Trichosphaerium is a polymorphic, multinucleated, marine amoeba. It contains spicules consisting of calcium carbonate embedded in the glycocalyx covering that encapsulates the cell membrane. Microbial eukaryotes usually have definite shape and very few are observed to show multiple morphologies that reflect their life cycle and development. Trichosphaerium is poorly studied and there is no conclusive data linking its morphology with its life cycle. To better understand the correlation of the different morphotypes (cell forms) observed in Trichosphaerium with its life cycle and development, we examined the amoeba using different culturing techniques and light and confocal microscopy. Study of its morphology using microscopy techniques revealed that the amoeba assumes six common morphotypes including smaller round shaped, medium sized amoeba cell of various forms (seashell, horn, elongated shape, double-sided) and very large morphotypes of rectangle or irregular shapes. Immunocytochemistry (ICC) staining of the amoeba was conducted in order to observe the number of nuclei and their ploidy levels in the different morphotypes described. Results show that the number of nuclei differs between the different morphotypes. In some morphotype evidence of polyloidy, large fused nuclei, were observed. The morphotypes with polyploidy nuclei might be a reproductive stages indicating that Trichosphaerium undergoes sexual reproduction.
