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Microscopic Worlds 1: Bugs of the ocean

Figure 6.2. What is that sitting on the end of the rad spine?

Figure 6.3. Each species of radiolarian produces a skeleton that has a characteristic shape. Their variety and beauty amazes and delights both scientists and artists.

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radiolaria

Figure 6.4. The end of this specimen has either collapsed or been dissolved.

But note that other much smaller microfossils are attached. Any ideas

what these might be?

Figure 6.5. Radiolus – a feeble sunbeam. The cell that constructed this

‘skeleton’ is long gone.

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Microscopic Worlds 1: Bugs of the ocean

Figure 6.6. In this close-up view, we are looking right inside the rad. Aren’t they fantastic!

Figure 6.7. This rad is like an Eiffel Tower in miniature.

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radiolaria

Rads are grazers and predators, and feed on diatoms, dinoflagellates, other single-celled bugs, and even tiny animals called copepods (we’ll meet copepods in Chapter 9). To trap a meal the radiolarian extends very fine strands of living cell material along parts of its skeleton. These entangle the prey, which is then drawn back into the main body of the radiolarian’s cell and dissolved.

Although most rad skeletons dissolve long before they could reach the ocean floor, they are very important microfossils and huge areas of the sea floor below the warm seas where most radiolarians occur are covered with radiolarian ooze. The oldest known fossil rads are over 500 million years old!

The geometry of radiolarians has long fascinated artists ever since their detail was first described about 150 years ago. Representations of their beautiful skeletons have been created as paintings, pencil drawings, and glass and pottery sculptures. One of the great

Figure 6.8. A close-up view of the mesh inside the latticework of

Figure 6.7.

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