What defines the mouth placement of the viper dogfish?

Answer

It is positioned terminally at the front

Unlike many shark species that possess a ventrally located mouth on the underside of the head, the viper dogfish features a terminal mouth. This means the mouth is located at the very front of the head. This specific positioning, combined with the shark's ability to create a massive gape, enables it to engulf its prey head-on, which is a highly effective hunting strategy in the deep sea.

What defines the mouth placement of the viper dogfish?
oceanfactsharkviper sharkdogfish