Marine Vertebrate Collection Manager Ben Frable shared this photo of a young Gulper eel, Saccopharynx lavenbergi, that was brought up off the coast of San Diego from about 500 to 700 meters (550 to 750 yards) depth by undergraduate marine biology majors during a one-day cruise last month.
This was only the 11th specimen of that species that's been collected by Scripps, Frable said, and this eight-inch specimen was intact down to the light organ on its tail.
"It's a very rare fish and they're usually found a lot deeper, below 1,000 or 1,500 meters," said Frable.
Asked about the popular image on Twitter, Frable explained that the dark spot in the middle of the eel's body isn't ink, as you might expect.
"Most midwater fishes have heavily pigmented guts to block bioluminescence being given off by their prey," Frable wrote. "Lest they become glowing prey items themselves."
The one-day cruise aboard Scripps Oceanography's Robert Gordon Sproul was for the Marine Biology Laboratory class SIO 136, which is intended to give undergraduate students experience aboard a research vessel and familiarize them with the instruments and tools used to collect oceanographic data and specimens while at sea.