Fishermen in the Gulf of Mexico were shocked when they hauled a shrimp net up to discover they had caught a rare, and slightly terrifying, Goblin shark.

The mysterious sharks can live at depths of more than 1,300 metres.

On April 19, shrimp boat captain Carl Moore and his crew had set nets off the western shore of Key West, Fla., in search of Royal Red shrimp. When the net made it to the surface, however, the fishermen realized they had wrangled a Goblin shark.

Goblin sharks are most commonly found as bycatch in fishing nets in deep-water canyons around the coast of Japan. This is only the second known instance of a Goblin shark turning up in fishing nets in the Gulf of Mexico. The first was in 2002. (Carl Moore/NOAA) Goblin sharks are a rare and largely mysterious shark species that can live at depths of more than 1,300 metres, often near the steep drop-offs of continental shelves and within deep-water canyons. Most sightings have been by Japanese crews fishing in the cold, deep waters in and around the islands of Japan.

In 2003, after a large deep sea earthquake rattled the ocean floor near Taiwan, more than 100 Goblin sharks were pulled from the depths by fishermen in just a few days.

Moore's catch, which he estimated to be about 5.5 metres in length, is only the second Goblin shark to be recorded in the Gulf of Mexico. The first was more than 10 years ago, and was so unexpected that a scientific paper was published chronicling the find.

Moore immediately released the shark after freeing it from the net and reported the catch to the National Oceanic and Atmospheric Administration (NOAA) last week after returning to shore from a weeks-long fishing expedition.

"I didn't even know what it was. I didn't get the tape measure out because that thing's got some wicked teeth — they could do some damage," Moore told the Houston Chronicle, the newspaper that first reported on the unusual catch.

The NOAA released a statement on its Facebook page last week saying that fisheries biologists are working with Moore to get as much information as possible about the specimen caught in April.