Thalassiosira nordenskioeldii

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Thalassiosira nordenskioeldii

Everything on Earth relies on something else to ensure its survival. The Arctic food chain is very complex with each marine organism relying on another to complete the chain. In Arctic coastal waters small organisms, known as diatoms, act as the primary producers for this food web of life.

Image: A microscopic look at Thalassiosira nordenskioeldii.

3D View: Thalassiosira nordenskioeldii
Two bowhead whales swimming in water.

Why this species is important

Thalassiosira nordenskioeldii (its scientific name) is part of a group of diatoms upon which the entire marine planktonic Arctic food chain relies. These tiny living protists provide nutrients and food energy for other larger organisms that marine mammals such as whales and seals rely on for food.


The food web

The food web is an intricate chain in which all living things rely on something else to survive. The Arctic food web is one such chain.

This info graphic shows how just 1kg of a polar bear is reliant on a 10kg ringed seal. 1kg of a ringed seal’s energy is based on it consuming 10kg of fish. 1kg of fish requires 10kg of zooplankton while to create 1kg of zooplankton relies on 10kg of phytoplankton.

Looking at this chain overall, to create 1kg of a polar bear requires an extraordinary 10,000kg of phytoplankton.

An image showing a polar bear, a seal, fish, zooplankton and plankton.

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.