Five viper dogfish were caught off the coast of Taitung in Taiwan by the Taiwanese Fisheries Research Institute earlier this week. The organization had been conducting a survey on local fish when they came across this extraordinarily rare and unusual haul.
Sadly, all except one were dead by the time they’d been pulled up out of the ocean. The lone survivor died the following day, but wildlife experts hope all five bodies can be used to find out more about this little-studied, little-understood fish.
The viper dogfish – which is actually a breed of shark – is so extremely shy and evasive (despite its appearance) that it bumbled along undisturbed by human activity for centuries. It was not discovered until 1986 and didn’t receive official recognition until four years after that.
The major reason for this is that they lurk deep underwater in the Pacific Ocean around the coasts of Hawaii, Japan, and Taiwan. This particular batch was found at depths of 350 meters (1,148 feet), according to local news reports.
As far as we know, they live in waters 270 to 360 meters (890 to 1,180 feet) below sea level, but experts reckon their habitat could go even deeper than that. This is because the specimens we come across are found during night-time fishing expeditions and it is likely that viper dogfish, like many deep-sea animals, migrate vertically to feed when the sun goes down.

Another factor is their unassuming appearance and small size. Dave Ebert, program director at Pacific Shark Research Center, believes they are caught more often than reported.
"I suspect they may be caught a bit more, but unless someone knows what they are or is keenly interested in these 'lost sharks' they usually go unreported," Ebert told Earth Touch News.
Viper dogfish are also tiny, which could mean that they slip through nets and go undetected. From snout to tail tip, they don't grow to more than 54 cm (21 inches). Females tend to be a little larger than males.
Viper dogfish are a breed of lantern shark, which puts them in the same family as the ninja shark, the southern lantern shark, and the recently discovered Etmopterus lailae. While it might look like something out of your nightmares, they are, in reality, completely harmless to humans.
Instead, they prefer to feed on crustaceans and bony fish, and snare prey (probably whole) with their needle-like teeth and extendable jaws. In fact, their jaws are such an impressive and distinctive feature, it’s how they got their scientific name, Trigonognathus, which literally translates to “a triangle jaw”.