Emerald Crab

So my emerald crab is releasing larva every two weeks.  I have been collecting the larva and my best to date is 10 days post release.  I have tried rotifers, nhbbs, nanno and tetra.  I noticed, by looking through a magnifying glass, that there where two different sizes. The smaller ones where still alive, the larger ones where dead and completely white.  Are they hitting a certain stage and dying on me or is it possible that what im seeing is what they have shed? today would be day 5 and its the first day for this batch that I noticed it.  If anybody has any ideas or an educated guess I would appreciate it. Thanks, Greg

Do you have access to a microscope to stage them at all?  Around day 3-4 they are ideally molting into Zoea II, so perhaps what you are seeing at day 5 are old molts...but it's all guesswork unless you can get a good look at them.  All the papers I have read about rearing Mithrax/Mithraculus species indicate that bbs work for the first food.
 
10 days post hatch is pretty good in my book! I only made it to day 6 so far.  Do you have an estimate on the stocking density of the larvae? Of the food items you are adding?  What size/shape container are they in? Do you do water changes?  Do you try to remove/flush out the old prey items? How are you aerating?
 
If the smaller ones are alive and the larger ones are dead, then perhaps it was a problem during the molt to the next stage...maybe you need better water quality or more gentle aeration?  

I just looked at some of my emerald larvae under my scope. I'm in day 3, and I pulled two that looked white-ish (I thought they may acually be dead ones) and one darker one. Under the scope I found that the two whiter ones were zoea two and the darker one was still zoea one. If I see one spread out instead of in a tight ball it is usually dead.

Not sure of that helps or not.

I don't have access to a microscope, but it sounds like what your seeing with yours. The larger white ones are dead and the smaller darker ones are alive.  It may be a water quality issue, I haven't done anything with the water as far as water changes or filtration, could that be the problem? She is releasing larva every two weeks like clockwork so I will have more opportunities. my goal before next release is to build a kreisel and see if that helps.  Thanks for the input.
Greg

how did you guys get a pair? did you sex them or just add a bunch and wait for the remaining two to spawn?
 

Someone mentioned on a Mithrax thread how you sex them (females have wider carapaces or something) but I just bought four and hoped for the best.

Here's the thread:
http://www.mbisite.org/Forums/tm.aspx?m=80215

Post #14, I believe, mentions sexing them

gpreef, I've been thinking about your day 10 die off... Are you SURE that everything is dead?  Have you bastered the bottom gunk out and put it in some sort of flat container (I use clear-ish tupperware containers) and looked at it VERY closely with a flashlight or other bright light?  Because around day 10 is when they would become crabs, but the crabs are incredibly difficult to spot (teeny teeny tiny things) unless you are really looking for them.  And even then, they are easy to miss.