The captured goblin shark with the giant isopods. Photo: Carl Moore / Houston Chronicle www.chron.com
When fishermen hauled in a prehistoric-looking goblin shark from the Gulf of Mexico this month, marine biologists were astonished at the discovery of the rarely seen deep-sea creature.
But it seems their accidental find is even more remarkable.
Upon closer examination of photographs of the haul off Key West in Florida, a marine biologist spotted what he described as "freakin' giant isopods!"
The isopods were crustaceans such as slaters, commonly found in Australian gardens. But the ones shown in the photographs were "about the size of a house cat", Californian marine biologist Andrew Thaler said.
He told CNN that giant isopods were common in the deep sea, but spotting them was rare because they were usually very spread out.
He suggested that the goblin shark and the giant isopods might have been attracted to a rotting whale carcass, which would explain the rare haul.
“[Giant isopods are] usually spread pretty thin and only occur in abundance around a food source,” Mr Thaler told the Houston Chronicle.
“So, I hypothesized that the trawl might have passed over a whalefall, which would also explain the goblin shark.”
He told CNN that food sources in the deep sea were extremely rare, and the creatures could have gorged on a whale carcass and survived for months.
Fisherman Carl Moore and his crew were trawling for shrimp on April 19 when they pulled in their unusual haul from a depth of 600 metres.
The goblin shark was bright pink with a long snout hiding racks of sharp teeth, and Mr Moore said he had no idea what it was.
“I didn’t get the tape measure out because that thing’s got some wicked teeth. They could do some damage," he told the Houston Chronicle.
“My three-year-old grandson just loves sharks, so I’ve been taking pictures of every one we find. When I showed him this one he said, 'Wow, Pappa!’”
The shark was still alive, so Mr Moore released it after taking some photographs, which he later forwarded to the National Oceanic and Atmospheric Administration.
Mr Moore is thought to be one of only about 10 people to have seen a goblin shark alive. It usually lives in deep waters off the coast of Japan, and the last sighting was a decade ago.
The animal's long snout is believed to have electrical sensors so it can find prey even when it can't see or hear, and its jaw is said to operate like a venus fly trap.
David Schiffman, a marine biologist at the University of Miami, told the Houston Chronicle that he not believe a goblin shark would ever be found in the Gulf of Mexico.
"At first I wasn't sure if it was even possible for this to happen, but then, when the photos came through, it is undeniably a goblin shark. It's a shark ... that's pink!" he said.