16ft great white shark found with perfectly circular hole in its head – scientists know exactly what caused it

Researchers studying great white sharks have developed a formal classification system to interpret scars and wounds found on these apex predators. A study published in Frontiers in Marine Science details how specific injuries act as indicators for a shark’s migration patterns, mating habits, and interactions with other marine species.

Scot Anderson from the California White Shark Project explains that scars provide a historical account of the animal's life. One notable example features a 16ft female great white shark with a perfectly circular wound on her head. Scientists identified this mark as a bite from a cookiecutter shark, a parasitic species that removes small plugs of flesh. These wounds typically occur during the shark's offshore migration phase when their habitats overlap.

The research team categorizes various marks to decode shark behavior. Parallel cuts with even spacing often indicate contact with a boat propeller, while specific rope burns suggest entanglement in fishing gear. Parasitic copepods leave distinct dot patterns, and mating encounters often result in healed bite marks on the head and pectoral fins of females. These indicators allow scientists to estimate when and where great white sharks might be mating, a biological process that remains largely unobserved in the wild.

This new system provides a standardized method for marine biologists to record and analyze data from visual observations. By documenting these physical markers, the project builds a better understanding of how sharks navigate their environment and survive encounters with both prey and human-made objects. Each scar serves as a record of a specific event in the life of a shark, helping experts bridge gaps in current scientific knowledge regarding shark biology and ecology.