New findings call into question one of the core assumptions about teeth. Adult male spotted ratfish, a shark-like species native to the eastern Pacific Ocean, have rows of teeth on top of their heads, lining a cartilaginous appendage called the tenaculum, in addition to those in their jaws. They used their tenaculum teeth to grip females while mating in water.

Male “ghost sharks” — eerie deep-sea fish known as chimaeras that are related to sharks and rays — have a strange rod jutting from their foreheads, studded with sharp, retractable teeth. New research reveals these are not merely lookalikes, but real rows of teeth that grow outside the mouth.

Two outstanding researchers at Goethe University have each successfully secured a prestigious fellowship from the European Research Council (ERC) for their pioneering research projects: Geoscientist Dr. Jeremy McCormack, within the framework of his ERC Starting Grant, is investigating to what extent the ecology of prehistoric sharks increased their risk of extinction. Chemist Dr. Andrei Kuzhelev is advancing an ultra-high-resolution nuclear magnetic resonance spectroscopy to study the dynamics of complex biomolecules in nanoliter-sized samples. The grant are each endowed with around 1.5 million euros.

Climate change is causing the oceans to become notably more acidic. This could become a problem for sharks, as a team of biologists headed by Heinrich Heine University Düsseldorf (HHU) has discovered. In the scientific journal Frontiers in Marine Science, the research team describes that a more acidic environment weakens the teeth of sharks, causing them to break more easily, which in turn causes the predators to lose their bite.

Researchers studied a population of endangered whale sharks in the Bird’s Head Seascape off Indonesian Papua over a period of 13 years. In total, they observed 268 unique individuals, almost exclusively young males. 77% had visible scars or injuries from human-made causes such as rubbing against fishing platforms or boats. Only 17.7% had serious injuries like amputations or lacerations from boat propellers. Simple modifications to fishing platforms and boats should be effective in protecting local whale sharks from injury or scarring.

A leading cause of a rising pH value in the world’s oceans is human CO2 emission. As more CO2 is released into the atmosphere and absorbed by the oceans, the water becomes more acidic. This poses problems for many organisms – including sharks, a new study showed. Scientists incubated shark teeth in water with pH levels that reflect the current ocean pH, and in water with a pH value that oceans are predicted to reach by 2300. In the more acidic water of the simulated scenario, shark teeth, including roots and crowns, were significantly more damaged. This shows how global changes reach all the way to the microstructure of sharks’ teeth, the researchers said.

The sliteye shark has been recorded for the first time on the Great Chagos Bank, the world’s largest coral atoll structure—marking a major advance in understanding the geographic range of this near-threatened species.