tetragonidiaceae tetragonidiaceae tetragonidiaceae is a family of cryptomonads which includes two genera. members of tetragonidiaceae are distinguished from other cryptomonads by reproduction occurring in a non-motile vegetative phase, as well as the formation of multicellular filaments unlike any other cryptomonad family. tetragonidiaceae scientific classification domain: eukaryota (unranked): hacrobia (unranked): cryptista phylum: cryptophyta class: cryptophyceae order: tetragonidiales family: tetragonidiaceaebourrelly ex silva 1980 genera bjornbergiella tetragonidium