Dottyback Larval Rearing-Step by Step
Since P. fridmani eggs will hatch after only 4 days the larvae will be much smaller than clownfish larvae. (Think 5mm slivers of glass with 2 shiney eyes.) The larvae need to be fed rotifers as early the next morning as possible.
Step One: Incubation Choices
While it is best to allow the male to incubate the egg mass, some males may take a while to learn how to do that. If the male has problems tending to the egg mass you can incubate the eggs artificially in an "egg tumbler". Basically a glass funnel with an airline to provide bubbles to keep the eggs moving and to avoid fungal infection. If you choose to use this method the egg mass should be dipped in a dilution of formalin to help control fungal problems.
After disinfection the eggs mass can be placed in the tumbler.
Egg Tumbler: A simple egg tumbler can be made with a glass funnel and airline tubing. I used a light reflector as a base to support the funnel. Eggs are placed in the tumbler and "tumbled" with air bubbles. It takes a bit of parctice to get the bubbles right, not to slow and not too fast. You just want to make sure that the eggs keep moving and don't get stuck.
To help keep the water warm I place the metal base on a reptile heating mat, you could also partially submerge the funnel in a tank with water and a heater.
Here is what mine looks like:
Step 2: Fourth Night
As I mentioned, the eggs should hatch on the fourth night after they were spawned. Since I'm not usually awake early enough in the morning, I've begun to add rotifers and phyto to the tumbler on the night of expected hatch so the larvae have something to feed on before I wake up. (That is why there is a slight green tint to the water in the above pics. This method has been working well for me.)
The first day after the eggs start to hatch I start transfering the larvae to the rearing tank.
This is what it looks like in action when the eggs hatch:
Once the male gets to the point where he can incubate the eggs without eating them, you can pull them on the evening of the fourth day after the spawn. The egg mass is placed in the tumbler near a bright light. Since the eggs are only tumbled for a short time there is no need for the formalin bath. I'm having great results with this method.
About an hour after transfer to the tumbler with bright light. The bright light certainly gets them to pop! Halfway through the hatch I transfered at least 400 to the larval tank.
In this vid you can see how phototaxic they are. With the air off they all swarm toward the light.