong the current it produces will suck in the fry and slam them to the surface.
There's two ways that I've used to solve this, I turn off the airstone the night of the hatch and I feed, feed, feed the parents. My broodstock is fed three times a day which keeps them really fat and happy and the larvae they produce are usually strong enough to resist the pull of the airstone's current.
HTH
Dman

 

[Francisco Andrade]

Hi,
How long have your fish been spawning?
My problems started after two years of frequent spawning. At one point the eggs were pale and disapeared three days after laid, since I added roe and a better gelatin mix, the eggs got some color and started hatching, but a high mortality have been occuring the first night. I tried to boost the pigments and HUFA profile of the broodstock diet, let´s see what happens next friday.
chico

 

[Dman]

Francisco Andrade,
I didn't realize that they had been spawning for that long. I would think that that would bring with it a new set of circumstances.
It sounds like you make your own food, here's what I would try, it's a shot in the dark from my end, but I can't see how it would hurt.
Vary the food intake.
That's an impressive list of ingredients, split them in half. For example make one batch of food containing, slamon, squid, algae, roe and the Tetra Spirulina and another batch with the shrimp, lobster, clam and add freeze dried Cyclop-Eeze.
Feed one in the morning and the other in the afternoon. Then after a week, switch. Next batch of food, different combinaton of ingredients and so on.
MTCW
Dman

 

[Francisco Andrade]

Dman,
Cyclop-eeze has a very high pigment content. And this is widly known to improove spawnings.But I live in Brazil and this is not available around here. One fellow aquarist, LouisZ, found an interesting article aboutusing paprika esters in order to supply these pigments. I got the article, andit seems that paprika esters are better even than astaxanthin esters. I also added some fish oil to boost the HUFA content of my mix. One batch hatched last night, so next friday we should have one more spawn. Let's see what comes.
Chico

 

[Dman]

Chico,
Keep us posted.
Dman

 

[Francisco Andrade]

Dman,
They have just spawned. It seems the eggs do have a better coloration, let´s see how the larvae will do. Anyway, last hatch is doing fine with 100plus fish metamorphosed. My calculations is that this represent 63% overall survival.
Chico

 

[Dman]

Chico,
That's great, I wish my survival rate was as high (I'm working on it). Did you manage to find paprika esters? And from what I've read, fish oils are one of the best ways to boost HUFA's in the broodstock diet.
What are you using for a first food?
Dman

 

[Francisco Andrade]

Hi Dman,
As written in the article I told you, I added 20 g of paprika powder per kilogram of mix, this should yield about 30mg paprika esters per kilogram of food. The first food is the standard rotifers (brachionus) cultured with microalgae (nannochloris). At they four I start feeding artemia nauplii (GSL strain, althought San Francisco would be better). I think I will have 130-150 from the current hatch.
Chico

 

[Francisco Andrade]

Hi Dman,
As written in the article I told you, I added 20 g of paprika powder per kilogram of mix, this should yield about 30mg paprika esters per kilogram of food. The first food is the standard rotifers (brachionus) cultured with microalgae (nannochloris). At they four I start feeding artemia nauplii (GSL strain, althought San Francisco would be better). I think I will have 130-150 from the current hatch.
Chico

 

[Dman]

No way to get Cyclop-eeze down there? Makes a pretty good second food. Just out of curiosity, how big is the average spawn on the Ocellarus?
Dman

 

[Francisco Andrade]

Hi Dman,
No way to find cyclop-eeze around here, probably by early may I should travel to Miami, so I will buy some. My spawning are around 180-200 eggs, with 99% hatch rate.
Chico