Anglers are not the only ones who are targeting big fish; hairy anglerfish are also getting in on the action.
A CT scan recently performed on a British museum anglerfish specimen revealed the culprit behind the specimen’s large, bulging stomach.
The hairy anglerfish in question had been added to the Museum collection 13 years ago after being captured on a research cruise in the East Atlantic near the Cape Verde Islands in 1999. The vessel’s research log described the anglerfish’s capture as “an unusually large Caulophryne pelagica [anglerfish] was captured in perfect condition, due perhaps to a lethargy induced by a prodigious meal which had expanded the stomach in excess of the standard length.
Although it was apparent that the extended stomach on the fish was due to consuming a large meal, it was never known exactly what that meal was. Due to the rarity of the hairy anglerfish, scientists did not want to cut the fish open to reveal what was inside, thus ruining the specimen. Instead, it stayed preserved, along with the mystery of its last meal, in its jar of alcohol on a museum shelf.
However, the inside of the fish and the contents of its stomach have finally been revealed through a process known as micro-CT scanning. This process takes thousands of X-rays of a sample and then uses those images to create a 3D image. In this case, the process not only created an image of the anglerfish itself, but also of the creature that was in its stomach.
Watch the video to see the result:
The 3D image revealed that a fish twice the length of the anglerfish was folded up inside the anglerfish’s stomach. Upon closer inspection, the image also revealed one vital bit of information about the anglerfish’s prey; its otoliths. An otolith is a bone-like structure found in the skull that helps a fish to know which way is up. They are also unique to each fish species. Using that information, fish expert James Maclaine was finally able to identify the type of fish the anglerfish consumed before being captured.
Featured image via Natural History Museum UK