A decades-old mystery involving "hoof-shaped" marks on the ocean floor near New Zealand has been solved. Researchers identified them as bite marks left by deep-sea grenadier or rattail fish, shedding light on their feeding habits at great ocean depths.
It looks like the mystery surrounding some "hoof-shaped" traces found on the ocean floor may have finally been answered.
The National Institute of Water and Atmospheric Research (NIWA) of New Zealand originally discovered the markings, which are located off its coast, back in 2013.
At 450 meters deep, a survey carried out on an underwater ridge turned up a scattering of what appeared to be hoof prints. Then, probably not a horse.
It hasn't been evident for the past ten years what produced the markings, but researchers now believe they know why.
Marine biologist Sadie Mills from NIWA said: "NIWA uses a technology called the Deep Towed Imaging System (DTIS) to allow us to see the seafloor in stunning detail.”
"When our people review this footage, they often see markings in the sediment, but unfortunately, most of them are unknown to science and we can only guess what might have made them, let alone find convincing proof."
Scientists believe they have figured out what caused these specific marks, though.
The mystery of the past ten years has now been solved by a new study.
The patterns, according to scientists, seem to match the mouth shape of a kind of fish known as deep-sea grenadiers or rattail fish precisely.
From what the researchers can tell, the markings are probably "bite marks" left by the fish biting into the mud in search of food.
Mills said: "It is so cool to finally have the validation that what we saw on the video was actually rattails feeding in the mud.”
"It's like getting a nice reward at the end of many years of watching DTIS footage."
Stevens added: "The reason we could point to a specific species is because of their unique head features – these types of rattails have a long snout and an extendable mouth on the underside of their head that allow them to feed off the seafloor, something that other species do not.”
"I had a hunch this might work but I was really surprised how well the head profile images matched the impressions."
Since this is some of the only material known to exist illustrating the eating habits of grenadiers, the discovery is all the more intriguing.
The fish often search for food at such extreme depths that it is "rarely if ever, encountered" to see their bite marks.
In addition to unraveling the enigma of the "hoof prints," the researchers also reported not being aware of any recorded evidence of the natural foraging behavior of this specific breed.
This provides an intriguing new perspective on the fish's dietary preferences.
The "hoof-shaped" markings, which had baffled scientists for so long, now offer a valuable glimpse into the world of deep-sea grenadiers.