Triquetra (; Latin tri- "three"and quetrus "cornered") originally meant "triangle"and was used to refer to various three-cornered shapes. Nowadays, it has come to refer exclusively to a particular more complicated shape formed of three vesicae piscis, sometimes with an added circle in or around it.

Temporary cyst formation of Heterocapsa triquetra (Dinophyceae) in natural populations
Red tide of the dinoflagellate Heterocapsa triquetra (Dinophyta) in a ferry-mixed coastal inlet
Nuclear genome sequence survey of the Dinoflagellate Heterocapsa triquetra
Red tide of the dinoflagellate Heterocapsa triquetra (Dinophyta) in a ferry-mixed coastal inlet
Induced phagotrophy in the photosynthetic dinoflagellate Heterocapsa triquetra
Seasonal niche strategy of the bloom-forming dinoflagellate Heterocapsa triquetra
Substitutional editing of Heterocapsa triquetra chloroplast transcripts and a folding model for its divergent chloroplast 16S rRNA.
Development of a deep chlorophyll maximum of Heterocapsa triquetra Ehrenb. at the entrance to the Gulf of Finland
Effects of UV-B radiation on synthesis of mycosporine-like amino acid and growth in Heterocapsa triquetra (Dinophyceae)
Competition for phosphorus between two dinoflagellates: A toxic Alexandrium minutum and a non-toxic Heterocapsa triquetra