The single life
Diatoms reproduce sexually and asexually. Thalassiosira nordenskioeldii mainly grows in numbers asexually through mitosis, but during periods of stress can also reproduce sexually with the union of genetically unique cell forms.
A connecting chain
Thalassiosira nordenskioeldii cells contain threads that allow each individual to join to another, creating a bead-like chain. Under a microscope this chain resembles a necklace.
A floating colony
Each Thalassiosira nordenskioeldii contains long tubes called “portula” which house extra threads. These threads can be extended into the water allowing an entire colony to float.