X-Rays reveal the biting truth about parrotfish teeth

Interwoven crystal structure is key to coral-crunching ability

So, you thought the fictional people-eating great white shark in the film “Jaws” had a powerful bite. But don’t overlook the mighty mouth of the parrotfish – its hardy teeth allow it to chomp on coral all day long, ultimately chewing and grinding it up through digestion into fine sand. That’s right: Its “beak” creates beaches. A single parrotfish can produce hundreds of pounds of sand each year.

Now, a study by scientists – including those at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) – has revealed a chain mail-like woven microstructure that gives parrotfish teeth their remarkable bite and resilience.

The natural structure they observed also provides a blueprint for creating ultra-durable synthetic materials that could be useful for mechanical components in electronics, and in other devices that undergo repetitive movement, abrasion, and contact stress.

Matthew Marcus, a staff scientist working at Berkeley Lab’s Advanced Light Source (ALS) – an X-ray source known as a synchrotron light source that was integral in the parrotfish study – became intrigued with parrotfish during a 2012 visit to the Great Barrier Reef off of the coast of Australia.

>Read More on the ALS website

Image: Scientists studied the microstructure of the coral-chomping teeth of the steephead parrotfish, pictured here, to learn about the fish’s powerful bite.
Credit: Alex The Reef Fish Geek/Nautilus Scuba Club, Cairns, Australia

Direct and Efficient Utilization of Solid-phase Iron by Diatoms

A research team indicates that diatoms, can directly uptake iron from insoluble iron sediments, and thereby potentially affect atmospheric carbon dioxide level.

A research team from Columbia University indicates that diatoms, photosynthetic marine organisms responsible for as much as 20% of photosynthesis in the world’s oceans, can directly uptake iron from insoluble iron sediments, and thereby potentially affect atmospheric carbon dioxide level. Although iron is often present in the ocean, usually there is insufficient iron for diatoms and other organisms to grow quickly unless this iron is dissolved and in a form that can be used readily. This research establishes that iron from mineral phases can be quite bioavailable, and that the diatoms can use most forms of iron, but appear to have a preference for a specific form of iron, ferrous iron, in the mineral phases. This research is applicable to a wide variety of questions in earth and ocean sciences, including basic biology of nutrient acquisition, the coupling of physical and geological processes such as glaciers to climate and geoengineering.

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Picture: Glacial striations seen near Upsala Glacier, Argentina, where scientists collected glacial samples. This physical scraping produces sediments and dust that can fertilize plankton when it is delivered to the ocean.
Photo by Michael Kaplan/Lamont-Doherty Earth Observatory