Fixation Fix in field in sea water as you collect. Use Aqueous Bouin, leave in aqueous bouin (which also decalcifies) for 1 or 2 days (maybe only 1 day if species is not heavily calcified). Then overnight in 70% Ethyl alcohol. Then stain: Stain could be: 1) Alumate carmine 2) Groat haematoxylin 3) Haemalum masson Then dehydrate & mount in canada balsam. If using a neutral fixative which does not decalcify use 10% ammonium citrate - this is for histologic stains. AVOID trichloacetic acid for histology of any kind as this destroys the tissues. (it may decalcify but it destroys everything else). Also AVOID EDTA because you will have the same problems.