Chemical Decapsulation of Resting Cysts of the Anostracans Artemia Franciscana and Streptocephalus Seali as Revealed by Scanning Electron Microscopy

Abstract

Chemical decapsulation of resting anostracan cysts involves removal of the tertiary envelope with a strong oxidant, typically a hypochlorite solution. Previously desiccated, commercially processed cysts of Artemia franciscana (San Francisco Bay strain) and undesiccated cysts of A. franciscana (Great Salt Lake strain) and Streptocephalus seali were treated with sodium hypochlorite for timed intervals. Oxidation of the tertiary envelope of cysts of Streptocephalus occurred by 240 s, whereas 840 s were required to completely decapsulate previously desiccated San Francisco Bay cysts of Artemia. The tertiary envelopes of undesiccated Great Salt Lake cysts of Artemia appeared undamaged through 480 s. The decapsulation process is documented sequentially with scanning electron photomicrographs. The evidence suggests that commercial processing of San Francisco Bay cysts of Artemia neither damages nor removes the outer membrane of the tertiary envelope. This contradicts the current view.