Gastrocystis is a medical term that refers to a condition where a cyst forms in the stomach. The spelling of the word "gastrocystis" can be broken down into its phonetic components. "Gas-tro-cy-stis" is pronounced as /ˈɡæs.trəˌsɪs.tɪs/. In this phonetic transcription, the 'g' is pronounced as a hard 'g' sound, the 'a' is pronounced as a short 'a' sound, the 's' is pronounced as a soft 's' sound, the 't' is pronounced with a hard 't' sound, and the 'i' is pronounced as a short 'i' sound. The final 's' is pronounced as a soft 's' sound.
Blastodermic vesicle, blastocyst.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
There is no widely recognized term "gastrocystis" in the field of etymology. It might be a misspelling or a term specific to a certain field or context. If you can provide more information about its origin or context, I may be able to assist you further.