Two-Headed Shark Is First of Its Kind
A rare find from the Mediterranean expands the number of animals that have been born with two heads.
Are two heads always better than one?
Scientists from Spain are asking that question after they published findings this month documenting the first ever case of a two-headed shark among egg-laying shark species. The research, published in the Journal of Fish Biology, describes an Atlantic sawtail catshark embryo.
This catshark (Galeus atlanticus) lives only in the western Mediterranean, at depths of 330 to 710 meters (1,082 to 2,329 feet), and is considered near threatened. While studying the fish’s cardiovascular system, the scientists found an embryo with two heads, each with its own mouth, set of eyes, brain, and gill openings. The embryo had a single intestine but two sets of stomachs and livers.
When an animal has two heads it is