The scope of your question is a bit ambiguous, but to add to what was already written, clean your petridishes or
whatever container you use to collect embryos. You often see fungal hyphae arise from fecal matter and unfertilized
eggs (unfertilized eggs are darker and often appear to have an erupting egg yolk) deposited along with the embryos. After
you collect the embryos thoroughly clean them, transfer them to a new petridish and top it off with embryonic medium.
Methylene blue works, but is not necessary, it can stain cells and can kill a fish systems biofilter, which could lead to a
whole other set of problems.
I have not heard of "white mosquito larvae" many labs use paramecium or rotifers. Either way make sure your not
overfeeding, and your culture is clean. Check to see if there is a lot of mosquito larvae still with the fish an hour after
feeding if so you might be overfeeding (or in the case of really young fish be sure that they can actually digest
their food, too big etc).
Some fungi are common in adult housing systems, such as saproglegnia, but nursery containers need to be clean.
David G White
H225 Zebrafish Lab
University of Washington
Department of Biological Structure
HSB G514 Box 357420
1959 NE Pacific Street
Seattle, WA 98195-7420
On Thu, 4 May 2006, christian lawrence wrote: