For years, experts were in the dark as to what caused the bizarre seabed markings off the coast of New Zealand, which was discovered a decade ago. Finally, they were able to explain and identify the culprit.

Bizarre Seabed Markings Explained

These horseshoe-shaped footprints on the ocean floor were first discovered by researchers in 2013 off the coast of New Zealand at a depth of about 1,600 feet. The enigma was solved by Darren Stevens, an NIWA fisheries scientist, and Sadie Mills, an invertebrate collection manager at the National Institute of Water and Atmospheric Research (NIWA) in New Zealand.

Stevens said in a NIWA statement that Sadie gave him a lot of photographs from the survey and wondered whether they had been created by a deepsea rattail, commonly known as a grenadier.

According to her, they might have witnessed lebensspuren, a German term for "life traces" that describe the environmental remnants of physical existence. They initially wondered whether the traces might be those of a rattail searching the sediment for its next meal.

The researchers compared the imprints on the seabed to the contours of the heads of particular kinds of rattail fish, long, thin, deep-sea fish. The images blended together almost seamlessly.

The head profile photographs astonished Stevens because they matched the impressions well, despite his initial suspicion that it would work. Due to their distinctive head features, kinds of rattails have a long snout and an extensible mouth on the underside, head-which enable them to feed off the seafloor; unlike other species, they can identify the particular species behind the markings.

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What's a Deep-Sea Rattail?

Rattail fish, also called grenadier, is a group with different species worldwide. According to Dr. Jeffrey Drazen from the University of Hawaii, there are about 400 species of rattail worldwide. They are reportedly abundant on the planet, but much of its biology remains a mystery.

Their body tapers down to a tiny tail, resembling a rat, hence the name. Their enormous blue eyes aid them in locating prey in the murky depths of the ocean.

The typical grenadier is a large-headed fish with a tapering body, and a long, rat-like tail bordered above and below by the anal and second dorsal fins. The mouth is on the underside of the head, and the eyes are big. The frequently expanded nose probably helps while rummaging around in the mud for food. Some species have sound-producing paired muscles linked to the swim bladder, whereas others have light organs. The fish is typically between 1 and 2 feet (30 to 60 cm) long.

Rattail fish often hang out near the seafloor. All videos featuring them were shot off the western North American coast, from the Pacific Northwest to the Gulf of California. They span a wide range of depths, from the comparatively shallow Monterey Canyon depth of 1,500 feet to more than 13,000 feet off the Santa Barbara coast.

Drazen said there's no safe way to fish rattails, and fishing for them would cause a collapse in their population. He added that the greatest ecosystem on our planet, the deep sea, contains a variety of fish that are very plentiful, highly diversified, and frequently among the top predators, implying that they should be left alone.

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