[Histonet] oysters larvae again

[Anne-Sophie MARTINEZ]

Hello,
(1) I plan to fix oysters larvae/juveniles (4 month) for in toto ISH. 
Which fixative is the best : Davidson (10% formaldehyde 37-40%, 30% 
ethanol 95%, 60% seawater, 10% acetic acid) or MEMPFA-T (0,1 M Mops pH 
7,4; 2 mM EGTA; 1 mM MgSO4; 4% paraformaldehyde; 0,1% Tween 20)?
(2) Would it be possible to use the MEMPFA-T to fix and "decalcify" the 
shelves of the juveniles for TEM (embedding in type lowyril, unicril, 
LR-white resins) instead of classical fixative (4% PFA) and then EDTA?
Thank you very much again.
Anne-Sophie