Tag Archives: foreheads

Caught male Spotted Ratfish (Hydrolagus colliei) showing the [extended/erect] frontal clasper (tenaculum) on the front of the head. Credit: Gareth J. Fraser, University of Florida Male ghost sharks use tooth-studded rods on their foreheads for mating. Fossil and genetic evidence prove they are true teeth, showcasing evolutionary flexibility. Male “ghost sharks,” eerie deep-sea fish known as chimaeras and closely related …

It’s easy to assume that teeth always grow inside mouths, yet a new study has revealed that some animals – such as the spotted ratfish (Hydrolagus colliei) – grow them elsewhere. Sometimes referred to as ‘ghost sharks’, adult male spotted ratfish have strange-looking hooked protrusions that appear on a head structure called the tenaculum, which the fish use to grasp …