Hexanchid
The Hexanchidae family comprises a group of deep-sea sharks commonly known as cow sharks or bluntnose sharks. This family is part of the order Hexanchiformes, which is one of the most ancient lineages of sharks, dating back over 125 million years. Hexanchid sharks are characterized by their broad, rounded snouts, five gill slits (a unique feature among sharks), and relatively small size, typically ranging from 1 to 3 meters in length.
The family includes three genera: *Hexanchus*, *Notorynchus*, and *Heptranchias*. The broadnose sevengill shark (*Notorynchus cepedianus*) is
Hexanchid sharks are primarily found in deep waters, often exceeding 200 meters in depth, though some species
Reproduction in hexanchids is ovoviviparous, meaning embryos develop within eggs that remain inside the mother’s body
These sharks play an ecological role in maintaining the balance of deep-sea ecosystems, and their study provides