Acantharia

Acantharia are a group of single-celled eukaryotes belonging to the superclass Actinopoda. They are characterized by their skeletons, which are made of strontium sulfate. These microscopic organisms are found in the upper layers of oceans worldwide.1234

Protists, like Acantharia, are a diverse group of eukaryotic organisms that are not animals, plants, or fungi. They can be single-celled, multicellular, or colonial, and exhibit a wide range of nutritional strategies, including photosynthesis, absorption, and ingestion. The complex cellular structures of protists set them apart from plant and animal cells.5