Theca is the body armor that overlays the surface of many members of
Peridiniales and
Gonyaulacales (under Peridiniphycidae), including
Heterocapsa. It is mainly composed of cellulose secreted in the
Amphiesmal Vesicles, which is right beneath the cell membrane and serves important functions and characters to dinoflagellates, as they are of
SAR Super group. In
Heterocapsa, the arrangement of theca is crucial for the identification of
species Body scales Body scales is a very unique shared feature of
Heterocapsa. It has been widely studied to identify certain species. However, no previous study had pounded the question of how does
Heterocapsa produce its body scales. Some had speculated such process may be involved with the Golgi Apparatus, as scales were observed inside vesicles. Morphology of the body scales is a common triradiate basal plate, with vertical spines and longitudinal bars constructed on top of basal plate.
Organelles Like many other Dinoflagellates, the nucleus of Heterocapsa contains large amount of genetic information. Named
Dinokaryon, DNA found inside is intensely condensed into a
Liquid Crystal State. Being
photosynthetic, which isn't commonly seen in Dinoflagellates,
Heterocapsa possesses reticulated
chloroplast and
pyrenoid. As suggested by Iwataki, 2008 The hemolytic toxin produced by
H.circularisquama is lethal to bivalves and fishes, with reports of cardiac arrest to oyster farms in western Japan. Though the mechanism of toxin production is still unknown, some suggested the endosymbiotic bacteria may have participate in the process. == Species ==