I assume you have N. wennerae. They have been reared successfully using the following method. First, however, some basic biology. The eggs take three weeks to develop and hatch. They need their mother's care, so do not remove them from her cavity. After hatching the larvae will remain with the mother in her cavity for about 6 days. During this time they will molt twice and live off their yolk. During this period they are thigmotaxic and negatively phototaxic remaining in a clump in the cavity. The third molt they become positively phototaxic and at dawn swim out of the cavity up into the water column. They are now planktonic and will not settle to the bottom for a month. They have also exhausted their yolk and need to start eating. During the planktonic phase, they will molt three or four more times and grow to about 7 mm. At this time, they molt to a postlarval stage and settle.
The technique that has worked rearing them is as follows.
1. Collect larvae the morning they become free-swimming. This is easy using a flashlight to attract them to the top or side of the aquarium. A turkey baster works well to suck them up and transfer them to containers.
2. Place one larva each into a 5-10 oz plastic cup filled with clean seawater. Start feeding with copepods, rotifers, and newly hatched brine shrimp that have been treated with supplement such as Selcon. As the larvae get larger, you can switch to larger food using bigger brine. Gut loading with Cyclopsese (never can spell it) helps.
3. This is the hard part. Each morning add the live food - about 20-50 organisms per cup. After a few hours, remove the food and change the water. I find the easiest way to do this is to suck up the larva with the baster, rinse out the cup and replace the water, then return the larva. Ideally they should have 24 hour access to food, but that is too much work for me. I feed once a day.
4. Don't try to rear multiple larvae per cup. They are cannibalistic.
5. When the larvae are about 5-6 mm long, add a thin cover of gravel to the bottom of the cup. This promotes molting to a postlarval stage and settlement.
6. Once they settle, feed Cyclopsese, amphipods, brine shrimp (small adults), etc.
Be prepared for a lot of work and frustration. The last time I did this, I started with 100 cups and successfully reared only a handful of animals.
Roy
