The painted hornshark holotype specimen
Credit: CSIRO Australian National Fish Collection
The second shark to be described was the painted hornshark (Heterodontus marshallae). Previously thought to be zebra bullhead sharks (Heterodontus zebra), due to their very similar skin patterns. But once Will and Helen compared genetics, appearance and egg cases, they determined that the sharks were actually 2 different species.
Painted hornsharks are found only off north-western Australia at depths of 125 to 230 metres and they have an unusual set of teeth. The front of their mouth has shark-like teeth, while the back has rows of human-like molars to crush their hard-shelled prey!
New species need a holotype – the specimen from which the species can be formally described. Fortunately, at the end of 2022, while Will and Helen were surveying Western Australia’s Gascoyne Marine Park, they collected a 54-centimetre male. This male was in perfect condition, allowing it to become the painted hornshark holotype. This will support future research on this new, unusual shark.