Why feed BBS prior to using them as larvae food? I fail to see any valid logic there.
You are not actual feeding the napuli anyway. They do not feed until after the second instar, near the end of the ideal target age for use as caudate larvae food at maximum nutritional value and size for newly hatched caudates..
As the time between hatching from the cysts and the first molt into the second instar is roughly 16 hours dependent on species/strain, temperature and photoperiod ideally one would want to time their artemia hatching accordingly by starting a new hatch every other day. By that time metabolite waste in the water will significantly decrease overall yield, and the napuli are of slightly lower nutritional value as they have burned up all of their stored DHA.
Couple this information with the fact most caudate larvae do not feed for the first 72 hours as they are utilizing "yolk" reserves while allowing their lower digestive system to finish forming in preparation for feeding.
While I have no data to prove it, I feel safe in betting that high rates of larval mortality in the first week after hatching are directly linked to feeding either too large or too much artemia napuli at the wrong time resulting in crazy fast sifts in water quality.
There is a plethora of valid and invalid data on Brine shrimp on the web as this is a common aquaculture staple and scientific model.
To help you in learning more here are some keywords and their basic definitions to help you sort out the bull-dookie from the gold:
Hint, dont use BBS in your search. It is a commonly used misnomer that often leads to invalid data!
Brine shrimp, are properly known as Artemia salina, though even this is a bit off as molecular biology is showing a vast range of diversity. Sometimes they are called fairy shrimp too, though more often I see this term used for their fresh and alkalai counterparts.
napuli- the proper term for early instar arthropods
instar- the time between each molting
molting- shedding of the exoskeleton for a bigger one due to growth more properly called ecdysis
I wish you luck! Be careful when researching these guys though....or you suddenly find you have mason jars and fish bowls filled with other "instant" arthropods.
And then your wife threatens to leave you if she finds one more glass baking dish filled with cladocerans around the house...
I should also add that there is no reason to dump napuli hatches once they get too big for your larvae. You can go ahead and feed them, or better yet, do as I do and ignore the culture save to replace evaporation with distilled water. I have one culture here that is four years old and always has multiple instars and adults swimming around in it. It is really handy to steal some of the adults out of there to feed to larger larvae and adult caudates. It is nothing fancy, just a five gallon bucket in the corner of my critter room.
